{"id":100302,"date":"2026-02-15T20:44:57","date_gmt":"2026-02-15T20:44:57","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100302"},"modified":"2026-05-25T16:30:23","modified_gmt":"2026-05-25T16:30:23","slug":"vibration-velocity","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/nb\/calculators\/vibration-velocity\/","title":{"rendered":"ISO 10816 Vibrasjonshastighetsgrenser \u2014 Sonekalkulator"},"content":{"rendered":"\n<script type=\"application\/ld+json\">\n{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Vibration Velocity Limits Calculator (ISO 10816)\",\"alternateName\":[\"ISO 10816 Zone Calculator\",\"Vibration Severity Calculator\"],\"description\":\"Check permissible vibration velocity per ISO 10816 \/ ISO 20816. Select machine class, enter measured velocity to get zone evaluation A\/B\/C\/D with color-coded results.\",\"url\":\"https:\/\/vibromera.eu\/calculators\/vibration-velocity\/\",\"applicationCategory\":\"Engineering Calculator\",\"operatingSystem\":\"Any (Web Browser)\",\"offers\":{\"@type\":\"Offer\",\"price\":\"0\",\"priceCurrency\":\"EUR\"},\"creator\":{\"@type\":\"Organization\",\"name\":\"Vibromera\",\"url\":\"https:\/\/vibromera.eu\/\"},\"datePublished\":\"2024-01-01\",\"dateModified\":\"2025-02-14\",\"inLanguage\":\"en\",\"isAccessibleForFree\":true,\"featureList\":[\"ISO 10816 zone evaluation\",\"Machine classes I-IV\",\"Color-coded zone bar\",\"Metric and Imperial units\",\"Auto-calculation on input change\",\"URL parameter sharing\",\"Calculation history\"],\"keywords\":\"vibration velocity, ISO 10816, ISO 20816, zone evaluation, machine vibration\"}\n<\/script>\n\n<script type=\"application\/ld+json\">\n{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[\n{\"@type\":\"Question\",\"name\":\"What is vibration velocity?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Vibration velocity is the speed at which a vibrating surface moves back and forth, measured in mm\/s RMS. It is the most widely used parameter for evaluating machine condition because it correlates well with vibration energy and bearing\/structural damage. ISO 10816 and ISO 20816 define permissible limits based on machine class.\"}},\n{\"@type\":\"Question\",\"name\":\"What is the difference between ISO 10816 and ISO 20816?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"ISO 20816 is the modern replacement for ISO 10816. The zone boundaries and machine classes are essentially the same for most non-rotating parts (housing) vibration evaluation. ISO 20816 adds shaft vibration requirements and updated measurement practices. For broadband velocity RMS evaluation on machine housings, the classic ISO 10816 limits still apply.\"}},\n{\"@type\":\"Question\",\"name\":\"How do I measure vibration velocity?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Vibration velocity is measured with an accelerometer or velocity sensor mounted on the machine bearing housing. The sensor signal is processed by a vibration analyzer or portable instrument to produce a broadband RMS velocity value in mm\/s. Measurements should be taken in three directions: horizontal, vertical, and axial.\"}},\n{\"@type\":\"Question\",\"name\":\"What should I do if the machine is in Zone C or D?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Zone C means the vibration level is tolerable only for limited periods \u2014 plan corrective action. Zone D means the vibration is severe enough to cause damage \u2014 stop the machine immediately if possible and investigate root cause. Common corrective actions include re-balancing, alignment correction, bearing replacement, or addressing structural resonance.\"}},\n{\"@type\":\"Question\",\"name\":\"Which sensor is best for vibration velocity measurement?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"For most industrial machines, a piezoelectric accelerometer with integrated electronics (IEPE\/ICP type) is the standard choice. The acceleration signal is electronically integrated to velocity. For low-frequency applications below 10 Hz, electrodynamic velocity sensors may be preferred. Ensure the sensor frequency range covers 10-1000 Hz per ISO 10816.\"}}\n]}\n<\/script>\n\n<script type=\"application\/ld+json\">\n{\"@context\":\"https:\/\/schema.org\",\"@type\":\"BreadcrumbList\",\"itemListElement\":[\n{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/vibromera.eu\/\"},\n{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Calculators\",\"item\":\"https:\/\/vibromera.eu\/calculators\/\"},\n{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Vibration Velocity ISO 10816\",\"item\":\"https:\/\/vibromera.eu\/calculators\/vibration-velocity\/\"}\n]}\n<\/script>\n\n<link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n\n<link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin>\n\n<link href=\"https:\/\/fonts.googleapis.com\/css2?family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&#038;family=JetBrains+Mono:wght@400;500;600&#038;family=Fraunces:opsz,wght@9..144,700;9..144,800&#038;display=swap\" rel=\"stylesheet\">\n\n<link rel=\"stylesheet\" href=\"https:\/\/cdn.jsdelivr.net\/npm\/katex@0.16.11\/dist\/katex.min.css\">\n\n<style>\n:root {\n    --vc-bg: #f4f1ec;\n    --vc-surface: #ffffff;\n    --vc-surface-alt: #f8f6f2;\n    --vc-ink: #1a1a1a;\n    --vc-ink-secondary: #5a5650;\n    --vc-ink-muted: #8a857e;\n    --vc-accent: #c85a2a;\n    --vc-accent-hover: #b04d22;\n    --vc-accent-light: #fdf0ea;\n    --vc-blue: #2a5c8c;\n    --vc-blue-light: #eaf1f8;\n    --vc-green: #2a7a4b;\n    --vc-green-light: #eaf8ef;\n    --vc-yellow: #a67c00;\n    --vc-yellow-light: #fef9e8;\n    --vc-red: #b91c1c;\n    --vc-red-light: #fef2f2;\n    --vc-border: #d9d4cc;\n    --vc-border-light: #e8e4dd;\n    --vc-shadow: 0 1px 3px rgba(26,26,26,0.06), 0 4px 12px rgba(26,26,26,0.04);\n    --vc-shadow-lg: 0 4px 12px rgba(26,26,26,0.08), 0 16px 40px rgba(26,26,26,0.06);\n    --vc-radius: 8px;\n    --vc-radius-lg: 12px;\n    --vc-font: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;\n    --vc-mono: 'JetBrains Mono', 'Consolas', 'Monaco', monospace;\n    --vc-display: 'Fraunces', Georgia, serif;\n}\n\n.vc-calculator {\n    font-family: var(--vc-font);\n    font-size: 15px;\n    line-height: 1.65;\n    color: var(--vc-ink);\n    max-width: 960px;\n    margin: 0 auto;\n    padding: 20px 16px 40px;\n    -webkit-font-smoothing: antialiased;\n}\n.vc-calculator *, .vc-calculator *::before, .vc-calculator *::after { box-sizing: border-box; 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}\n.vc-faq-a-inner p { margin:0 0 8px; }\n.vc-faq-a-inner p:last-child { margin-bottom:0; }\n.vc-faq-a-inner ul { margin:4px 0 8px 16px; padding:0; }\n.vc-faq-a-inner li { margin-bottom:3px; }\n\n.vc-related { display:flex; flex-wrap:wrap; gap:10px; margin-top:16px; }\n.vc-related-link { display:inline-block; padding:8px 16px; font-family:var(--vc-font); font-size:13px; font-weight:600; background:var(--vc-surface-alt); color:var(--vc-ink-secondary); border:1px solid var(--vc-border); border-radius:var(--vc-radius); text-decoration:none; transition:all 0.15s; }\n.vc-related-link:hover { border-color:var(--vc-accent); color:var(--vc-accent); background:var(--vc-accent-light); }\n\n.vc-promo { margin-top:24px; padding:20px; background:linear-gradient(135deg, var(--vc-accent-light), var(--vc-surface)); border:1px solid var(--vc-border); border-radius:var(--vc-radius-lg); display:flex; align-items:center; gap:16px; }\n.vc-promo-text { flex:1; font-size:14px; color:var(--vc-ink-secondary); }\n.vc-promo-text strong { color:var(--vc-ink); }\n.vc-promo-link { padding:8px 20px; font-size:13px; font-weight:700; color:#fff; background:var(--vc-accent); border-radius:var(--vc-radius); text-decoration:none; white-space:nowrap; transition:background 0.15s; }\n.vc-promo-link:hover { background:var(--vc-accent-hover); }\n\n.vc-footer { text-align:center; padding:32px 16px; font-size:13px; color:var(--vc-ink-muted); }\n.vc-footer a { color:var(--vc-accent); text-decoration:none; }\n.vc-footer a:hover { text-decoration:underline; }\n.vc-footer-links { margin-top:8px; font-size:12px; }\n.vc-footer-links a { margin:0 8px; }\n\n@media print {\n    .vc-section-body { max-height:none!important; }\n    .vc-faq-a { max-height:none!important; }\n    .vc-results { max-height:none!important; padding:24px!important; }\n    .vc-copy-btn, .vc-section-chevron, .vc-faq-chevron, .vc-presets, .vc-promo { display:none!important; }\n}\n<\/style>\n\n<div class=\"vc-calculator\" id=\"vc-vibration-velocity\">\n\n<header class=\"vc-header\">\n    <p class=\"vc-header-eyebrow\">Free Engineering Tool<\/p>\n    <h1 class=\"vc-header-title\">Permissible Vibration Velocity (ISO 10816)<\/h1>\n    <p class=\"vc-header-subtitle\">Look up permissible vibration velocity limits per ISO 10816 \/ ISO 20816. Select machine class, enter measured velocity to get zone evaluation A\/B\/C\/D.<\/p>\n    <div class=\"vc-badges\">\n        <span class=\"vc-badge\">ISO 10816<\/span>\n        <span class=\"vc-badge\">ISO 20816<\/span>\n        <span class=\"vc-badge\">Zones A \/ B \/ C \/ D<\/span>\n    <\/div>\n<\/header>\n\n<div class=\"vc-card\">\n    <div class=\"vc-unit-bar\">\n        <button type=\"button\" class=\"vc-unit-btn vc-active\" data-system=\"metric\">Metric (mm\/s)<\/button>\n        <button type=\"button\" class=\"vc-unit-btn\" data-system=\"imperial\">Imperial (in\/s)<\/button>\n    <\/div>\n\n    <form class=\"vc-form\" id=\"vc-form\" autocomplete=\"off\">\n        <div class=\"vc-form-grid\">\n            <div class=\"vc-field\">\n                <label class=\"vc-label\" for=\"vc-class\">Machine Class (ISO 10816)<\/label>\n                <select class=\"vc-select\" id=\"vc-class\">\n                    <option value=\"I\">Class I \u2014 Small machines up to 15 kW<\/option>\n                    <option value=\"II\" selected>Class II \u2014 Medium machines 15\u201375 kW<\/option>\n                    <option value=\"III\">Class III \u2014 Large machines on rigid foundations (&gt;75 kW)<\/option>\n                    <option value=\"IV\">Class IV \u2014 Large machines on flexible foundations, turbo<\/option>\n                <\/select>\n            <\/div>\n            <div class=\"vc-field\">\n                <label class=\"vc-label\" for=\"vc-velocity\">Measured Vibration Velocity <span class=\"vc-label-hint\" id=\"vc-vel-unit-hint\">(mm\/s RMS)<\/span><\/label>\n                <input class=\"vc-input\" type=\"number\" id=\"vc-velocity\" inputmode=\"decimal\" step=\"any\" min=\"0\" placeholder=\"e.g. 3.2\" value=\"3.2\">\n            <\/div>\n        <\/div>\n\n        <div class=\"vc-presets\">\n            <div class=\"vc-presets-label\">Quick presets<\/div>\n            <button type=\"button\" class=\"vc-preset-btn\" data-cls=\"II\" data-vel=\"2.1\">Small motor 2.1 mm\/s<\/button>\n            <button type=\"button\" class=\"vc-preset-btn\" data-cls=\"III\" data-vel=\"4.5\">Pump 4.5 mm\/s<\/button>\n            <button type=\"button\" class=\"vc-preset-btn\" data-cls=\"IV\" data-vel=\"7.2\">Turbine 7.2 mm\/s<\/button>\n        <\/div>\n    <\/form>\n\n    <!-- Results -->\n    <div class=\"vc-results\" id=\"vc-results\">\n        <div class=\"vc-results-head\">\n            <h2 class=\"vc-results-title\">Results<\/h2>\n            <button type=\"button\" class=\"vc-copy-btn\" id=\"vc-copy-btn\">\n                <svg width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><rect x=\"9\" y=\"9\" width=\"13\" height=\"13\" rx=\"2\"\/><path d=\"M5 15H4a2 2 0 01-2-2V4a2 2 0 012-2h9a2 2 0 012 2v1\"\/><\/svg>\n                Copy\n            <\/button>\n        <\/div>\n        <div class=\"vc-result-grid\">\n            <div class=\"vc-rcard vc-rcard-primary\" id=\"vc-zone-card\">\n                <div class=\"vc-rcard-label\">Zone Evaluation<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-zone\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Machine Class<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-class\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Measured Velocity<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-vel\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Equivalent (in\/s)<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-vel-ins\">\u2014<\/div>\n            <\/div>\n        <\/div>\n\n        <!-- Zone Bar -->\n        <div class=\"vc-zone-bar-wrap\">\n            <div class=\"vc-zone-bar\" id=\"vc-zone-bar\"><\/div>\n        <\/div>\n\n        <!-- Zone Table -->\n        <table class=\"vc-zone-table\" id=\"vc-zone-table\">\n            <thead><tr><th>Zone<\/th><th>Velocity Range<\/th><th>Meaning<\/th><\/tr><\/thead>\n            <tbody id=\"vc-zone-tbody\"><\/tbody>\n        <\/table>\n    <\/div>\n<\/div>\n\n<!-- Theory -->\n<div class=\"vc-section vc-open\" id=\"vc-sec-theory\">\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"true\">\n        <span class=\"vc-section-toggle-text\">\n            <span class=\"vc-section-icon\">\ud83d\udcd8<\/span>\n            <span class=\"vc-section-title\">Theory &amp; Reference<\/span>\n        <\/span>\n        <svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg>\n    <\/button>\n    <div class=\"vc-section-body\">\n        <div class=\"vc-section-inner vc-theory\">\n            <h3>Vibration Velocity RMS<\/h3>\n            <p>The vibration velocity RMS value is related to peak velocity by:<\/p>\n            <div class=\"vc-formula-box\" id=\"vc-katex-1\"><\/div>\n            <ul>\n                <li><strong>v<sub>RMS<\/sub><\/strong> \u2014 root mean square vibration velocity (mm\/s)<\/li>\n                <li><strong>v<sub>peak<\/sub><\/strong> \u2014 peak vibration velocity (mm\/s)<\/li>\n            <\/ul>\n            <p>ISO 10816 evaluates machine vibration severity based on broadband v<sub>RMS<\/sub> (typically 10\u20131000 Hz). Machines are classified into four groups, and each group has four evaluation zones (A, B, C, D).<\/p>\n\n            <h3>ISO 10816 Zone Boundaries \u2014 All Classes<\/h3>\n            <table class=\"vc-table\">\n                <thead><tr><th>Zone<\/th><th>Class I<br>(\u226415 kW)<\/th><th>Class II<br>(15\u201375 kW)<\/th><th>Class III<br>(rigid, &gt;75 kW)<\/th><th>Class IV<br>(flexible, turbo)<\/th><\/tr><\/thead>\n                <tbody>\n                    <tr><td><strong>A<\/strong> (New)<\/td><td>\u2264 0.71<\/td><td>\u2264 1.12<\/td><td>\u2264 1.8<\/td><td>\u2264 2.8<\/td><\/tr>\n                    <tr><td><strong>B<\/strong> (Acceptable)<\/td><td>0.71 \u2013 1.8<\/td><td>1.12 \u2013 2.8<\/td><td>1.8 \u2013 4.5<\/td><td>2.8 \u2013 7.1<\/td><\/tr>\n                    <tr><td><strong>C<\/strong> (Tolerable)<\/td><td>1.8 \u2013 4.5<\/td><td>2.8 \u2013 7.1<\/td><td>4.5 \u2013 11.2<\/td><td>7.1 \u2013 18<\/td><\/tr>\n                    <tr><td><strong>D<\/strong> (Damaging)<\/td><td>&gt; 4.5<\/td><td>&gt; 7.1<\/td><td>&gt; 11.2<\/td><td>&gt; 18<\/td><\/tr>\n                <\/tbody>\n            <\/table>\n            <p>All values in mm\/s RMS.<\/p>\n\n            <h3>Practical Example<\/h3>\n            <div class=\"vc-example-box\">\n                <div class=\"vc-example-title\">Example \u2014 45 kW Motor (Class II)<\/div>\n                <p><strong>Given:<\/strong> Measured vibration velocity = 3.2 mm\/s RMS<\/p>\n                <p>Class II boundaries: A \u2264 1.12, B \u2264 2.8, C \u2264 7.1, D &gt; 7.1<\/p>\n                <p>3.2 mm\/s exceeds B boundary (2.8) but is below C boundary (7.1)<\/p>\n                <p>Result: <strong>Zone C<\/strong> \u2014 Tolerable for limited periods only. Plan corrective action.<\/p>\n            <\/div>\n        <\/div>\n    <\/div>\n<\/div>\n\n<!-- Related -->\n<div class=\"vc-section\" id=\"vc-sec-related\">\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\">\n        <span class=\"vc-section-toggle-text\">\n            <span class=\"vc-section-icon\">\ud83d\udd17<\/span>\n            <span class=\"vc-section-title\">Related Calculators<\/span>\n        <\/span>\n        <svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg>\n    <\/button>\n    <div class=\"vc-section-body\">\n        <div class=\"vc-section-inner\">\n            <div class=\"vc-related\">\n                <a class=\"vc-related-link\" href=\"\/calculators\/residual-unbalance-iso1940\/\">Residual Unbalance (ISO 21940)<\/a>\n                <a class=\"vc-related-link\" href=\"\/calculators\/trial-weight-calculator\/\">Trial Weight Calculator<\/a>\n                <a class=\"vc-related-link\" href=\"\/calculators\/vibration-displacement\/\">Vibration Displacement<\/a>\n                <a class=\"vc-related-link\" href=\"\/calculators\/vibration-acceleration\/\">Vibration Acceleration<\/a>\n            <\/div>\n        <\/div>\n    <\/div>\n<\/div>\n\n<!-- FAQ -->\n<div class=\"vc-section\" id=\"vc-sec-faq\">\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\">\n        <span class=\"vc-section-toggle-text\">\n            <span class=\"vc-section-icon\">\u2753<\/span>\n            <span class=\"vc-section-title\">Frequently Asked Questions<\/span>\n        <\/span>\n        <svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg>\n    <\/button>\n    <div class=\"vc-section-body\">\n        <div class=\"vc-section-inner\">\n            <div class=\"vc-faq-list\" id=\"vc-faq-list\"><\/div>\n        <\/div>\n    <\/div>\n<\/div>\n\n<!-- Promo -->\n<div class=\"vc-promo\">\n    <div class=\"vc-promo-text\">\n        <strong>Vibromera \u2014 Portable Balancing &amp; Vibration Analysis<\/strong><br>\n        Professional field balancing instruments with built-in ISO 10816 zone evaluation. Measure, analyze, and balance on-site. Used in 50+ countries.\n    <\/div>\n    <a class=\"vc-promo-link\" href=\"https:\/\/vibromera.eu\/\" target=\"_blank\" rel=\"noopener\">Learn More<\/a>\n<\/div>\n\n<footer class=\"vc-footer\">\n    <p>\u00a9 2024\u20132025 <a href=\"https:\/\/vibromera.eu\/\">Vibromera<\/a> \u2014 Engineering Calculators<\/p>\n    <p style=\"font-size:12px;margin-top:4px;\">Based on ISO 10816 \/ ISO 20816. Last updated: February 2025<\/p>\n    <div class=\"vc-footer-links\">\n        <a href=\"\/calculators\/engineering-calculators\/\">All Calculators<\/a>\n        <a href=\"https:\/\/vibromera.eu\/contacts\/\">Contact<\/a>\n    <\/div>\n<\/footer>\n\n<\/div>\n\n<script src=\"https:\/\/cdn.jsdelivr.net\/npm\/katex@0.16.11\/dist\/katex.min.js\"><\/script>\n<script>\n(function() {\n    'use strict';\n\n    var SLUG = 'vibration-velocity';\n    var unitSystem = 'metric';\n    var MMS_TO_INS = 1\/25.4;\n\n    var ZONES = { 'I':[0.71,1.8,4.5], 'II':[1.12,2.8,7.1], 'III':[1.8,4.5,11.2], 'IV':[2.8,7.1,18] };\n    var CLASS_DESC = { 'I':'Small machines up to 15 kW', 'II':'Medium machines 15\u201375 kW', 'III':'Large machines on rigid foundations (>75 kW)', 'IV':'Large machines on flexible foundations, turbo' };\n    var ZONE_MEANINGS = { 'A':'New or repaired \u2014 excellent condition', 'B':'Acceptable for long-term operation', 'C':'Tolerable for limited periods only', 'D':'Damaging \u2014 immediate action required' };\n    var ZONE_BG = { 'A':'#e8f5e9', 'B':'#fffde7', 'C':'#fff3e0', 'D':'#ffebee' };\n    var ZONE_TEXT = { 'A':'#2e7d32', 'B':'#f57f17', 'C':'#e65100', 'D':'#c62828' };\n    var ZONE_DOT = { 'A':'#4caf50', 'B':'#fbc02d', 'C':'#ff9800', 'D':'#e53935' };\n\n    function $(id) { return document.getElementById(id); }\n\n    function getZone(cls, v) {\n        var b = ZONES[cls];\n        if (v <= b[0]) return 'A';\n        if (v <= b[1]) return 'B';\n        if (v <= b[2]) return 'C';\n        return 'D';\n    }\n\n    function buildZoneBar(cls, velMms) {\n        var b = ZONES[cls];\n        var maxVal = b[2] * 1.5;\n        var barEl = $('vc-zone-bar');\n        if (!barEl) return;\n\n        var segA = b[0]\/maxVal*100;\n        var segB = (b[1]-b[0])\/maxVal*100;\n        var segC = (b[2]-b[1])\/maxVal*100;\n        var segD = 100 - segA - segB - segC;\n        if (segD < 5) segD = 5;\n        var total = segA + segB + segC + segD;\n        segA = segA\/total*100; segB = segB\/total*100; segC = segC\/total*100; segD = segD\/total*100;\n\n        var html = '';\n        html += '<div class=\"vc-zone-seg vc-zone-seg-a\" style=\"width:'+segA+'%\">A<\/div>';\n        html += '<div class=\"vc-zone-seg vc-zone-seg-b\" style=\"width:'+segB+'%\">B<\/div>';\n        html += '<div class=\"vc-zone-seg vc-zone-seg-c\" style=\"width:'+segC+'%\">C<\/div>';\n        html += '<div class=\"vc-zone-seg vc-zone-seg-d\" style=\"width:'+segD+'%\">D<\/div>';\n\n        if (velMms !== null && velMms >= 0) {\n            var pos;\n            if (velMms <= 0) pos = 0;\n            else if (velMms >= maxVal) pos = segA + segB + segC + segD * 0.9;\n            else {\n                if (velMms <= b[0]) pos = (velMms\/b[0]) * segA;\n                else if (velMms <= b[1]) pos = segA + ((velMms-b[0])\/(b[1]-b[0])) * segB;\n                else if (velMms <= b[2]) pos = segA + segB + ((velMms-b[1])\/(b[2]-b[1])) * segC;\n                else pos = segA + segB + segC + Math.min(((velMms-b[2])\/(maxVal-b[2])) * segD, segD * 0.95);\n            }\n            html += '<div class=\"vc-zone-marker\" style=\"left:'+pos+'%\"><\/div>';\n        }\n        barEl.innerHTML = html;\n    }\n\n    function buildZoneTable(cls, velMms) {\n        var b = ZONES[cls];\n        var zone = (velMms !== null) ? getZone(cls, velMms) : null;\n        var tbody = $('vc-zone-tbody');\n        if (!tbody) return;\n        var rows = [\n            { z:'A', range:'\u2264 '+b[0]+' mm\/s', meaning:ZONE_MEANINGS['A'] },\n            { z:'B', range:b[0]+' \u2013 '+b[1]+' mm\/s', meaning:ZONE_MEANINGS['B'] },\n            { z:'C', range:b[1]+' \u2013 '+b[2]+' mm\/s', meaning:ZONE_MEANINGS['C'] },\n            { z:'D', range:'> '+b[2]+' mm\/s', meaning:ZONE_MEANINGS['D'] }\n        ];\n        var html = '';\n        rows.forEach(function(r) {\n            var active = (zone === r.z) ? ' vc-zt-active' : '';\n            var bgStyle = (zone === r.z) ? 'background:'+ZONE_BG[r.z] : '';\n            var fontStyle = (zone === r.z) ? 'font-weight:700;color:'+ZONE_TEXT[r.z] : '';\n            html += '<tr><td class=\"'+active+'\" style=\"'+bgStyle+';'+fontStyle+'\">Zone '+r.z+'<\/td><td class=\"'+active+'\" style=\"'+bgStyle+'\">'+r.range+'<\/td><td class=\"'+active+'\" style=\"'+bgStyle+'\">'+r.meaning+'<\/td><\/tr>';\n        });\n        tbody.innerHTML = html;\n    }\n\n    function calculate() {\n        var cls = $('vc-class').value;\n        var velRaw = $('vc-velocity').value;\n        var velVal = parseFloat(velRaw);\n        var hasVel = velRaw !== '' && !isNaN(velVal) && velVal >= 0;\n\n        var velMms = null;\n        if (hasVel) {\n            velMms = unitSystem === 'imperial' ? velVal \/ MMS_TO_INS : velVal;\n        }\n\n        $('vc-r-class').innerHTML = 'Class ' + cls + ' <span class=\"vc-rcard-unit\">' + CLASS_DESC[cls] + '<\/span>';\n\n        if (hasVel && velMms !== null) {\n            var zone = getZone(cls, velMms);\n            $('vc-r-zone').innerHTML = '<span style=\"color:'+ZONE_TEXT[zone]+'\">Zone ' + zone + '<\/span> <span class=\"vc-rcard-unit\" style=\"color:'+ZONE_TEXT[zone]+'\">' + ZONE_MEANINGS[zone] + '<\/span>';\n            var card = $('vc-zone-card');\n            card.style.background = 'linear-gradient(135deg, '+ZONE_BG[zone]+' 0%, var(--vc-surface) 100%)';\n            card.style.borderColor = ZONE_DOT[zone];\n\n            $('vc-r-vel').innerHTML = velMms.toFixed(2) + ' <span class=\"vc-rcard-unit\">mm\/s RMS<\/span>';\n            $('vc-r-vel-ins').innerHTML = (velMms * MMS_TO_INS).toFixed(4) + ' <span class=\"vc-rcard-unit\">in\/s RMS<\/span>';\n        } else {\n            $('vc-r-zone').innerHTML = '<span class=\"vc-rcard-unit\">Enter velocity to evaluate<\/span>';\n            var card = $('vc-zone-card');\n            card.style.background = '';\n            card.style.borderColor = '';\n            $('vc-r-vel').innerHTML = '\u2014';\n            $('vc-r-vel-ins').innerHTML = '\u2014';\n        }\n\n        buildZoneBar(cls, velMms);\n        buildZoneTable(cls, velMms);\n        $('vc-results').classList.add('vc-visible');\n\n        \/* URL params *\/\n        var u = new URL(window.location);\n        u.searchParams.set('machineClass', cls);\n        if (hasVel) u.searchParams.set('velocity', velRaw);\n        history.replaceState(null, '', u.toString());\n\n        \/* History *\/\n        if (hasVel && velMms !== null) {\n            var z = getZone(cls, velMms);\n            saveHistory({ machineClass:cls, velocity:velRaw, _summary:'Class '+cls+', v='+velMms.toFixed(2)+' mm\/s \u2192 Zone '+z });\n        }\n    }\n\n    \/* \u2500\u2500 UNIT TOGGLE \u2500\u2500 *\/\n    var unitBtns = document.querySelectorAll('.vc-unit-btn');\n    unitBtns.forEach(function(btn) {\n        btn.addEventListener('click', function() {\n            unitBtns.forEach(function(b) { b.classList.remove('vc-active'); });\n            this.classList.add('vc-active');\n            unitSystem = this.getAttribute('data-system');\n            $('vc-vel-unit-hint').textContent = unitSystem === 'imperial' ? '(in\/s RMS)' : '(mm\/s RMS)';\n            try { localStorage.setItem('vc_units', unitSystem); } catch(e) {}\n            calculate();\n        });\n    });\n\n    \/* \u2500\u2500 PRESETS \u2500\u2500 *\/\n    document.querySelectorAll('.vc-preset-btn').forEach(function(btn) {\n        btn.addEventListener('click', function(e) {\n            e.preventDefault();\n            var vel = parseFloat(this.getAttribute('data-vel'));\n            $('vc-class').value = this.getAttribute('data-cls');\n            $('vc-velocity').value = unitSystem === 'imperial' ? (vel * MMS_TO_INS).toFixed(4) : vel;\n            calculate();\n        });\n    });\n\n    \/* \u2500\u2500 AUTO-CALCULATE \u2500\u2500 *\/\n    $('vc-form').addEventListener('input', calculate);\n    $('vc-form').addEventListener('change', calculate);\n\n    \/* \u2500\u2500 COPY \u2500\u2500 *\/\n    $('vc-copy-btn').addEventListener('click', function() {\n        var text = 'Vibration Velocity Evaluation (ISO 10816)\\n' +\n            '\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\\n' +\n            'Machine Class: ' + $('vc-class').value + '\\n' +\n            'Velocity: ' + $('vc-r-vel').textContent + '\\n' +\n            'Zone: ' + $('vc-r-zone').textContent + '\\n' +\n            '\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\\n' +\n            'vibromera.eu\/calculators\/vibration-velocity\/';\n\n        if (navigator.clipboard) {\n            navigator.clipboard.writeText(text).then(function() {\n                var btn = $('vc-copy-btn');\n                btn.classList.add('vc-copied');\n                btn.innerHTML = '<svg width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><polyline points=\"20 6 9 17 4 12\"\/><\/svg> Copied!';\n                setTimeout(function() {\n                    btn.classList.remove('vc-copied');\n                    btn.innerHTML = '<svg width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><rect x=\"9\" y=\"9\" width=\"13\" height=\"13\" rx=\"2\"\/><path d=\"M5 15H4a2 2 0 01-2-2V4a2 2 0 012-2h9a2 2 0 012 2v1\"\/><\/svg> Copy';\n                }, 2000);\n            });\n        }\n    });\n\n    \/* \u2500\u2500 SECTIONS \u2500\u2500 *\/\n    document.querySelectorAll('.vc-section-toggle').forEach(function(btn) {\n        btn.addEventListener('click', function() {\n            var section = this.closest('.vc-section');\n            var isOpen = section.classList.contains('vc-open');\n            section.classList.toggle('vc-open');\n            this.setAttribute('aria-expanded', !isOpen);\n        });\n    });\n\n    \/* \u2500\u2500 FAQ \u2500\u2500 *\/\n    var faqData = [\n        { q: 'What is vibration velocity?', a: '<p>Vibration velocity is the speed at which a vibrating surface moves back and forth, measured in mm\/s RMS (root mean square). It is the most widely used parameter for evaluating machine condition because it correlates well with vibration energy and the risk of mechanical damage.<\/p><p>ISO 10816 and ISO 20816 define permissible velocity limits organized by machine class and evaluation zone.<\/p>' },\n        { q: 'What is the difference between ISO 10816 and ISO 20816?', a: '<p>ISO 20816 is the modern replacement for ISO 10816. The zone boundaries and machine classes are essentially the same for housing (non-rotating parts) vibration evaluation.<\/p><p>ISO 20816 adds shaft vibration requirements and updated measurement practices. For broadband velocity RMS evaluation on machine housings \u2014 the most common industrial use \u2014 the classic ISO 10816 limits still apply.<\/p>' },\n        { q: 'How do I measure vibration velocity?', a: '<p>Vibration velocity is measured with an accelerometer or velocity sensor mounted on the machine bearing housing. The sensor signal is processed by a vibration analyzer to produce a broadband RMS velocity value in mm\/s.<\/p><p>Measurements should be taken in three directions: horizontal, vertical, and axial. The highest reading is used for zone evaluation. The standard frequency range is typically 10\u20131000 Hz.<\/p>' },\n        { q: 'What should I do if the machine is in Zone C or D?', a: '<p><strong>Zone C:<\/strong> Vibration is tolerable only for limited periods \u2014 plan corrective action soon.<\/p><p><strong>Zone D:<\/strong> Vibration is severe enough to cause damage \u2014 stop the machine immediately if possible and investigate the root cause.<\/p><p>Common corrective actions include: dynamic re-balancing, shaft alignment correction, bearing replacement, looseness repair, or addressing structural resonance.<\/p>' },\n        { q: 'Which sensor is best for vibration velocity measurement?', a: '<p>For most industrial machines, a piezoelectric accelerometer with integrated electronics (IEPE\/ICP type) is the standard choice \u2014 the acceleration signal is electronically integrated to velocity.<\/p><p>For low-frequency applications below 10 Hz, electrodynamic velocity sensors may be preferred. Ensure the sensor frequency range covers at least 10\u20131000 Hz per ISO 10816.<\/p>' }\n    ];\n\n    var faqList = $('vc-faq-list');\n    faqData.forEach(function(faq) {\n        faqList.innerHTML += '<div class=\"vc-faq-item\"><button type=\"button\" class=\"vc-faq-q\"><span>' + faq.q + '<\/span><svg class=\"vc-faq-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg><\/button><div class=\"vc-faq-a\"><div class=\"vc-faq-a-inner\">' + faq.a + '<\/div><\/div><\/div>';\n    });\n    faqList.addEventListener('click', function(e) {\n        var btn = e.target.closest('.vc-faq-q');\n        if (!btn) return;\n        btn.closest('.vc-faq-item').classList.toggle('vc-open');\n    });\n\n    \/* \u2500\u2500 HISTORY \u2500\u2500 *\/\n    function saveHistory(entry) {\n        var key = 'vc_history_' + SLUG;\n        var arr = [];\n        try { arr = JSON.parse(localStorage.getItem(key)) || []; } catch(e) {}\n        entry._ts = new Date().toISOString();\n        arr.unshift(entry);\n        if (arr.length > 10) arr = arr.slice(0, 10);\n        try { localStorage.setItem(key, JSON.stringify(arr)); } catch(e) {}\n    }\n\n    \/* \u2500\u2500 URL PARAMS \u2500\u2500 *\/\n    function loadParams() {\n        var p = new URLSearchParams(window.location.search);\n        p.forEach(function(v, k) { var el = $(k) || $('vc-' + k); if (el) el.value = v; });\n    }\n\n    \/* \u2500\u2500 KATEX \u2500\u2500 *\/\n    function renderFormulas() {\n        try {\n            katex.render('v_{RMS} = \\\\frac{1}{\\\\sqrt{2}} \\\\cdot v_{peak} \\\\quad [\\\\text{mm\/s}]', $('vc-katex-1'), { displayMode: true, throwOnError: false });\n        } catch(e) {}\n    }\n\n    \/* \u2500\u2500 INIT \u2500\u2500 *\/\n    function init() {\n        try {\n            var saved = localStorage.getItem('vc_units');\n            if (saved === 'imperial') {\n                unitSystem = 'imperial';\n                unitBtns.forEach(function(b) { b.classList.toggle('vc-active', b.getAttribute('data-system') === 'imperial'); });\n                $('vc-vel-unit-hint').textContent = '(in\/s RMS)';\n            }\n        } catch(e) {}\n\n        loadParams();\n        renderFormulas();\n        calculate();\n    }\n\n    if (document.readyState === 'loading') {\n        document.addEventListener('DOMContentLoaded', init);\n    } else {\n        init();\n    }\n})();\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>Kontroller tillatt vibrasjonshastighet i henhold til ISO 10816 \/ ISO 20816. Velg maskinklasse, skriv inn m\u00e5lt hastighet for \u00e5 f\u00e5 soneevaluering A\/B\/C\/D med fargekodede resultater.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"ai_generated_summary":"","footnotes":""},"categories":[],"tags":[],"class_list":["post-100302","calculator","type-calculator","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/vibromera.eu\/nb\/wp-json\/wp\/v2\/calculator\/100302","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vibromera.eu\/nb\/wp-json\/wp\/v2\/calculator"}],"about":[{"href":"https:\/\/vibromera.eu\/nb\/wp-json\/wp\/v2\/types\/calculator"}],"version-history":[{"count":2,"href":"https:\/\/vibromera.eu\/nb\/wp-json\/wp\/v2\/calculator\/100302\/revisions"}],"predecessor-version":[{"id":100734,"href":"https:\/\/vibromera.eu\/nb\/wp-json\/wp\/v2\/calculator\/100302\/revisions\/100734"}],"wp:attachment":[{"href":"https:\/\/vibromera.eu\/nb\/wp-json\/wp\/v2\/media?parent=100302"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vibromera.eu\/nb\/wp-json\/wp\/v2\/categories?post=100302"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vibromera.eu\/nb\/wp-json\/wp\/v2\/tags?post=100302"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}