{"id":13,"date":"2025-10-31T00:25:51","date_gmt":"2025-10-31T00:25:51","guid":{"rendered":"https:\/\/vibromera.eu\/glossary\/iso-20816-3\/"},"modified":"2026-06-08T04:12:34","modified_gmt":"2026-06-08T04:12:34","slug":"iso-20816-3","status":"publish","type":"glossary","link":"https:\/\/vibromera.eu\/bn\/glossary\/iso-20816-3\/","title":{"rendered":"ISO 20816-3: \u09b6\u09bf\u09b2\u09cd\u09aa \u09ae\u09c7\u09b6\u09bf\u09a8\u09c7\u09b0 \u099c\u09a8\u09cd\u09af \u0995\u09ae\u09cd\u09aa\u09a8 \u09b8\u09c0\u09ae\u09be"},"content":{"rendered":"
\n\n\n \n \n ISO 20816-3: Vibration Limits for Industrial Machines \u2014 Calculator & Guide<\/title>\n <meta name=\"description\" content=\"Complete guide to ISO 20816-3:2022 vibration assessment for industrial machinery. Interactive calculator for zone classification (A\/B\/C\/D), housing and shaft vibration limits, measurement best practices, and Balanset-1A integration.\">\n <meta name=\"robots\" content=\"index, follow\">\n \n\n <meta property=\"og:title\" content=\"ISO 20816-3: Vibration Limits for Industrial Machines \u2014 Calculator & Guide\">\n <meta property=\"og:description\" content=\"Interactive vibration zone calculator and comprehensive technical guide for ISO 20816-3:2022. Determine zones A\/B\/C\/D for rotating equipment above 15 kW.\">\n <meta property=\"og:url\" content=\"https:\/\/vibromera.eu\/glossary\/iso-20816-3\/\">\n <meta property=\"og:type\" content=\"article\">\n\n <!-- Schema.org -->\n <script type=\"application\/ld+json\">\n {\n \"@context\": \"https:\/\/schema.org\",\n \"@type\": \"SoftwareApplication\",\n \"@id\": \"#iso20816-3-calculator\",\n \"name\": \"ISO 20816-3 Vibration Assessment Calculator\",\n \"description\": \"Engineering calculator for vibration assessment of industrial machinery per ISO 20816-3:2022. Determine vibration zones A\/B\/C\/D for rotating equipment with power above 15 kW and speeds 120-30000 r\/min.\",\n \"applicationCategory\": \"EngineeringApplication\",\n \"operatingSystem\": \"Web\",\n \"isAccessibleForFree\": true\n }\n <\/script>\n <script type=\"application\/ld+json\">\n {\n \"@context\": \"https:\/\/schema.org\",\n \"@type\": \"TechArticle\",\n \"headline\": \"ISO 20816-3 Vibration Assessment Guide for Industrial Machinery\",\n \"description\": \"Practical vibration assessment calculator and comprehensive guide referencing ISO 20816-3:2022 for industrial machines above 15 kW.\",\n \"keywords\": \"ISO 20816-3, vibration, industrial machinery, vibration zones, bearing vibration, shaft vibration, condition monitoring, balancing\",\n \"articleSection\": \"Vibration Engineering\",\n \"inLanguage\": \"en\"\n }\n <\/script>\n <script type=\"application\/ld+json\">\n {\n \"@context\": \"https:\/\/schema.org\",\n \"@type\": \"BreadcrumbList\",\n \"itemListElement\": [\n {\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/vibromera.eu\/\"},\n {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Glossary\", \"item\": \"https:\/\/vibromera.eu\/glossary\/\"},\n {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"ISO 20816-3\", \"item\": \"https:\/\/vibromera.eu\/glossary\/iso-20816-3\/\"}\n ]\n }\n <\/script>\n <script type=\"application\/ld+json\">\n {\n \"@context\": \"https:\/\/schema.org\",\n \"@type\": \"FAQPage\",\n \"mainEntity\": [\n {\n \"@type\": \"Question\",\n \"name\": \"What is ISO 20816-3?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"ISO 20816-3:2022 is an international standard for measurement and evaluation of vibration on industrial machinery with power rating above 15 kW and operating speeds between 120 and 30,000 r\/min. It supersedes ISO 10816-3 and ISO 7919-3.\"\n }\n },\n {\n \"@type\": \"Question\",\n \"name\": \"What are vibration zones A, B, C, and D?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"Zone A: Newly commissioned machines in optimal condition. Zone B: Acceptable for unrestricted long-term operation. Zone C: Not suitable for continuous operation; remedial action required. Zone D: Vibration severe enough to cause damage; immediate action needed.\"\n }\n },\n {\n \"@type\": \"Question\",\n \"name\": \"How to classify machine as Group 1 or Group 2?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"Group 1: Power > 300 kW or electric machines with shaft height H > 315 mm. Group 2: Power 15\u2013300 kW or electric machines with shaft height 160 < H \u2264 315 mm.\"\n }\n },\n {\n \"@type\": \"Question\",\n \"name\": \"What is the difference between rigid and flexible foundation?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"A foundation is rigid if the lowest natural frequency of the machine-foundation system exceeds the main excitation frequency by at least 25%. All other foundations are flexible.\"\n }\n },\n {\n \"@type\": \"Question\",\n \"name\": \"Should I use velocity or displacement for assessment?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"For most machines above 600 r\/min, velocity is the primary criterion. Use displacement additionally for machines at or below 600 r\/min, or when significant low-frequency components are present.\"\n }\n },\n {\n \"@type\": \"Question\",\n \"name\": \"What is the difference between ISO 20816-3 and the old ISO 10816-3?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"ISO 20816-3:2022 supersedes ISO 10816-3 and ISO 7919-3, integrating housing vibration and shaft vibration criteria into a unified standard with updated zone boundaries and expanded guidance.\"\n }\n },\n {\n \"@type\": \"Question\",\n \"name\": \"How can balancing help meet ISO 20816-3 limits?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"Unbalance is the most common cause of excessive 1\u00d7 vibration. 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}\n .hero { padding: 32px 18px; }\n .res-item { flex-direction: column; align-items: flex-start; gap: 4px; }\n }\n <\/style>\n<\/head>\n<body>\n\n<!-- HERO -->\n<header class=\"hero\">\n <div class=\"hero-inner\">\n <nav class=\"breadcrumb\" aria-label=\"Breadcrumb\">\n <a href=\"\/\">Home<\/a><span>\u203a<\/span>\n <a href=\"\/glossary\/\">Glossary<\/a><span>\u203a<\/span>\n ISO 20816-3\n <\/nav>\n <h1>ISO 20816-3: Vibration Limits for Industrial Machines<\/h1>\n <p class=\"hero-sub\">Interactive calculator and comprehensive technical guide for vibration zone assessment of industrial machinery per ISO 20816-3:2022. Covers housing vibration, shaft vibration, measurement methodology, and field balancing with Balanset-1A.<\/p>\n <\/div>\n<\/header>\n\n<div class=\"page-wrap\">\n\n<!-- QUICK REFERENCE: Table A.1 -->\n<div class=\"qref\">\n <div class=\"qref-head\">\n <h2>\u2699 Table A.1 \u2014 Group 1 Machines (Large: >300 kW or H>315 mm)<\/h2>\n <\/div>\n <div class=\"qref-note\">RMS vibration velocity (mm\/s) and displacement (\u03bcm) \u00b7 10\u20131000 Hz \u00b7 Non-rotating parts<\/div>\n <div style=\"overflow-x:auto;\">\n <table class=\"zt\">\n <thead>\n <tr>\n <th>Zone<\/th>\n <th>Rigid \u2014 Vel. (mm\/s)<\/th>\n <th>Rigid \u2014 Disp. (\u03bcm)<\/th>\n <th>Flexible \u2014 Vel. (mm\/s)<\/th>\n <th>Flexible \u2014 Disp. (\u03bcm)<\/th>\n <\/tr>\n <\/thead>\n <tbody>\n <tr class=\"ra\">\n <td><span class=\"zl\"><span class=\"zd zd-a\"><\/span> A \u2014 Good<\/span><\/td>\n <td>< 2.3<\/td><td>< 29<\/td><td>< 3.5<\/td><td>< 45<\/td>\n <\/tr>\n <tr class=\"rb\">\n <td><span class=\"zl\"><span class=\"zd zd-b\"><\/span> B \u2014 Acceptable<\/span><\/td>\n <td>2.3 \u2013 4.5<\/td><td>29 \u2013 57<\/td><td>3.5 \u2013 7.1<\/td><td>45 \u2013 90<\/td>\n <\/tr>\n <tr class=\"rc\">\n <td><span class=\"zl\"><span class=\"zd zd-c\"><\/span> C \u2014 Limited<\/span><\/td>\n <td>4.5 \u2013 7.1<\/td><td>57 \u2013 90<\/td><td>7.1 \u2013 11.0<\/td><td>90 \u2013 140<\/td>\n <\/tr>\n <tr class=\"rd\">\n <td><span class=\"zl\"><span class=\"zd zd-d\"><\/span> D \u2014 Dangerous<\/span><\/td>\n <td>> 7.1<\/td><td>> 90<\/td><td>> 11.0<\/td><td>> 140<\/td>\n <\/tr>\n <\/tbody>\n <\/table>\n <\/div>\n<\/div>\n\n<!-- QUICK REFERENCE: Table A.2 -->\n<div class=\"qref\">\n <div class=\"qref-head\">\n <h2>\u2699 Table A.2 \u2014 Group 2 Machines (Medium: 15\u2013300 kW or H=160\u2013315 mm)<\/h2>\n <\/div>\n <div class=\"qref-note\">RMS vibration velocity (mm\/s) and displacement (\u03bcm) \u00b7 10\u20131000 Hz \u00b7 Non-rotating parts<\/div>\n <div style=\"overflow-x:auto;\">\n <table class=\"zt\">\n <thead>\n <tr>\n <th>Zone<\/th>\n <th>Rigid \u2014 Vel. (mm\/s)<\/th>\n <th>Rigid \u2014 Disp. (\u03bcm)<\/th>\n <th>Flexible \u2014 Vel. (mm\/s)<\/th>\n <th>Flexible \u2014 Disp. (\u03bcm)<\/th>\n <\/tr>\n <\/thead>\n <tbody>\n <tr class=\"ra\">\n <td><span class=\"zl\"><span class=\"zd zd-a\"><\/span> A \u2014 Good<\/span><\/td>\n <td>< 1.4<\/td><td>< 22<\/td><td>< 2.3<\/td><td>< 37<\/td>\n <\/tr>\n <tr class=\"rb\">\n <td><span class=\"zl\"><span class=\"zd zd-b\"><\/span> B \u2014 Acceptable<\/span><\/td>\n <td>1.4 \u2013 2.8<\/td><td>22 \u2013 45<\/td><td>2.3 \u2013 4.5<\/td><td>37 \u2013 71<\/td>\n <\/tr>\n <tr class=\"rc\">\n <td><span class=\"zl\"><span class=\"zd zd-c\"><\/span> C \u2014 Limited<\/span><\/td>\n <td>2.8 \u2013 4.5<\/td><td>45 \u2013 71<\/td><td>4.5 \u2013 7.1<\/td><td>71 \u2013 113<\/td>\n <\/tr>\n <tr class=\"rd\">\n <td><span class=\"zl\"><span class=\"zd zd-d\"><\/span> D \u2014 Dangerous<\/span><\/td>\n <td>> 4.5<\/td><td>> 71<\/td><td>> 7.1<\/td><td>> 113<\/td>\n <\/tr>\n <\/tbody>\n <\/table>\n <\/div>\n<\/div>\n\n<!-- QUICK REFERENCE: Annex B Shaft -->\n<div class=\"qref\">\n <div class=\"qref-head\">\n <h2>\u2699 Annex B \u2014 Shaft Vibration Limits (Displacement)<\/h2>\n <\/div>\n <div class=\"qref-note\">Peak-to-peak shaft displacement S(p-p) in \u03bcm \u00b7 Measured with proximity probes<\/div>\n <div style=\"overflow-x:auto;\">\n <table class=\"zt\">\n <thead>\n <tr>\n <th>Zone Boundary<\/th>\n <th>Formula<\/th>\n <th>@ 1500 rpm<\/th>\n <th>@ 3000 rpm<\/th>\n <th>@ 6000 rpm<\/th>\n <\/tr>\n <\/thead>\n <tbody>\n <tr class=\"ra\">\n <td><span class=\"zl\"><span class=\"zd zd-a\"><\/span> A\/B<\/span><\/td>\n <td>4800 \/ \u221an<\/td><td>124<\/td><td>88<\/td><td>62<\/td>\n <\/tr>\n <tr class=\"rb\">\n <td><span class=\"zl\"><span class=\"zd zd-b\"><\/span> B\/C<\/span><\/td>\n <td>9000 \/ \u221an<\/td><td>232<\/td><td>164<\/td><td>116<\/td>\n <\/tr>\n <tr class=\"rc\">\n <td><span class=\"zl\"><span class=\"zd zd-c\"><\/span> C\/D<\/span><\/td>\n <td>13200 \/ \u221an<\/td><td>341<\/td><td>241<\/td><td>170<\/td>\n <\/tr>\n <\/tbody>\n <\/table>\n <\/div>\n<\/div>\n\n \t\t<section class=\"woocommerce 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class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">€<\/span>124.00<\/span> + VAT (if applicable)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/bn\/wp-json\/wp\/v2\/glossary\/13?add-to-cart=1832\" data-quantity=\"1\" data-product_id=\"1832\" data-product_sku=\"Tach-1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 \"><i rel=\"tooltip\" data-original-title=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 \" class=\"fas fa-cart-plus\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/bn\/wp-json\/wp\/v2\/glossary\/13?add-to-cart=1832\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_1832\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"1832\" data-product_sku=\"Tach-1\" aria-label=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8: “Optical Sensor (Laser Tachometer)”\" rel=\"nofollow\" data-success_message=\"\u0986\u09aa\u09a8\u09be\u09b0 \u0995\u09be\u09b0\u09cd\u099f\u09c7 “Optical Sensor (Laser Tachometer)” \u09af\u09cb\u0997 \u0995\u09b0\u09be \u09b9\u09af\u09bc\u09c7\u099b\u09c7\">\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 <\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_1832\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/bn\/product\/balanset-4\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/bn\/product\/balanset-4\/\" title=\"Balanset-4\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Vibromera rotor balancing kit: carry case, multi-channel signal conditioner, handheld analyzer, magnetic base, vibration sensors, and coiled cables.\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-300x200.webp 300w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-18x12.webp 18w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-460x306.webp 460w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-600x400.webp 600w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-272x182.webp 272w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4.webp 640w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/bn\/product-category\/devices\/\" rel=\"tag\">Devices<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/bn\/product\/balanset-4\/\" title=\"Balanset-4\">Balanset-4<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t<div class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">€<\/span>6,803.00<\/span> + VAT (if applicable)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/bn\/wp-json\/wp\/v2\/glossary\/13?add-to-cart=1833\" data-quantity=\"1\" data-product_id=\"1833\" data-product_sku=\"BS-4\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 \"><i rel=\"tooltip\" data-original-title=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 \" class=\"fas fa-cart-plus\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/bn\/wp-json\/wp\/v2\/glossary\/13?add-to-cart=1833\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_1833\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"1833\" data-product_sku=\"BS-4\" aria-label=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8: “Balanset-4”\" rel=\"nofollow\" data-success_message=\"\u0986\u09aa\u09a8\u09be\u09b0 \u0995\u09be\u09b0\u09cd\u099f\u09c7 “Balanset-4” \u09af\u09cb\u0997 \u0995\u09b0\u09be \u09b9\u09af\u09bc\u09c7\u099b\u09c7\">\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 <\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_1833\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div><!-- \/.row --><div class=\"row\">\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/bn\/product\/magnet-stand\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/bn\/product\/magnet-stand\/\" title=\"Magnetic Stand Insize-60-kgf\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Magnet base.\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-600x400.webp 600w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-300x200.webp 300w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-1024x682.webp 1024w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-768x512.webp 768w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-272x182.webp 272w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36.webp 1280w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/bn\/product-category\/parts\/\" rel=\"tag\">Parts<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/bn\/product\/magnet-stand\/\" title=\"Magnetic Stand Insize-60-kgf\">Magnetic Stand Insize-60-kgf<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t<div class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">€<\/span>46.00<\/span> + VAT (if applicable)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/bn\/wp-json\/wp\/v2\/glossary\/13?add-to-cart=1852\" data-quantity=\"1\" data-product_id=\"1852\" data-product_sku=\"MS-1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 \"><i rel=\"tooltip\" data-original-title=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 \" class=\"fas fa-cart-plus\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/bn\/wp-json\/wp\/v2\/glossary\/13?add-to-cart=1852\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_1852\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"1852\" data-product_sku=\"MS-1\" aria-label=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8: “Magnetic Stand Insize-60-kgf”\" rel=\"nofollow\" data-success_message=\"\u0986\u09aa\u09a8\u09be\u09b0 \u0995\u09be\u09b0\u09cd\u099f\u09c7 “Magnetic Stand Insize-60-kgf” \u09af\u09cb\u0997 \u0995\u09b0\u09be \u09b9\u09af\u09bc\u09c7\u099b\u09c7\">\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 <\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_1852\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/bn\/product\/reflective-tape\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/bn\/product\/reflective-tape\/\" title=\"Reflective tape\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Reflective tape\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-16x12.webp 16w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-460x306.webp 460w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-272x182.webp 272w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/bn\/product-category\/parts\/\" rel=\"tag\">Parts<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/bn\/product\/reflective-tape\/\" title=\"Reflective tape\">Reflective tape<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t<div class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">€<\/span>10.00<\/span> + VAT (if applicable)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/bn\/wp-json\/wp\/v2\/glossary\/13?add-to-cart=2329\" data-quantity=\"1\" data-product_id=\"2329\" data-product_sku=\"rt-1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 \"><i rel=\"tooltip\" data-original-title=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 \" class=\"fas fa-cart-plus\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/bn\/wp-json\/wp\/v2\/glossary\/13?add-to-cart=2329\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_2329\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"2329\" data-product_sku=\"rt-1\" aria-label=\"\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8: “Reflective tape”\" rel=\"nofollow\" data-success_message=\"\u0986\u09aa\u09a8\u09be\u09b0 \u0995\u09be\u09b0\u09cd\u099f\u09c7 “Reflective tape” \u09af\u09cb\u0997 \u0995\u09b0\u09be \u09b9\u09af\u09bc\u09c7\u099b\u09c7\">\u0995\u09be\u09b0\u09cd\u099f\u09c7 \u09af\u09cb\u0997 \u0995\u09b0\u09c1\u09a8 <\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_2329\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/bn\/product\/dynamic-balancer-balanset-1a\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/bn\/product\/dynamic-balancer-balanset-1a\/\" title=\"Dynamic balancer \u201cBalanset-1A\u201d OEM\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Balanset-1A kit contents with interface unit, sensors, tachometer and accessories\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-600x400.webp 600w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-300x200.webp 300w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-1024x683.webp 1024w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-768x512.webp 768w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-1536x1024.webp 1536w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-2048x1366.webp 2048w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-272x182.webp 272w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-e1732998877834.webp 708w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/bn\/product-category\/devices\/\" rel=\"tag\">Devices<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/bn\/product\/dynamic-balancer-balanset-1a\/\" title=\"Dynamic balancer 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class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/section>\n\t\t\n\n<!-- TABLE OF CONTENTS -->\n<nav class=\"toc\">\n <div class=\"toc-label\">Contents<\/div>\n <ol>\n <li><a href=\"#calc\">Interactive Calculator<\/a><\/li>\n <li><a href=\"#s-scope\">Scope & Applicable Equipment<\/a><\/li>\n <li><a href=\"#s-class\">Machine Classification<\/a><\/li>\n <li><a href=\"#s-zones\">Understanding Zones A\u2013D<\/a><\/li>\n <li><a href=\"#s-criteria\">Evaluation Criteria I & II<\/a><\/li>\n <li><a href=\"#s-meas\">Measurement Best Practices<\/a><\/li>\n <li><a href=\"#s-housing\">Housing Vibration Limits<\/a><\/li>\n <li><a href=\"#s-shaft\">Shaft Vibration Limits<\/a><\/li>\n <li><a href=\"#s-alarms\">WARNING & TRIP Levels<\/a><\/li>\n <li><a href=\"#s-transient\">Transient Operation<\/a><\/li>\n <li><a href=\"#s-physics\">Physics & Signal Processing<\/a><\/li>\n <li><a href=\"#s-balancing\">Balancing Theory<\/a><\/li>\n <li><a href=\"#s-cases\">Case Studies<\/a><\/li>\n <li><a href=\"#s-mistakes\">Common Mistakes<\/a><\/li>\n <li><a href=\"#s-workflow\">Assessment Workflow<\/a><\/li>\n <li><a href=\"#s-standards\">Reference Standards<\/a><\/li>\n <li><a href=\"#s-faq\">FAQ<\/a><\/li>\n <\/ol>\n<\/nav>\n\n<!-- ===================== CALCULATOR ===================== -->\n<section class=\"calc-card\" id=\"calc\">\n <div class=\"calc-head\">\n <h2>Vibration Zone Assessment Calculator<\/h2>\n <p>Enter machine parameters and measured vibration to determine condition zone per ISO 20816-3<\/p>\n <\/div>\n <div class=\"calc-body\">\n <form id=\"calcForm\">\n <div class=\"form-row\">\n <div class=\"form-group\">\n <label for=\"c-power\">Machine Power Rating<\/label>\n <div class=\"input-wrap\">\n <input type=\"number\" id=\"c-power\" min=\"15\" step=\"any\" placeholder=\"75\" value=\"75\">\n <select id=\"c-power-unit\">\n <option value=\"kW\">kW<\/option>\n <option value=\"MW\">MW<\/option>\n <option value=\"hp\">hp<\/option>\n <\/select>\n <\/div>\n <span class=\"hint\">Minimum 15 kW for this standard<\/span>\n <\/div>\n <div class=\"form-group\">\n <label for=\"c-speed\">Operating Speed<\/label>\n <div class=\"input-wrap\">\n <input type=\"number\" id=\"c-speed\" min=\"120\" max=\"30000\" step=\"1\" placeholder=\"1500\" value=\"1500\">\n <span class=\"input-unit\">r\/min<\/span>\n <\/div>\n <span class=\"hint\">120 \u2013 30,000 r\/min<\/span>\n <\/div>\n <\/div>\n <div class=\"form-row\">\n <div class=\"form-group\">\n <label for=\"c-height\">Shaft Height (electric machines)<\/label>\n <div class=\"input-wrap\">\n <input type=\"number\" id=\"c-height\" min=\"0\" step=\"1\" placeholder=\"280\">\n <span class=\"input-unit\">mm<\/span>\n <\/div>\n <span class=\"hint\">IEC 60072 shaft centerline to mounting plane. Leave blank if unknown.<\/span>\n <\/div>\n <div class=\"form-group\">\n <label for=\"c-foundation\">Foundation Type<\/label>\n <select id=\"c-foundation\" style=\"width:100%;\">\n <option value=\"rigid\">Rigid (f_n > 1.25 \u00d7 running speed)<\/option>\n <option value=\"flexible\">Flexible (f_n \u2264 1.25 \u00d7 running speed)<\/option>\n <option value=\"unknown\">Unknown \/ To be determined<\/option>\n <\/select>\n <span class=\"hint\">Based on lowest natural frequency of machine-foundation system<\/span>\n <\/div>\n <\/div>\n <div class=\"form-row\">\n <div class=\"form-group\">\n <label for=\"c-mtype\">Measurement Type<\/label>\n <select id=\"c-mtype\" style=\"width:100%;\">\n <option value=\"bearing\">Bearing Housing (velocity)<\/option>\n <option value=\"shaft\">Shaft Relative (displacement)<\/option>\n <\/select>\n <\/div>\n <div class=\"form-group\">\n <label for=\"c-btype\">Bearing Type<\/label>\n <select id=\"c-btype\" style=\"width:100%;\">\n <option value=\"journal\">Journal (Sleeve) Bearings<\/option>\n <option value=\"rolling\">Rolling Element Bearings<\/option>\n <\/select>\n <\/div>\n <\/div>\n\n <!-- Bearing inputs -->\n <div id=\"bearingInputs\">\n <div class=\"form-row\">\n <div class=\"form-group\">\n <label for=\"c-vel\">Measured Velocity (RMS)<\/label>\n <div class=\"input-wrap\">\n <input type=\"number\" id=\"c-vel\" min=\"0\" step=\"0.01\" placeholder=\"3.2\">\n <span class=\"input-unit\">mm\/s<\/span>\n <\/div>\n <span class=\"hint\">Broadband 10\u20131000 Hz (or 2\u20131000 Hz for \u2264600 r\/min)<\/span>\n <\/div>\n <div class=\"form-group\">\n <label for=\"c-disp-b\">Measured Displacement (RMS) \u2014 optional<\/label>\n <div class=\"input-wrap\">\n <input type=\"number\" id=\"c-disp-b\" min=\"0\" step=\"0.1\" placeholder=\"\">\n <span class=\"input-unit\">\u03bcm<\/span>\n <\/div>\n <span class=\"hint\">Required for low-speed machines (\u2264600 r\/min)<\/span>\n <\/div>\n <\/div>\n <\/div>\n\n <!-- Shaft inputs -->\n <div id=\"shaftInputs\" class=\"hidden\">\n <div class=\"form-row\">\n <div class=\"form-group\">\n <label for=\"c-shaft-disp\">Shaft Displacement S(p-p)<\/label>\n <div class=\"input-wrap\">\n <input type=\"number\" id=\"c-shaft-disp\" min=\"0\" step=\"0.1\" placeholder=\"\">\n <span class=\"input-unit\">\u03bcm<\/span>\n <\/div>\n <span class=\"hint\">Maximum from two orthogonal proximity probes<\/span>\n <\/div>\n <div class=\"form-group\">\n <label for=\"c-clearance\">Bearing Diametral Clearance \u2014 optional<\/label>\n <div class=\"input-wrap\">\n <input type=\"number\" id=\"c-clearance\" min=\"0\" step=\"0.1\" placeholder=\"\">\n <span class=\"input-unit\">\u03bcm<\/span>\n <\/div>\n <span class=\"hint\">Check clearance limitations per Annex C<\/span>\n <\/div>\n <\/div>\n <\/div>\n\n <div class=\"btn-row\">\n <button type=\"submit\" class=\"btn btn-primary\">Assess Zone<\/button>\n <button type=\"button\" class=\"btn btn-secondary\" id=\"resetBtn\">Reset<\/button>\n <\/div>\n <\/form>\n\n <!-- RESULTS -->\n <div class=\"results\" id=\"results\">\n <div class=\"results-head\">Assessment Results<\/div>\n <div class=\"res-grid\">\n <div class=\"res-item\">\n <span class=\"res-label\">Machine Classification<\/span>\n <span class=\"res-value\" id=\"r-group\">\u2014<\/span>\n <\/div>\n <div class=\"res-item\">\n <span class=\"res-label\">Foundation Type<\/span>\n <span class=\"res-value\" id=\"r-found\">\u2014<\/span>\n <\/div>\n <div class=\"res-item\">\n <span class=\"res-label\">Measured Value<\/span>\n <span class=\"res-value\" id=\"r-val\">\u2014<\/span>\n <\/div>\n <\/div>\n\n <div style=\"padding:16px 20px 0;\">\n <h4 style=\"color:var(--navy);margin:0 0 8px;font-size:14px;text-transform:uppercase;letter-spacing:0.5px;\">Zone Boundaries Applied<\/h4>\n <div class=\"tw\">\n <table class=\"ct\" id=\"r-ztable\">\n <thead><tr><th>Boundary<\/th><th>Velocity (mm\/s)<\/th><th>Displacement (\u03bcm)<\/th><\/tr><\/thead>\n <tbody>\n <tr><td>A\/B<\/td><td id=\"r-ab-v\">\u2014<\/td><td id=\"r-ab-d\">\u2014<\/td><\/tr>\n <tr><td>B\/C<\/td><td id=\"r-bc-v\">\u2014<\/td><td id=\"r-bc-d\">\u2014<\/td><\/tr>\n <tr><td>C\/D<\/td><td id=\"r-cd-v\">\u2014<\/td><td id=\"r-cd-d\">\u2014<\/td><\/tr>\n <\/tbody>\n <\/table>\n <\/div>\n <\/div>\n\n <div id=\"r-shaft-table\" class=\"hidden\" style=\"padding:0 20px;\">\n <h4 style=\"color:var(--navy);margin:16px 0 8px;font-size:14px;text-transform:uppercase;letter-spacing:0.5px;\">Shaft Vibration Limits (Calculated)<\/h4>\n <div class=\"tw\">\n <table class=\"ct\">\n <thead><tr><th>Boundary<\/th><th>Formula<\/th><th>S(p-p) \u03bcm<\/th><\/tr><\/thead>\n <tbody>\n <tr><td>A\/B<\/td><td>4800\/\u221an<\/td><td id=\"r-s-ab\">\u2014<\/td><\/tr>\n <tr><td>B\/C<\/td><td>9000\/\u221an<\/td><td id=\"r-s-bc\">\u2014<\/td><\/tr>\n <tr><td>C\/D<\/td><td>13200\/\u221an<\/td><td id=\"r-s-cd\">\u2014<\/td><\/tr>\n <\/tbody>\n <\/table>\n <\/div>\n <\/div>\n\n <div class=\"zone-badge\" id=\"r-zone-badge\">Zone: <span id=\"r-zone-letter\">\u2014<\/span><\/div>\n <div class=\"rec-box\"><strong>Recommendation:<\/strong> <span id=\"r-rec\">\u2014<\/span><\/div>\n <\/div>\n <\/div>\n<\/section>\n\n<!-- ===================== CONTENT SECTIONS ===================== -->\n\n<!-- SCOPE -->\n<section id=\"s-scope\">\n<h2 class=\"section-title\">1. Scope & Applicable Equipment<\/h2>\n<p>ISO 20816-3:2022 establishes guidance for evaluating vibration condition of industrial equipment with power rating <strong>above 15 kW<\/strong> and rotational speeds from <strong>120 to 30,000 r\/min<\/strong>. Assessment is based on measurements of vibration on non-rotating parts and on rotating shafts under normal operating conditions.<\/p>\n\n<h4>This Standard Applies To:<\/h4>\n<ul>\n <li>Steam turbines and generators with power up to 40 MW<\/li>\n <li>Rotary compressors (centrifugal, axial)<\/li>\n <li>Industrial gas turbines with power up to 3 MW<\/li>\n <li>Electric motors of all types with flexible shaft coupling<\/li>\n <li>Rolling mills and rolling stands<\/li>\n <li>Fans and blowers (see note below)<\/li>\n <li>Conveyors, variable-speed couplings, turbo-fan engines<\/li>\n<\/ul>\n\n<div class=\"info-box\">\n <h4>Notes on Specific Equipment<\/h4>\n <p><strong>Steam\/gas turbines >40 MW<\/strong> at 1500\/1800\/3000\/3600 r\/min \u2192 use ISO 20816-2. <strong>Gas turbines >3 MW<\/strong> \u2192 use ISO 20816-4. <strong>Fans:<\/strong> Criteria generally apply only to fans >300 kW or on rigid foundations. For other fans, agree criteria between manufacturer and customer (see also ISO 14694).<\/p>\n<\/div>\n\n<h4>This Standard Does NOT Apply To:<\/h4>\n<ul>\n <li>Reciprocating machines \u2192 ISO 10816-6 \/ ISO 20816-8<\/li>\n <li>Rotodynamic pumps with built-in motors \u2192 ISO 10816-7<\/li>\n <li>Hydraulic power stations \u2192 ISO 20816-5<\/li>\n <li>Positive displacement compressors, submersible pumps<\/li>\n <li>Wind turbines \u2192 ISO 10816-21<\/li>\n<\/ul>\n\n<div class=\"crit-box\">\n <h4>Critical Limitation<\/h4>\n <p>Requirements apply <strong>only to vibration produced by the machine itself<\/strong>, not to externally induced vibration transmitted through foundations. Always verify and correct for background vibration.<\/p>\n<\/div>\n<\/section>\n\n<!-- CLASSIFICATION -->\n<section id=\"s-class\">\n<h2 class=\"section-title\">2. Machine Classification<\/h2>\n<p>Machine vibration condition is assessed depending on machine type, rated power or shaft height, and foundation rigidity.<\/p>\n\n<h3>Classification by Power \/ Shaft Height<\/h3>\n\n<h4>Group 1 \u2014 Large Machines<\/h4>\n<ul>\n <li>Power rating <strong>> 300 kW<\/strong>, OR electric machines with shaft height <strong>H > 315 mm<\/strong><\/li>\n <li>Typically equipped with journal (sleeve) bearings<\/li>\n <li>Operating speeds 120 to 30,000 r\/min<\/li>\n<\/ul>\n\n<h4>Group 2 \u2014 Medium Machines<\/h4>\n<ul>\n <li>Power rating <strong>15 \u2013 300 kW<\/strong>, OR electric machines with <strong>160 < H \u2264 315 mm<\/strong><\/li>\n <li>Typically equipped with rolling element bearings<\/li>\n <li>Operating speeds generally > 600 r\/min<\/li>\n<\/ul>\n\n<h3>Classification by Foundation Rigidity<\/h3>\n<p>A foundation is <strong>rigid<\/strong> if the lowest natural frequency of the machine-foundation system in the measurement direction exceeds the main excitation frequency by <strong>at least 25%<\/strong>. All others are <strong>flexible<\/strong>.<\/p>\n\n<div class=\"formula-box\">\n <strong>Rigid criterion:<\/strong> f<sub>n(machine+foundation)<\/sub> \u2265 1.25 \u00d7 f<sub>excitation<\/sub>\n<\/div>\n\n<div class=\"warn-box\">\n <h4>Direction-Dependent Classification<\/h4>\n <p>A foundation may be rigid in one direction and flexible in another. For example, rigid vertically but flexible horizontally. Evaluate each direction separately using appropriate limits.<\/p>\n<\/div>\n<\/section>\n\n<!-- ZONES -->\n<section id=\"s-zones\">\n<h2 class=\"section-title\">3. Understanding Zones A\u2013D<\/h2>\n<p>Four vibration condition zones are established for qualitative assessment and decision-making:<\/p>\n\n<div class=\"zone-cards\">\n <div class=\"zc zc-a\">\n <h4>Zone A \u2014 New \/ Excellent<\/h4>\n <p>Newly commissioned machines typically fall here. Represents optimal dynamic condition. Not all new machines achieve Zone A \u2014 striving below A\/B may yield minimal benefit at high cost.<\/p>\n <\/div>\n <div class=\"zc zc-b\">\n <h4>Zone B \u2014 Acceptable<\/h4>\n <p>Suitable for unrestricted long-term operation. Continue routine monitoring. This is the normal operating condition for well-maintained equipment.<\/p>\n <\/div>\n <div class=\"zc zc-c\">\n <h4>Zone C \u2014 Limited Operation<\/h4>\n <p>Not suitable for continuous long-term operation. Plan remedial action. May operate for a limited period until repair opportunity arises. Increase monitoring frequency.<\/p>\n <\/div>\n <div class=\"zc zc-d\">\n <h4>Zone D \u2014 Dangerous<\/h4>\n <p>Vibration severe enough to cause damage. Immediate action required: reduce vibration or stop the machine. Continued operation risks catastrophic failure.<\/p>\n <\/div>\n<\/div>\n<\/section>\n\n<!-- CRITERIA -->\n<section id=\"s-criteria\">\n<h2 class=\"section-title\">4. Evaluation Criteria<\/h2>\n\n<h3>Criterion I \u2014 Absolute Magnitude<\/h3>\n<p>The maximum measured broadband RMS vibration (velocity for housing, displacement p-p for shaft) is compared with zone boundary values for the given machine group and support type. This criterion protects against excessive dynamic loads on bearings, unacceptable radial clearance consumption, and excessive vibration transmitted to the foundation.<\/p>\n\n<h3>Criterion II \u2014 Change from Baseline<\/h3>\n<p>Even if vibration remains in Zone B, a significant change from the established baseline indicates developing problems and requires investigation.<\/p>\n\n<div class=\"crit-box\">\n <h4>The 25% Rule<\/h4>\n <p>A vibration change is considered <strong>significant<\/strong> if it exceeds <strong>25% of the B\/C boundary value<\/strong>, regardless of current absolute level. This applies to both increases and decreases.<\/p>\n <p><strong>Example:<\/strong> For Group 1 rigid foundation, B\/C = 4.5 mm\/s. A change > 1.125 mm\/s from baseline is significant and requires investigation.<\/p>\n<\/div>\n\n<div class=\"info-box\">\n <h4>Acceptance Criteria for New Machines<\/h4>\n <p>Zone boundaries are <strong>not<\/strong> acceptance criteria by default. Acceptance testing limits must be agreed between supplier and customer. Typical recommendation: new machine vibration should not exceed <strong>1.25 \u00d7 A\/B boundary<\/strong>.<\/p>\n<\/div>\n<\/section>\n\n<!-- MEASUREMENT -->\n<section id=\"s-meas\">\n<h2 class=\"section-title\">5. Measurement Best Practices<\/h2>\n\n<h3>Sensor Location<\/h3>\n<ul>\n <li>Mount on <strong>bearing housings or pedestals<\/strong> \u2014 not on thin-walled covers or flexible surfaces<\/li>\n <li>Use <strong>two mutually perpendicular radial directions<\/strong> at each bearing<\/li>\n <li>For horizontal machines, one direction is typically vertical<\/li>\n <li>Avoid locations with local resonances \u2014 compare readings at nearby points<\/li>\n <li>If direct access to bearing impossible, use a point with rigid mechanical connection<\/li>\n<\/ul>\n\n<h3>Operating Conditions<\/h3>\n<ul>\n <li>Measure in <strong>steady-state operation<\/strong> at nominal speed and load<\/li>\n <li>Allow rotor and bearings to reach <strong>thermal equilibrium<\/strong> (typically 30\u201360 min)<\/li>\n <li>For variable-speed\/load machines, measure at all characteristic operating points, use the maximum<\/li>\n <li>Document conditions: speed, load, temperatures, pressures<\/li>\n<\/ul>\n\n<h3>Frequency Range<\/h3>\n<div class=\"tw\">\n<table class=\"ct\">\n <thead><tr><th>Application<\/th><th>Lower Limit<\/th><th>Upper Limit<\/th><th>Notes<\/th><\/tr><\/thead>\n <tbody>\n <tr><td>Standard broadband<\/td><td>10 Hz<\/td><td>1000 Hz<\/td><td>Most industrial machinery (>600 r\/min)<\/td><\/tr>\n <tr><td>Low-speed (\u2264600 r\/min)<\/td><td>2 Hz<\/td><td>1000 Hz<\/td><td>Must capture 1\u00d7 running speed<\/td><\/tr>\n <tr><td>Shaft vibration<\/td><td>\u2014<\/td><td>\u2265 3.5 \u00d7 f<sub>max<\/sub><\/td><td>Per ISO 10817-1<\/td><\/tr>\n <tr><td>Diagnostics<\/td><td>0.2 \u00d7 f<sub>min<\/sub><\/td><td>2.5 \u00d7 f<sub>excit<\/sub><\/td><td>Extended, up to 10,000 Hz<\/td><\/tr>\n <\/tbody>\n<\/table>\n<\/div>\n\n<h3>Background Vibration<\/h3>\n<div class=\"crit-box\">\n <h4>25% Rule for Background<\/h4>\n <p>If stopped-machine vibration exceeds <strong>25% of operating vibration<\/strong> OR <strong>25% of Zone B\/C boundary<\/strong>, corrections are needed:<\/p>\n <div class=\"formula-box\" style=\"margin-top:10px;\">\n V<sub>machine<\/sub> = \u221a(V<sub>measured<\/sub>\u00b2 \u2212 V<sub>background<\/sub>\u00b2)\n <\/div>\n <p style=\"margin-top:8px;\">If background exceeds these thresholds, simple subtraction is invalid \u2014 investigate external sources.<\/p>\n<\/div>\n<\/section>\n\n<!-- HOUSING LIMITS -->\n<section id=\"s-housing\">\n<h2 class=\"section-title\">6. Housing Vibration Limits (Annex A)<\/h2>\n<p>The primary monitored parameter is <strong>RMS vibration velocity<\/strong>. Zone boundary values for Groups 1 and 2 are presented in Tables A.1 and A.2 above. Key notes:<\/p>\n<ul>\n <li>For machines with rotor speed <strong>below 600 r\/min<\/strong>, both velocity and displacement criteria apply. The frequency band extends to 2\u20131000 Hz.<\/li>\n <li><strong>Group 1 displacement<\/strong> is derived from velocity at reference frequency 12.5 Hz<\/li>\n <li><strong>Group 2 displacement<\/strong> is derived from velocity at reference frequency 10 Hz<\/li>\n <li>The <strong>worst-case zone<\/strong> (from velocity or displacement) governs<\/li>\n<\/ul>\n<\/section>\n\n<!-- SHAFT LIMITS -->\n<section id=\"s-shaft\">\n<h2 class=\"section-title\">7. Shaft Vibration Limits (Annex B)<\/h2>\n<p>For shaft relative vibration measured with proximity probes, zone boundaries are expressed as <strong>peak-to-peak displacement S(p-p)<\/strong> in \u03bcm, inversely proportional to \u221an:<\/p>\n\n<div class=\"formula-box\">\n <strong>A\/B:<\/strong> S(p-p) = 4800 \/ \u221an<br>\n <strong>B\/C:<\/strong> S(p-p) = 9000 \/ \u221an<br>\n <strong>C\/D:<\/strong> S(p-p) = 13200 \/ \u221an<br>\n <em style=\"font-size:14px;\">where n = max operating speed in r\/min, min 600 for calculation<\/em>\n<\/div>\n\n<div class=\"warn-box\">\n <h4>Bearing Clearance Limitation (Annex C)<\/h4>\n <p>For journal bearings, shaft vibration zone boundaries must be checked against actual bearing clearance. If formula-calculated limits exceed clearance, use clearance-based limits:<\/p>\n <ul>\n <li><strong>A\/B:<\/strong> 0.4 \u00d7 clearance<\/li>\n <li><strong>B\/C:<\/strong> 0.6 \u00d7 clearance<\/li>\n <li><strong>C\/D:<\/strong> 0.7 \u00d7 clearance<\/li>\n <\/ul>\n<\/div>\n<\/section>\n\n<!-- ALARMS -->\n<section id=\"s-alarms\">\n<h2 class=\"section-title\">8. WARNING & TRIP Alarm Levels<\/h2>\n\n<div class=\"formula-box\">\n <strong>WARNING<\/strong> = Baseline + 0.25 \u00d7 (B\/C boundary), typically \u2264 1.25 \u00d7 B\/C<br><br>\n <strong>TRIP<\/strong> = within Zone C or D, typically \u2264 1.25 \u00d7 (C\/D boundary)\n<\/div>\n\n<div class=\"tw\">\n<table class=\"ct\">\n <thead><tr><th>Level<\/th><th>Basis<\/th><th>Setting<\/th><th>Adjustable?<\/th><\/tr><\/thead>\n <tbody>\n <tr><td><strong>WARNING<\/strong><\/td><td>Machine-specific baseline<\/td><td>Baseline + 25% of B\/C<\/td><td>Yes \u2014 adjust with baseline changes<\/td><\/tr>\n <tr><td><strong>TRIP<\/strong><\/td><td>Mechanical integrity<\/td><td>Within Zone C\/D, \u2264 1.25 \u00d7 C\/D<\/td><td>No \u2014 same for similar machines<\/td><\/tr>\n <\/tbody>\n<\/table>\n<\/div>\n<\/section>\n\n<!-- TRANSIENT -->\n<section id=\"s-transient\">\n<h2 class=\"section-title\">9. Transient Operation<\/h2>\n<p>Zone boundaries apply to steady-state operation. During run-up, coast-down, or passage through critical speeds, higher vibration is expected.<\/p>\n\n<div class=\"tw\">\n<table class=\"ct\">\n <thead><tr><th>Speed % of Rated<\/th><th>Housing Limit<\/th><th>Shaft Limit<\/th><th>Notes<\/th><\/tr><\/thead>\n <tbody>\n <tr><td>< 20%<\/td><td>See note<\/td><td>1.5 \u00d7 C\/D<\/td><td>Displacement may dominate<\/td><\/tr>\n <tr><td>20% \u2013 90%<\/td><td>1.0 \u00d7 C\/D<\/td><td>1.5 \u00d7 C\/D<\/td><td>Critical speed passage allowed<\/td><\/tr>\n <tr><td>> 90%<\/td><td>1.0 \u00d7 C\/D<\/td><td>1.0 \u00d7 C\/D<\/td><td>Approaching steady-state<\/td><\/tr>\n <\/tbody>\n<\/table>\n<\/div>\n<p>If vibration remains high after reaching operating speed, it indicates a <strong>persistent fault<\/strong>, not a transient resonance.<\/p>\n<\/section>\n\n<!-- PHYSICS -->\n<section id=\"s-physics\">\n<h2 class=\"section-title\">10. Physics & Signal Processing<\/h2>\n\n<h3>Displacement\u2013Velocity\u2013Acceleration<\/h3>\n<p>For sinusoidal vibration at frequency f (Hz):<\/p>\n<div class=\"formula-box\">\n <strong>Velocity:<\/strong> V<sub>peak<\/sub> = 2\u03c0f \u00d7 D<sub>peak<\/sub><br>\n <strong>Acceleration:<\/strong> A<sub>peak<\/sub> = (2\u03c0f)\u00b2 \u00d7 D<sub>peak<\/sub> = 2\u03c0f \u00d7 V<sub>peak<\/sub>\n<\/div>\n<ul>\n <li>At <strong>low frequencies<\/strong> (<10 Hz): displacement is the critical parameter<\/li>\n <li>At <strong>mid frequencies<\/strong> (10\u20131000 Hz): velocity correlates with energy \u2014 frequency-independent<\/li>\n <li>At <strong>high frequencies<\/strong> (>1000 Hz): acceleration becomes dominant<\/li>\n<\/ul>\n\n<h3>RMS vs Peak<\/h3>\n<div class=\"formula-box\">\n V<sub>RMS<\/sub> = V<sub>peak<\/sub> \/ \u221a2 \u2248 0.707 \u00d7 V<sub>peak<\/sub><br>\n V<sub>p-p<\/sub> = 2 \u00d7 V<sub>peak<\/sub> \u2248 2.828 \u00d7 V<sub>RMS<\/sub>\n<\/div>\n\n<h3>Broadband RMS (Overall)<\/h3>\n<div class=\"formula-box\">\n V<sub>RMS(total)<\/sub> = \u221a(V\u00b2<sub>1<\/sub> + V\u00b2<sub>2<\/sub> + ... + V\u00b2<sub>n<\/sub>)\n<\/div>\n<p>This \"Overall\" value is what vibration analyzers display and what ISO 20816-3 uses for zone evaluation.<\/p>\n\n<h3>Low-Speed Problem (Annex D)<\/h3>\n<p>At constant velocity of 4.5 mm\/s, displacement grows dramatically with decreasing speed:<\/p>\n<div class=\"tw\">\n<table class=\"ct\">\n <thead><tr><th>Speed (rpm)<\/th><th>Freq (Hz)<\/th><th>Velocity (mm\/s)<\/th><th>Displacement (\u03bcm peak)<\/th><\/tr><\/thead>\n <tbody>\n <tr><td>3600<\/td><td>60<\/td><td>4.5<\/td><td>12<\/td><\/tr>\n <tr><td>1800<\/td><td>30<\/td><td>4.5<\/td><td>24<\/td><\/tr>\n <tr><td>600<\/td><td>10<\/td><td>4.5<\/td><td>72<\/td><\/tr>\n <tr><td>120<\/td><td>2<\/td><td>4.5<\/td><td>358<\/td><\/tr>\n <\/tbody>\n<\/table>\n<\/div>\n<p>This is why the standard requires <strong>both velocity and displacement<\/strong> criteria for machines \u2264600 r\/min.<\/p>\n<\/section>\n\n<!-- BALANCING -->\n<section id=\"s-balancing\">\n<h2 class=\"section-title\">11. Influence Coefficient Balancing<\/h2>\n<p>When unbalance is diagnosed (high 1\u00d7 vibration, stable phase), the <strong>influence coefficient method<\/strong> calculates precise correction weights:<\/p>\n\n<div class=\"formula-box\">\n <strong>Influence coefficient:<\/strong> \u03b1 = (V<sub>trial<\/sub> \u2212 V<sub>initial<\/sub>) \/ M<sub>trial<\/sub><br><br>\n <strong>Correction mass:<\/strong> M<sub>corr<\/sub> = \u2212V<sub>initial<\/sub> \/ \u03b1\n<\/div>\n\n<h4>Single-Plane Procedure (3 runs)<\/h4>\n<ol>\n <li><strong>Initial run:<\/strong> Measure A\u2080 = 6.2 mm\/s at \u03c6\u2080 = 45\u00b0<\/li>\n <li><strong>Trial weight:<\/strong> Add 20 g at 0\u00b0. Measure A\u2081 = 4.1 mm\/s at \u03c6\u2081 = 110\u00b0<\/li>\n <li><strong>Calculate:<\/strong> Software computes correction = 28.5 g at 215\u00b0<\/li>\n <li><strong>Apply & verify:<\/strong> Remove trial, add 28.5 g at 215\u00b0. Final: 1.1 mm\/s \u2192 Zone A<\/li>\n<\/ol>\n<p>The Balanset-1A performs all vector math automatically, guiding the technician through each step.<\/p>\n<\/section>\n\n<!-- CASE STUDIES -->\n<section id=\"s-cases\">\n<h2 class=\"section-title\">12. Case Studies<\/h2>\n\n<div class=\"case\">\n <div class=\"case-tag\">Case Study 1<\/div>\n <h4>Misdiagnosis Avoided Through Dual Measurement<\/h4>\n <p><strong>Machine:<\/strong> 5 MW steam turbine, 3000 rpm, journal bearings.<\/p>\n <p><strong>Situation:<\/strong> Housing vibration = 3.0 mm\/s (Zone B). But shaft vibration = 180 \u03bcm p-p. Annex B limit B\/C = 164 \u03bcm \u2192 Shaft in Zone C!<\/p>\n <p><strong>Root cause:<\/strong> Oil film instability (oil whirl). Heavy pedestal damped housing motion. Relying only on housing measurement would have missed the condition.<\/p>\n <p><strong>Action:<\/strong> Adjusted oil supply pressure, re-shimmed bearing. Shaft vibration reduced to 90 \u03bcm (Zone A).<\/p>\n <span class=\"case-result res-good\">\u2713 Zone A achieved \u2014 oil whirl eliminated<\/span>\n<\/div>\n\n<div class=\"case\">\n <div class=\"case-tag\">Case Study 2<\/div>\n <h4>Balancing Saves a Critical Fan<\/h4>\n <p><strong>Machine:<\/strong> 200 kW induced draft fan, 980 rpm, flexible coupling.<\/p>\n <p><strong>Initial:<\/strong> Vibration = 7.8 mm\/s (Zone D). Plant considering emergency shutdown ($50,000, 3-day outage).<\/p>\n <p><strong>Diagnosis:<\/strong> FFT shows 1\u00d7 = 7.5 mm\/s. Phase stable \u2192 Unbalance, not bearing damage.<\/p>\n <p><strong>Action:<\/strong> Two-plane balancing with Balanset-1A, 4 hours on-site. Final = 1.6 mm\/s (Zone A).<\/p>\n <span class=\"case-result res-good\">\u2713 $50,000 saved \u2014 avoided unnecessary shutdown<\/span>\n<\/div>\n\n<div class=\"case\">\n <div class=\"case-tag\">Case Study 3<\/div>\n <h4>Zone D Pump \u2014 Balancing Won't Help<\/h4>\n <p><strong>Machine:<\/strong> 200 kW feed pump, rigid foundation. RMS = 5.0 mm\/s \u2192 Zone D.<\/p>\n <p><strong>Diagnosis:<\/strong> FFT shows harmonic forest and high noise floor. 1\u00d7 peak low relative to total. Not unbalance.<\/p>\n <p><strong>Root cause:<\/strong> Bearing degradation + cavitation. Required mechanical overhaul.<\/p>\n <span class=\"case-result res-bad\">\u2717 Immediate shutdown required \u2014 mechanical failure<\/span>\n<\/div>\n<\/section>\n\n<!-- MISTAKES -->\n<section id=\"s-mistakes\">\n<h2 class=\"section-title\">13. Common Mistakes<\/h2>\n\n<div class=\"crit-box\">\n <h4>Critical Errors to Avoid<\/h4>\n\n <p><strong>1. Wrong classification.<\/strong> A 250 kW motor with H=280 mm is Group 2 (not Group 1). Using Group 1 limits (more lenient) permits excessive vibration.<\/p>\n\n <p><strong>2. Wrong foundation type.<\/strong> Not all concrete foundations are \"rigid.\" A turbogenerator on concrete may be flexible if system natural frequency is near running speed. Verify by calculation or impact testing.<\/p>\n\n <p><strong>3. Ignoring background vibration.<\/strong> A pump reading 3.5 mm\/s with 2.0 mm\/s from an adjacent compressor through the floor: actual pump contribution is only ~1.5 mm\/s. Always measure with machine stopped.<\/p>\n\n <p><strong>4. Peak instead of RMS.<\/strong> ISO 20816-3 requires RMS. Peak \u2248 1.414 \u00d7 RMS. Using peak values directly overestimates severity by ~40%.<\/p>\n\n <p><strong>5. Neglecting Criterion II.<\/strong> Fan jumps from 1.5 to 2.5 mm\/s (both Zone B). Change = 1.0 mm\/s vs threshold 1.125 mm\/s (25% of B\/C=4.5). Close to threshold \u2014 investigate!<\/p>\n\n <p><strong>6. Wrong frequency range.<\/strong> A 400 rpm mill with 10\u20131000 Hz filter: running frequency = 6.67 Hz is below the filter! Use 2\u20131000 Hz for machines \u2264600 r\/min.<\/p>\n\n <p><strong>7. Measuring on thin walls.<\/strong> Accelerometer on fan casing sheet metal gives 10\u00d7 higher readings than actual bearing vibration. Always mount on bearing cap or pedestal.<\/p>\n<\/div>\n<\/section>\n\n<!-- WORKFLOW -->\n<section id=\"s-workflow\">\n<h2 class=\"section-title\">14. Complete Assessment Workflow<\/h2>\n\n<div class=\"summary-box\">\n <h4>Step-by-Step Procedure<\/h4>\n <ol class=\"steps\">\n <li><strong>Identify machine:<\/strong> Record type, model, rated power, speed range<\/li>\n <li><strong>Classify:<\/strong> Determine Group (1 or 2) from power rating or shaft height H<\/li>\n <li><strong>Assess foundation:<\/strong> Measure\/calculate f<sub>n<\/sub> of machine-foundation system vs f<sub>run<\/sub><\/li>\n <li><strong>Select zone boundaries<\/strong> from standard for group + foundation type<\/li>\n <li><strong>Set up instruments:<\/strong> Mount sensors on bearing housings, configure frequency range<\/li>\n <li><strong>Background check:<\/strong> Measure vibration with machine stopped<\/li>\n <li><strong>Operating measurement:<\/strong> Reach thermal equilibrium, steady-state, measure RMS velocity<\/li>\n <li><strong>Background correction:<\/strong> Apply energy subtraction if threshold exceeded<\/li>\n <li><strong>Zone classification (Criterion I):<\/strong> Compare maximum RMS to boundaries<\/li>\n <li><strong>Trend analysis (Criterion II):<\/strong> Calculate change from baseline, check 25% rule<\/li>\n <li><strong>Spectral diagnosis:<\/strong> If needed, use FFT to identify fault type<\/li>\n <li><strong>Corrective action:<\/strong> Zone A \u2192 baseline; B \u2192 monitor; C \u2192 plan repair; D \u2192 immediate action<\/li>\n <li><strong>Balance if unbalance diagnosed:<\/strong> Use Balanset-1A influence coefficient method<\/li>\n <li><strong>Document:<\/strong> Report with before\/after spectra, zone classification, actions taken<\/li>\n <\/ol>\n<\/div>\n<\/section>\n\n<!-- PRODUCT BOX -->\n<div class=\"product-box\">\n <h3>\ud83d\udd27 Balanset-1A \u2014 Portable Vibration Analyzer & Field Balancer<\/h3>\n <p>The <strong>Balanset-1A<\/strong> is a precision instrument that directly supports ISO 20816-3 requirements for vibration measurement and assessment:<\/p>\n <ul>\n <li><strong>Vibration measurement:<\/strong> Velocity (mm\/s RMS), displacement, acceleration \u2014 all ISO 20816-3 parameters<\/li>\n <li><strong>Frequency range:<\/strong> 5 Hz \u2013 550 Hz (standard), expandable \u2014 covers 2\u20131000 Hz requirement<\/li>\n <li><strong>Single-plane and two-plane balancing:<\/strong> Reduce vibration to Zone A\/B levels<\/li>\n <li><strong>Phase measurement:<\/strong> \u00b11\u00b0 accuracy for balancing and vector analysis<\/li>\n <li><strong>RPM range:<\/strong> 150 to 60,000 rpm \u2014 fully covers ISO 20816-3 scope<\/li>\n <li><strong>FFT spectrum:<\/strong> Identify fault types (1\u00d7, 2\u00d7, harmonics, bearing defects)<\/li>\n <li><strong>Report generation:<\/strong> Document measurements for compliance records<\/li>\n <\/ul>\n <a href=\"https:\/\/vibromera.eu\/product\/balanset-1\/\" class=\"product-link\" target=\"_blank\" rel=\"noopener\">Learn More About Balanset-1A \u2192<\/a>\n<\/div>\n\n<!-- REFERENCE STANDARDS -->\n<section id=\"s-standards\">\n<h2 class=\"section-title\">15. Reference Standards<\/h2>\n\n<h3>Normative References<\/h3>\n<div class=\"tw\">\n<table class=\"ct\">\n <thead><tr><th>Standard<\/th><th>Title<\/th><\/tr><\/thead>\n <tbody>\n <tr><td><strong>ISO 2041<\/strong><\/td><td>Mechanical vibration, shock and condition monitoring \u2014 Vocabulary<\/td><\/tr>\n <tr><td><strong>ISO 2954<\/strong><\/td><td>Requirements for instruments for measuring vibration severity<\/td><\/tr>\n <tr><td><strong>ISO 10817-1<\/strong><\/td><td>Rotating shaft vibration measuring systems \u2014 Relative and absolute sensing<\/td><\/tr>\n <tr><td><strong>ISO 20816-1:2016<\/strong><\/td><td>Mechanical vibration \u2014 Measurement and evaluation \u2014 General guidelines<\/td><\/tr>\n <\/tbody>\n<\/table>\n<\/div>\n\n<h3>ISO 20816 Series<\/h3>\n<div class=\"tw\">\n<table class=\"ct\">\n <thead><tr><th>Standard<\/th><th>Scope<\/th><th>Status<\/th><\/tr><\/thead>\n <tbody>\n <tr><td>ISO 20816-1:2016<\/td><td>General guidelines<\/td><td>Published<\/td><\/tr>\n <tr><td>ISO 20816-2:2017<\/td><td>Steam\/gas turbines >40 MW, 1500\u20133600 r\/min<\/td><td>Published<\/td><\/tr>\n <tr><td><strong>ISO 20816-3:2022<\/strong><\/td><td>Industrial machinery >15 kW, 120\u201330,000 r\/min<\/td><td>Published (this document)<\/td><\/tr>\n <tr><td>ISO 20816-4:2018<\/td><td>Gas turbine driven sets<\/td><td>Published<\/td><\/tr>\n <tr><td>ISO 20816-5:2018<\/td><td>Hydraulic power plants<\/td><td>Published<\/td><\/tr>\n <tr><td>ISO 20816-8:2018<\/td><td>Reciprocating compressor systems<\/td><td>Published<\/td><\/tr>\n <tr><td>ISO 20816-9<\/td><td>Gear units<\/td><td>In development<\/td><\/tr>\n <\/tbody>\n<\/table>\n<\/div>\n\n<h3>Complementary Standards<\/h3>\n<div class=\"tw\">\n<table class=\"ct\">\n <thead><tr><th>Standard<\/th><th>Title<\/th><th>Relevance<\/th><\/tr><\/thead>\n <tbody>\n <tr><td>ISO 21940-11<\/td><td>Rotor balancing \u2014 Procedures and tolerances<\/td><td>Balance quality grades G0.4\u2013G4000<\/td><\/tr>\n <tr><td>ISO 13373-1\/2\/3<\/td><td>Vibration condition monitoring & diagnostics<\/td><td>FFT, analysis, fault signatures<\/td><\/tr>\n <tr><td>ISO 18436-2<\/td><td>Vibration analyst certification (Cat I\u2013IV)<\/td><td>Personnel competence<\/td><\/tr>\n <tr><td>ISO 14694<\/td><td>Industrial fans \u2014 Balance quality and vibration<\/td><td>Fan-specific limits<\/td><\/tr>\n <\/tbody>\n<\/table>\n<\/div>\n\n<h3>GOST Correspondence (Annex DA)<\/h3>\n<div class=\"tw\">\n<table class=\"ct\">\n <thead><tr><th>ISO Standard<\/th><th>Correspondence<\/th><th>GOST Equivalent<\/th><\/tr><\/thead>\n <tbody>\n <tr><td>ISO 2041<\/td><td>IDT<\/td><td>GOST R ISO 2041-2012<\/td><\/tr>\n <tr><td>ISO 2954<\/td><td>IDT<\/td><td>GOST ISO 2954-2014<\/td><\/tr>\n <tr><td>ISO 10817-1<\/td><td>IDT<\/td><td>GOST ISO 10817-1-2002<\/td><\/tr>\n <tr><td>ISO 20816-1:2016<\/td><td>IDT<\/td><td>GOST R ISO 20816-1-2021<\/td><\/tr>\n <\/tbody>\n<\/table>\n<\/div>\n<p><strong>IDT<\/strong> = Identical standards.<\/p>\n\n<h3>Historical Context<\/h3>\n<p>ISO 20816-3:2022 replaces <strong>ISO 10816-3:2009<\/strong> (housing vibration) and <strong>ISO 7919-3:2009<\/strong> (shaft vibration), integrating both into a unified evaluation framework. The pioneer work by Rathbone (1939) established the foundation for using velocity as the primary vibration criterion.<\/p>\n<\/section>\n\n<!-- FAQ -->\n<section id=\"s-faq\">\n<h2 class=\"section-title\">16. Frequently Asked Questions<\/h2>\n\n<div class=\"faq-item\">\n <div class=\"faq-q\" role=\"button\" tabindex=\"0\">What is the difference between ISO 20816-3 and the old ISO 10816-3?<\/div>\n <div class=\"faq-a\">\n <p>ISO 20816-3:2022 supersedes and replaces both ISO 10816-3:2009 and ISO 7919-3:2009. Main differences: integration of housing and shaft vibration criteria into one document, updated zone boundaries based on more recent operational experience, clearer guidance on foundation classification, and expanded guidance on low-speed machines. If your specifications reference ISO 10816-3, you should transition to ISO 20816-3.<\/p>\n <\/div>\n<\/div>\n\n<div class=\"faq-item\">\n <div class=\"faq-q\" role=\"button\" tabindex=\"0\">Should I use velocity or displacement for assessment?<\/div>\n <div class=\"faq-a\">\n <p>For most machines above 600 r\/min, <strong>velocity<\/strong> is the primary criterion. Use displacement additionally when: machine speed is \u2264600 r\/min (displacement may be the limiting factor), significant low-frequency components are present, or measuring shaft relative vibration (always use peak-to-peak displacement). If in doubt, check against both criteria \u2014 the worst-case zone governs.<\/p>\n <\/div>\n<\/div>\n\n<div class=\"faq-item\">\n <div class=\"faq-q\" role=\"button\" tabindex=\"0\">How do I determine if my foundation is rigid or flexible?<\/div>\n <div class=\"faq-a\">\n <p>The most accurate method is to measure or calculate the lowest natural frequency of the machine-foundation system. Methods: impact test (bump test), operational modal analysis, or FEA calculation. Quick estimate: if the machine visibly moves on its mounts during startup\/shutdown, it's likely flexible. If f<sub>n<\/sub> \u2265 1.25 \u00d7 running frequency \u2192 Rigid; otherwise \u2192 Flexible. Note: a foundation may be rigid vertically but flexible horizontally.<\/p>\n <\/div>\n<\/div>\n\n<div class=\"faq-item\">\n <div class=\"faq-q\" role=\"button\" tabindex=\"0\">What if my machine is in Zone C \u2014 can I keep running?<\/div>\n <div class=\"faq-a\">\n <p>Zone C means <strong>not suitable for continuous long-term operation<\/strong>, but doesn't require immediate shutdown. You should: investigate the cause, plan remedial action, monitor frequently for rapid changes, set a deadline for repair (next scheduled outage), and ensure vibration doesn't approach Zone D. The decision to continue depends on machine criticality and consequences of failure.<\/p>\n <\/div>\n<\/div>\n\n<div class=\"faq-item\">\n <div class=\"faq-q\" role=\"button\" tabindex=\"0\">How can balancing help meet ISO 20816-3 limits?<\/div>\n <div class=\"faq-a\">\n <p><strong>Unbalance<\/strong> is the most common cause of excessive vibration at running speed (1\u00d7). Field balancing with the Balanset-1A can reduce vibration from Zone C\/D back to Zone A\/B. The instrument measures vibration velocity to ISO 20816-3 requirements, calculates correction masses, verifies results, and documents before\/after levels for compliance records.<\/p>\n <\/div>\n<\/div>\n\n<div class=\"faq-item\">\n <div class=\"faq-q\" role=\"button\" tabindex=\"0\">What causes vibration to increase suddenly?<\/div>\n <div class=\"faq-a\">\n <p>Sudden increases (triggering Criterion II) may indicate: loss of balance weight, bearing damage, coupling failure, structural looseness (foundation bolt loosening), rotor rub, or process changes (cavitation, surge). Any change >25% of B\/C boundary warrants investigation, even if absolute level is still acceptable.<\/p>\n <\/div>\n<\/div>\n\n<div class=\"faq-item\">\n <div class=\"faq-q\" role=\"button\" tabindex=\"0\">What about housing vs shaft disagreement?<\/div>\n <div class=\"faq-a\">\n <p>If housing vibration indicates Zone B but shaft vibration indicates Zone C, classify the machine as <strong>Zone C<\/strong> (the more restrictive assessment governs). There is no simple method to calculate housing vibration from shaft vibration or vice versa. Always use the worst-case zone from dual measurements.<\/p>\n <\/div>\n<\/div>\n<\/section>\n\n<\/div><!-- .page-wrap -->\n\n<script>\n(function(){\n 'use strict';\n\n var LIMITS = {\n group1: {\n rigid: {ab_v:2.3, bc_v:4.5, cd_v:7.1, ab_d:29, bc_d:57, cd_d:90},\n flexible: {ab_v:3.5, bc_v:7.1, cd_v:11.0, ab_d:45, bc_d:90, cd_d:140}\n },\n group2: {\n rigid: {ab_v:1.4, bc_v:2.8, cd_v:4.5, ab_d:22, bc_d:45, cd_d:71},\n flexible: {ab_v:2.3, bc_v:4.5, cd_v:7.1, ab_d:37, bc_d:71, cd_d:113}\n }\n };\n\n var form = document.getElementById('calcForm');\n var results = document.getElementById('results');\n var mtype = document.getElementById('c-mtype');\n var bInputs = document.getElementById('bearingInputs');\n var sInputs = document.getElementById('shaftInputs');\n\n mtype.addEventListener('change', function(){\n var isShaft = mtype.value === 'shaft';\n bInputs.classList.toggle('hidden', isShaft);\n sInputs.classList.toggle('hidden', !isShaft);\n results.classList.remove('visible');\n });\n\n document.getElementById('resetBtn').addEventListener('click', function(){\n form.reset();\n results.classList.remove('visible');\n bInputs.classList.remove('hidden');\n sInputs.classList.add('hidden');\n });\n\n form.addEventListener('submit', function(e){\n e.preventDefault();\n calc();\n });\n\n function num(id){\n var v = parseFloat(document.getElementById(id).value);\n return isFinite(v) ? v : NaN;\n }\n\n function calc(){\n var power = num('c-power');\n var pu = document.getElementById('c-power-unit').value;\n var speed = num('c-speed');\n var height = num('c-height') || 0;\n var found = document.getElementById('c-foundation').value;\n var mt = mtype.value;\n\n if(pu==='MW') power*=1000;\n if(pu==='hp') power*=0.7457;\n\n var group = (power>300 || height>315) ? 'group1' : 'group2';\n var ft = found==='unknown' ? 'flexible' : found;\n var lim = LIMITS[group][ft];\n\n document.getElementById('r-group').textContent =\n group==='group1' ? 'Group 1 (Large: >300 kW or H>315 mm)' : 'Group 2 (Medium: 15\u2013300 kW)';\n document.getElementById('r-found').textContent = ft.charAt(0).toUpperCase()+ft.slice(1)+(found==='unknown'?' (conservative)':'');\n\n document.getElementById('r-ab-v').textContent = lim.ab_v.toFixed(1);\n document.getElementById('r-bc-v').textContent = lim.bc_v.toFixed(1);\n document.getElementById('r-cd-v').textContent = lim.cd_v.toFixed(1);\n document.getElementById('r-ab-d').textContent = lim.ab_d;\n document.getElementById('r-bc-d').textContent = lim.bc_d;\n document.getElementById('r-cd-d').textContent = lim.cd_d;\n\n var zone, warnings=[];\n\n if(mt==='bearing'){\n var vel = num('c-vel');\n if(!isFinite(vel)||vel<0){\n alert('Enter measured velocity (mm\/s RMS).');\n return;\n }\n document.getElementById('r-val').textContent = vel.toFixed(2)+' mm\/s RMS';\n\n if(vel<=lim.ab_v) zone='A';\n else if(vel<=lim.bc_v) zone='B';\n else if(vel<=lim.cd_v) zone='C';\n else zone='D';\n\n var disp = num('c-disp-b');\n if(isFinite(disp)&&disp>=0){\n var zd;\n if(disp<=lim.ab_d) zd='A';\n else if(disp<=lim.bc_d) zd='B';\n else if(disp<=lim.cd_d) zd='C';\n else zd='D';\n if(zd>zone) zone=zd;\n } else if(speed<=600){\n warnings.push('Low speed (\u2264600 r\/min): velocity-only assessment may be incomplete. Measure displacement too.');\n }\n document.getElementById('r-shaft-table').classList.add('hidden');\n } else {\n var sd = num('c-shaft-disp');\n if(!isFinite(sd)||sd<0){\n alert('Enter shaft displacement S(p-p) in \u03bcm.');\n return;\n }\n document.getElementById('r-val').textContent = sd.toFixed(1)+' \u03bcm p-p';\n\n var sqN = Math.sqrt(Math.max(speed,600));\n var sAB=4800\/sqN, sBC=9000\/sqN, sCD=13200\/sqN;\n document.getElementById('r-s-ab').textContent = sAB.toFixed(1);\n document.getElementById('r-s-bc').textContent = sBC.toFixed(1);\n document.getElementById('r-s-cd').textContent = sCD.toFixed(1);\n document.getElementById('r-shaft-table').classList.remove('hidden');\n\n if(sd<=sAB) zone='A';\n else if(sd<=sBC) zone='B';\n else if(sd<=sCD) zone='C';\n else zone='D';\n\n var cl = num('c-clearance');\n if(isFinite(cl)&&cl>0&&sd>cl){\n warnings.push('S(p-p) exceeds bearing diametral clearance \u2014 verify operating permissibility.');\n }\n }\n\n var badge = document.getElementById('r-zone-badge');\n badge.className = 'zone-badge zone-badge-'+zone.toLowerCase();\n document.getElementById('r-zone-letter').textContent = zone;\n\n var rec = {\n A:'Excellent condition. Typical of newly commissioned or recently serviced machines. Record as baseline for trending.',\n B:'Acceptable for unrestricted long-term operation. Continue monitoring. Watch for changes relative to baseline.',\n C:'Not suitable for continuous long-term operation. Investigate cause (unbalance, misalignment, looseness, bearings, process). Plan corrective action. Increase monitoring frequency.',\n D:'Severe vibration level. Immediate action required: reduce vibration or remove machine from service. Do not operate extended periods.'\n }[zone];\n if(warnings.length) rec += ' \u26a0 '+warnings.join(' ');\n document.getElementById('r-rec').textContent = rec;\n\n results.classList.add('visible');\n results.scrollIntoView({behavior:'smooth',block:'nearest'});\n }\n\n \/\/ FAQ accordion\n document.querySelectorAll('.faq-item').forEach(function(item){\n var q = item.querySelector('.faq-q');\n q.addEventListener('click',function(){ toggle(item); });\n q.addEventListener('keydown',function(e){\n if(e.key==='Enter'||e.key===' '){ e.preventDefault(); toggle(item); }\n });\n });\n function toggle(item){\n var open = item.classList.contains('open');\n document.querySelectorAll('.faq-item').forEach(function(f){ f.classList.remove('open'); });\n if(!open) item.classList.add('open');\n }\n})();\n<\/script>\n\n<\/body>\n<\/html><\/div><\/div><\/div><\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>A detailed look at ISO 20816-3, the current standard specifying vibration limits for industrial machines, superseding ISO 10816-3.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"ai_generated_summary":"","footnotes":""},"categories":[109,112],"tags":[],"class_list":["post-13","glossary","type-glossary","status-publish","hentry","category-glossary","category-iso-standards"],"_links":{"self":[{"href":"https:\/\/vibromera.eu\/bn\/wp-json\/wp\/v2\/glossary\/13","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vibromera.eu\/bn\/wp-json\/wp\/v2\/glossary"}],"about":[{"href":"https:\/\/vibromera.eu\/bn\/wp-json\/wp\/v2\/types\/glossary"}],"version-history":[{"count":13,"href":"https:\/\/vibromera.eu\/bn\/wp-json\/wp\/v2\/glossary\/13\/revisions"}],"predecessor-version":[{"id":101735,"href":"https:\/\/vibromera.eu\/bn\/wp-json\/wp\/v2\/glossary\/13\/revisions\/101735"}],"wp:attachment":[{"href":"https:\/\/vibromera.eu\/bn\/wp-json\/wp\/v2\/media?parent=13"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vibromera.eu\/bn\/wp-json\/wp\/v2\/categories?post=13"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vibromera.eu\/bn\/wp-json\/wp\/v2\/tags?post=13"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}