{"id":259,"date":"2025-10-31T00:25:51","date_gmt":"2025-10-31T00:25:51","guid":{"rendered":"https:\/\/vibromera.eu\/glossary\/sub-synchronous\/"},"modified":"2026-05-23T22:39:45","modified_gmt":"2026-05-23T22:39:45","slug":"sub-synchronous","status":"publish","type":"glossary","link":"https:\/\/vibromera.eu\/ta\/glossary\/sub-synchronous\/","title":{"rendered":"Sub-Synchronous and Synchronous Vibration Explained"},"content":{"rendered":"<h1>Sub-Synchronous and Synchronous Vibration Explained<\/h1>\n\t\t<section class=\"woocommerce hestia-shop products is-shortcode\" id=\"products\" data-sorder=\"hestia_shop\" >\n\t\t\t\t\t\t<div class=\"\">\n\t\t\t\t\t\t<div class=\"hestia-shop-content\">\n\t\t\t<div class=\"row\" data-aos=\"fade-up\" >\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\/ta\/product\/balanset-1\/\" 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\/ta\/product\/balanset-1\/\" title=\"Portable balancer &amp; Vibration analyzer Balanset-1A\">\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\/09\/77-e1693745667801-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Balanset-1A \u0bae\u0bc1\u0bb4\u0bc1\u0bae\u0bc8\u0baf\u0bbe\u0ba9 \u0b95\u0bbf\u0b9f\u0bcd \u0b9a\u0bc1\u0bae\u0bc8\u0baf\u0bc8 \u0b8e\u0b9f\u0bc8 \u0bae\u0bb1\u0bcd\u0bb1\u0bc1\u0bae\u0bcd \u0b85\u0ba4\u0bbf\u0bb0\u0bcd\u0bb5\u0bc1 \u0baa\u0b95\u0bc1\u0baa\u0bcd\u0baa\u0bbe\u0baf\u0bcd\u0bb5\u0bbf\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/09\/77-e1693745667801-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/09\/77-e1693745667801-18x12.webp 18w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/09\/77-e1693745667801-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/09\/77-e1693745667801-272x182.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\/ta\/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\/ta\/product\/balanset-1\/\" title=\"Portable balancer &amp; Vibration analyzer Balanset-1A\">Portable balancer &amp; Vibration analyzer Balanset-1A<\/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\">\u20ac<\/span>1,975.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?add-to-cart=986\" data-quantity=\"1\" data-product_id=\"986\" data-product_sku=\"BS-1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"Add to cart\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Add to cart\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?add-to-cart=986\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_986\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"986\" data-product_sku=\"BS-1\" aria-label=\"Add to cart: \u201cPortable balancer &amp; Vibration analyzer Balanset-1A\u201d\" rel=\"nofollow\" data-success_message=\"\u201cPortable balancer &amp; Vibration analyzer Balanset-1A\u201d has been added to your cart\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Add to cart<\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_986\" 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\/ta\/product\/vibration-sensor\/\" 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\/ta\/product\/vibration-sensor\/\" title=\"Vibration sensor\">\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-3-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Balanset-1A \u0b85\u0ba4\u0bbf\u0bb0\u0bcd\u0bb5\u0bc1 \u0b9a\u0bc6\u0ba9\u0bcd\u0b9a\u0bb0\u0bcd \u0ba8\u0bc6\u0bb0\u0bc1\u0b95\u0bcd\u0b95\u0bae\u0bbe\u0ba9 \u0baa\u0bbe\u0bb0\u0bcd\u0bb5\u0bc8\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-600x400.webp 600w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-300x200.webp 300w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-768x512.webp 768w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-1024x682.webp 1024w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-272x182.webp 272w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3.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\/ta\/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\/ta\/product\/vibration-sensor\/\" title=\"Vibration sensor\">Vibration sensor<\/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\">\u20ac<\/span>90.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?add-to-cart=1820\" data-quantity=\"1\" data-product_id=\"1820\" data-product_sku=\"VS-1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"Add to cart\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Add to cart\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?add-to-cart=1820\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_1820\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"1820\" data-product_sku=\"VS-1\" aria-label=\"Add to cart: \u201cVibration sensor\u201d\" rel=\"nofollow\" data-success_message=\"\u201cVibration sensor\u201d has been added to your cart\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Add to cart<\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_1820\" 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\/ta\/product\/optical-sensor-for-balanset-and-arbalance\/\" 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\/ta\/product\/optical-sensor-for-balanset-and-arbalance\/\" title=\"Optical Sensor (Laser Tachometer)\">\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\/ZKqzGXSCCBU-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Optical Sensor (Laser Tachometer)\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-300x200.webp 300w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-1024x682.webp 1024w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-768x512.webp 768w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-1536x1023.webp 1536w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-18x12.webp 18w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-460x306.webp 460w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-600x400.webp 600w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-272x182.webp 272w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU.webp 1600w\" 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\/ta\/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\/ta\/product\/optical-sensor-for-balanset-and-arbalance\/\" title=\"Optical Sensor (Laser Tachometer)\">Optical Sensor (Laser Tachometer)<\/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\">\u20ac<\/span>124.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?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=\"Add to cart\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Add to cart\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?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=\"Add to cart: \u201cOptical Sensor (Laser Tachometer)\u201d\" rel=\"nofollow\" data-success_message=\"\u201cOptical Sensor (Laser Tachometer)\u201d has been added to your cart\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Add to cart<\/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\/ta\/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\/ta\/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 \u0b9a\u0bc1\u0bae\u0bc8 \u0b9a\u0bae\u0ba8\u0bbf\u0bb2\u0bc8 \u0b95\u0bbf\u0b9f\u0bcd: \u0b95\u0bca\u0ba3\u0bcd\u0b9f \u0bb5\u0bb4\u0b95\u0bcd\u0b95\u0bc1, \u0baa\u0bb2-\u0b9a\u0948\u0ba9\u0bb2\u0bcd \u0b9a\u0bae\u0bbf\u0b95\u0bcd\u0b9e\u0bc8 \u0ba8\u0bbf\u09ac\u0ba8\u0bcd\u0ba4\u0b95\u0bb0\u0bcd, \u0b95\u0bc8\u0baf\u0bc1\u0bae\u0bc8\u0baf\u0bbe\u0ba9 \u0baa\u0b95\u0bc1\u0baa\u0bcd\u0baa\u0bbe\u0baf\u0bcd\u0bb5\u0bbf, \u0b95\u0bbe\u0ba8\u0bcd\u0ba4 \u0b85\u0b9f\u0bbf\u0baa\u0bcd\u0baa\u0b9f\u0bc8, \u0b85\u0ba4\u0bbf\u0bb0\u0bcd\u0bb5\u0bc1 \u0b9a\u0bc6\u0ba9\u0bcd\u0b9a\u0bb0\u0bcd\u0b95\u0bb3\u0bcd, \u0bae\u0bb1\u0bcd\u0bb1\u0bc1\u0bae\u0bcd \u0b9a\u0bc1\u0bb0\u0bc1\u0bb3\u0bbe\u0b95 \u0b95\u0bc7\u0baa\u0bbf\u0bb3\u0bcd\u0b95\u0bb3\u0bcd.\" 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\/ta\/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\/ta\/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\">\u20ac<\/span>6,803.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?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=\"Add to cart\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Add to cart\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?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=\"Add to cart: \u201cBalanset-4\u201d\" rel=\"nofollow\" data-success_message=\"\u201cBalanset-4\u201d has been added to your cart\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Add to cart<\/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\/ta\/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\/ta\/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\/ta\/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\/ta\/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\">\u20ac<\/span>46.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?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=\"Add to cart\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Add to cart\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?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=\"Add to cart: \u201cMagnetic Stand Insize-60-kgf\u201d\" rel=\"nofollow\" data-success_message=\"\u201cMagnetic Stand Insize-60-kgf\u201d has been added to your cart\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Add to cart<\/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\/ta\/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\/ta\/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\/ta\/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\/ta\/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\">\u20ac<\/span>10.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?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=\"Add to cart\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Add to cart\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?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=\"Add to cart: \u201cReflective tape\u201d\" rel=\"nofollow\" data-success_message=\"\u201cReflective tape\u201d has been added to your cart\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Add to cart<\/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\/ta\/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\/ta\/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 \u0b95\u0bbf\u0b9f\u0bcd \u0b89\u0bb3\u0bcd\u0bb3\u0b9f\u0b95\u0bcd\u0b95\u0bae\u0bcd \u0b87\u0b9f\u0bc8\u0bae\u0bc1\u0b95 \u0b85\u0bb2\u0b95\u0bc1, \u0b9a\u0bc6\u0ba9\u0bcd\u0b9a\u0bb0\u0bcd\u0b95\u0bb3\u0bcd, tachometer \u0bae\u0bb1\u0bcd\u0bb1\u0bc1\u0bae\u0bcd \u0b85\u0ba3\u0bc1\u0b95\u0bc2\u0b9f\u0bc1\" 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\/ta\/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\/ta\/product\/dynamic-balancer-balanset-1a\/\" title=\"Dynamic balancer \u201cBalanset-1A\u201d OEM\">Dynamic balancer \u201cBalanset-1A\u201d OEM<\/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\">\u20ac<\/span>1,735.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?add-to-cart=4193\" data-quantity=\"1\" data-product_id=\"4193\" data-product_sku=\"BS-1OEM\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"Add to cart\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Add to cart\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/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=\"\/ta\/wp-json\/wp\/v2\/glossary\/259?add-to-cart=4193\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_4193\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"4193\" data-product_sku=\"BS-1OEM\" aria-label=\"Add to cart: \u201cDynamic balancer \u201cBalanset-1A\u201d OEM\u201d\" rel=\"nofollow\" data-success_message=\"\u201cDynamic balancer \u201cBalanset-1A\u201d OEM\u201d has been added to your cart\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Add to cart<\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_4193\" 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<p><strong>Sub-synchronous vibration<\/strong> is any vibration component whose frequency is <em>less than<\/em> the machine&#8217;s primary running speed (1&times;), and its appearance is one of the more serious signals a rotating machine can send. To understand why, it helps to set it against its opposite: <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/synchronous-vibration\/\">\u0b92\u0ba4\u0bcd\u0ba4\u0bbf\u0b9a\u0bc8\u0bb5\u0bbe\u0ba9 \u0b85\u0ba4\u0bbf\u0bb0\u0bcd\u0bb5\u0bc1<\/a>, which tracks the shaft at exact integer multiples of running speed. The distinction is not academic \u2014 it separates the everyday faults you can correct mechanically from the self-excited instabilities that demand a redesign or an immediate stop. This article defines both terms, lists the usual culprits, and shows how to tell them apart in an <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/fft\/\">FFT<\/a> spectrum.<\/p>\n<h2>1. What is Synchronous Vibration?<\/h2>\n<p>Synchronous vibration occurs at a frequency that is an integer multiple of the shaft&#8217;s rotational speed \u2014 it is &#8220;in sync&#8221; with the rotation. It is by far the most common category of machinery vibration.<\/p>\n<ul>\n<li>Vibration at exactly the <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/running-speed\/\">running speed<\/a> (1&times;) is synchronous.<\/li>\n<li>Vibration at twice running speed (2&times;), three times (3&times;), and so on are also synchronous, and are usually called <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/harmonics\/\">harmonics<\/a> \u0b87\u0baf\u0b95\u0bcd\u0b95 \u0bb5\u0bc7\u0b95.<\/li>\n<\/ul>\n<p>The vast majority of common faults manifest this way. <strong><a href=\"https:\/\/vibromera.eu\/ta\/glossary\/unbalance\/\">Unbalance<\/a><\/strong>, <strong><a href=\"https:\/\/vibromera.eu\/ta\/glossary\/misalignment\/\">misalignment<\/a><\/strong>, and <strong><a href=\"https:\/\/vibromera.eu\/ta\/glossary\/looseness\/\">\u0b87\u0baf\u0ba8\u0bcd\u0ba4\u0bbf\u0bb0 \u0ba4\u0bb3\u0bb0\u0bcd\u0baa\u0bcd\u0baa\u0bc1<\/a><\/strong> all produce synchronous vibration. Unbalance, for instance, always shows at 1&times; RPM and perfectly tracks any change in speed \u2014 double the RPM and the unbalance peak simply moves to the new 1&times; frequency. Because the forcing is locked to shaft angle, these are classic <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/forced-vibration\/\">\u0b95\u0b9f\u0bcd\u0b9f\u0bbe\u0baf \u0b85\u0ba4\u0bbf\u0bb0\u0bcd\u0bb5\u0bc1\u0b95\u0bb3\u0bcd<\/a>.<\/p>\n<h2>2. What is Sub-Synchronous Vibration?<\/h2>\n<p>Sub-synchronous vibration occurs at a frequency <em>below<\/em> 1&times; \u2014 the prefix &#8220;sub-&#8221; simply means &#8220;below.&#8221; Significant sub-synchronous content is often a serious warning sign, because it is typically produced by self-excited, unstable rotor-dynamic phenomena rather than by a simple mechanical defect. The crucial difference is the source of the energy: in synchronous faults an external geometric error drives the rotor once per turn, whereas in sub-synchronous instability the forcing function is generated by the <em>motion of the rotor itself<\/em> interacting with its bearings or seals. That feedback loop is what makes these conditions a hallmark of <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/rotor-instability\/\">\u0b9a\u0bc1\u0bb4\u0bb2\u0bbf \u0985\u09b8\u09cd\u0ba4\u0bbf\u0bb0\u0ba4\u0bcd\u0ba4\u0ba9\u0bcd\u0bae\u0bc8<\/a>.<\/p>\n<h2>3. Common Causes of Sub-Synchronous Vibration<\/h2>\n<p>Sub-synchronous vibration is a major concern in high-speed turbomachinery running in fluid-film <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/journal-bearing\/\">\u0baa\u0ba4\u0bcd\u0ba4\u0bbf\u0bb0\u0bbf\u0b95\u0bcd\u0b95\u0bc8 \u0ba4\u0bbe\u0b99\u0bcd\u0b95\u0bbf\u0baf\u0bbf\u0bb2\u0bcd<\/a>.<\/p>\n<h3>3.1 Oil Whirl<\/h3>\n<p>This is the most common form of sub-synchronous instability. In a fluid-film bearing the hydrodynamic oil film that supports the shaft can begin to circulate and push the shaft ahead of it, a phenomenon known as <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/oil-whirl\/\">oil whirl<\/a>. Because the average velocity of the oil film is a little under half the shaft surface speed, the resulting <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/whirl\/\">whirl<\/a> appears at roughly <strong>0.42 to 0.48 times running speed (0.42&times;&ndash;0.48&times;)<\/strong>. Oil whirl is often load- and temperature-dependent, and may appear or disappear as bearing load, oil temperature, or speed change.<\/p>\n<h3>3.2 Oil Whip<\/h3>\n<p>Oil whip is a more severe and dangerous evolution of oil whirl. It occurs when the whirl frequency rises to meet \u2014 and then &#8220;locks onto&#8221; \u2014 the rotor&#8217;s first natural frequency, or <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/critical-speed\/\">critical speed<\/a>. Once locked, the sub-synchronous amplitude can grow very large and will not disappear as speed increases; instead the vibration stays pinned at the critical-speed frequency even as the machine accelerates further. This locked, escalating condition \u2014 closely related to <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/shaft-whip\/\">shaft whip<\/a> \u2014 is highly destructive and generally requires an immediate <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/shutdown\/\">shutdown<\/a>.<\/p>\n<h3>3.3 Rotor-to-Stator Rub<\/h3>\n<p>Contact between the rotor and a stationary part \u2014 a <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/rotor-rub\/\">rotor rub<\/a> \u2014 can also induce sub-synchronous vibration, often at integer fractions of running speed such as <strong>0.5&times;<\/strong>. A clean 0.5&times; component is a classic sign of a rub that bounces the rotor once every two revolutions. Other sources of <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/subharmonic\/\">sub-harmonic<\/a> response include severe looseness and certain rub-driven nonlinearities.<\/p>\n<h2>4. Telling Them Apart in an FFT Spectrum<\/h2>\n<p>Separating the two families on a <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/spectrum\/\">spectrum<\/a> is largely a matter of where the peaks fall relative to 1&times;:<\/p>\n<ul>\n<li><strong>Synchronous peaks:<\/strong> locate the 1&times; RPM peak (running speed) and look for peaks on exact integer multiples \u2014 2&times;, 3&times;, and so on.<\/li>\n<li><strong>Sub-synchronous peaks:<\/strong> look for any significant peak that appears <em>before<\/em> the 1&times; peak on the frequency axis. A peak near 45% of running speed is a textbook indicator of oil whirl.<\/li>\n<\/ul>\n<p>Because the diagnosis hinges on the exact ratio of the peak to running speed, a precise speed reference is essential \u2014 small errors in assumed RPM can blur a 0.48&times; whirl into something ambiguous. <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/order-analysis\/\">Order analysis<\/a> referenced to a once-per-revolution tachometer pulse removes that ambiguity by expressing the spectrum directly in orders of running speed.<\/p>\n<h2>5. Why the Distinction is Critical<\/h2>\n<p>Knowing which family you are looking at determines the entire response:<\/p>\n<ul>\n<li><strong>Synchronous issues<\/strong> (such as unbalance) are forced vibrations and can usually be corrected mechanically \u2014 by <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/balancing\/\">\u0b9a\u0bae\u0ba8\u0bbf\u0bb2\u0bc8\u0baa\u0bcd\u0baa\u0b9f\u0bc1\u0ba4\u0bcd\u0ba4\u0bc1\u0ba4\u0bb2\u0bcd<\/a>, alignment, or tightening fasteners.<\/li>\n<li><strong>Sub-synchronous issues<\/strong> (such as oil whip) are <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/self-excited-vibration\/\">self-excited vibrations<\/a> or instabilities. They point to a fundamental problem in the <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/rotor-bearing-system\/\">\u0bb0\u0bcb\u0b9f\u0bcd\u0b9f\u0bb0\u0bcd-\u0b86\u0ba4\u0bb0\u0ba3\u0bae\u0bcd \u0bae\u0bc1\u0bb1\u0bc8<\/a> and cannot be cured by balancing. Fixes typically involve changing the bearing design (for example to tilting-pad bearings), adjusting oil temperature or pressure, increasing bearing load, or modifying the rotor.<\/li>\n<\/ul>\n<p>For this reason a high-amplitude sub-synchronous peak is generally treated as a more serious alarm than an equally large synchronous peak. In practice an engineer first confirms the machine is well balanced and aligned \u2014 a portable analyser such as the <a href=\"https:\/\/vibromera.eu\/ta\/product\/balanset-1\/\">Balanset-1A<\/a> measures the 1&times; amplitude and <a href=\"https:\/\/vibromera.eu\/ta\/glossary\/phase\/\">phase<\/a> needed to rule out, or correct, the synchronous causes \u2014 so that any sub-synchronous component remaining on the spectrum can be confidently attributed to an instability rather than to a curable mechanical fault.<\/p>\n<hr>\n<p><a href=\"https:\/\/vibromera.eu\/ta\/glossary\/\">\u2190 \u0bae\u0bc1\u0ba4\u0ba9\u0bcd\u0bae\u0bc8 \u0b85\u0b9f\u0bcd\u0b9f\u0bb5\u0ba3\u0bc8\u0b95\u0bcd\u0b95\u0bc1 \u0ba4\u0bbf\u0bb0\u0bc1\u0bae\u0bcd\u0baa\u0bb5\u0bc1\u0bae\u0bcd<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>Learn the critical difference between sub-synchronous and synchronous vibration. Understand how synchronous vibration relates to unbalance and how sub-synchronous vibration indicates serious rotor instabilities like oil whirl.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"ai_generated_summary":"","footnotes":""},"categories":[109,110],"tags":[],"class_list":["post-259","glossary","type-glossary","status-publish","hentry","category-glossary","category-vibration-diagnostics"],"_links":{"self":[{"href":"https:\/\/vibromera.eu\/ta\/wp-json\/wp\/v2\/glossary\/259","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vibromera.eu\/ta\/wp-json\/wp\/v2\/glossary"}],"about":[{"href":"https:\/\/vibromera.eu\/ta\/wp-json\/wp\/v2\/types\/glossary"}],"version-history":[{"count":1,"href":"https:\/\/vibromera.eu\/ta\/wp-json\/wp\/v2\/glossary\/259\/revisions"}],"predecessor-version":[{"id":101314,"href":"https:\/\/vibromera.eu\/ta\/wp-json\/wp\/v2\/glossary\/259\/revisions\/101314"}],"wp:attachment":[{"href":"https:\/\/vibromera.eu\/ta\/wp-json\/wp\/v2\/media?parent=259"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vibromera.eu\/ta\/wp-json\/wp\/v2\/categories?post=259"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vibromera.eu\/ta\/wp-json\/wp\/v2\/tags?post=259"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}