{"id":100226,"date":"2026-02-15T20:28:20","date_gmt":"2026-02-15T20:28:20","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100226"},"modified":"2026-03-05T15:42:46","modified_gmt":"2026-03-05T15:42:46","slug":"shaft-vibration-iso7919","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/pt_br\/calculators\/shaft-vibration-iso7919\/","title":{"rendered":"Limites de vibra\u00e7\u00e3o relativa do eixo de acordo com a ISO 7919 | Vibromera"},"content":{"rendered":"\n<script type=\"application\/ld+json\">\n{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Shaft Relative Vibration Limits Calculator\",\"alternateName\":[\"ISO 7919 Calculator\",\"Proximity Probe Vibration Calculator\",\"Shaft Displacement Calculator\"],\"description\":\"Free online engineering calculator for shaft relative vibration evaluation per ISO 7919. Determine vibration zones A\/B\/C\/D for turbines, generators, and rotating machinery using proximity probe data.\",\"url\":\"https:\/\/vibromera.eu\/calculators\/shaft-vibration-iso7919\/\",\"applicationCategory\":\"Engineering Calculator\",\"operatingSystem\":\"Any (Web Browser)\",\"offers\":{\"@type\":\"Offer\",\"price\":\"0\",\"priceCurrency\":\"EUR\"},\"creator\":{\"@type\":\"Organization\",\"name\":\"Vibromera\",\"url\":\"https:\/\/vibromera.eu\/\"},\"datePublished\":\"2025-01-01\",\"dateModified\":\"2025-02-15\",\"inLanguage\":\"en\",\"isAccessibleForFree\":true,\"featureList\":[\"ISO 7919 zone classification\",\"Multiple machine types\",\"Speed-dependent limits\",\"Shaft orbit information\",\"Auto-calculation on input change\",\"URL parameter sharing\",\"Calculation history\"],\"keywords\":\"shaft vibration, ISO 7919, proximity probe, shaft displacement, vibration zone\"}\n<\/script>\n\n<script type=\"application\/ld+json\">\n{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[\n{\"@type\":\"Question\",\"name\":\"What is shaft relative vibration?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Shaft relative vibration is the dynamic displacement of a rotating shaft measured relative to its bearing housing, typically using non-contact proximity (eddy current) probes. It is expressed in micrometers peak-to-peak (\u03bcm p-p) and captures shaft motion that bearing-mounted sensors may miss.\"}},\n{\"@type\":\"Question\",\"name\":\"What is the difference between proximity probes and accelerometers?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Proximity probes (eddy current sensors) measure shaft displacement relative to the bearing housing without contact. Accelerometers measure absolute bearing housing vibration. Proximity probes are essential for fluid-film bearing machines where shaft motion may not transmit fully to the housing.\"}},\n{\"@type\":\"Question\",\"name\":\"What is the difference between ISO 7919 and ISO 20816?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"ISO 7919 covers shaft relative vibration measured by proximity probes. ISO 20816 (which replaced ISO 10816) covers bearing housing vibration measured by accelerometers or velocity sensors. Both use zone classification A\/B\/C\/D but measure different quantities.\"}},\n{\"@type\":\"Question\",\"name\":\"What is a shaft orbit?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"A shaft orbit is the two-dimensional path traced by the shaft centerline during rotation, constructed from two orthogonal proximity probes (typically X-Y). Orbit shape helps diagnose faults: circular orbits suggest unbalance, figure-8 patterns suggest misalignment, and banana shapes suggest rub.\"}},\n{\"@type\":\"Question\",\"name\":\"What is acceptable shaft displacement?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Acceptable displacement depends on machine type and speed per ISO 7919. For general machinery at 3000 RPM, Zone A (newly commissioned) is typically \u226450 \u03bcm p-p, Zone B (acceptable for long-term operation) is \u2264100 \u03bcm p-p. Higher speeds generally require tighter limits.\"}}\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\":\"Shaft Vibration ISO 7919\",\"item\":\"https:\/\/vibromera.eu\/calculators\/shaft-vibration-iso7919\/\"}\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 ul { margin:4px 0 8px 16px; padding:0; }\n.vc-faq-a-inner li { margin-bottom:3px; }\n\n\/* \u2500\u2500 RELATED \u2500\u2500 *\/\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\/* \u2500\u2500 PROMO \u2500\u2500 *\/\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\/* \u2500\u2500 FOOTER \u2500\u2500 *\/\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\/* \u2500\u2500 PRINT \u2500\u2500 *\/\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-shaft-vibration\">\n\n<!-- Header -->\n<header class=\"vc-header\">\n    <p class=\"vc-header-eyebrow\">Free Engineering Tool #027<\/p>\n    <h1 class=\"vc-header-title\">Shaft Relative Vibration Limits<\/h1>\n    <p class=\"vc-header-subtitle\">Evaluate shaft relative vibration measured by proximity probes per ISO 7919 series. Determine vibration zone (A\/B\/C\/D) for turbines, generators, and rotating machinery.<\/p>\n    <div class=\"vc-badges\">\n        <span class=\"vc-badge\">ISO 7919<\/span>\n        <span class=\"vc-badge\">Proximity Probes<\/span>\n        <span class=\"vc-badge\">Zone A\u2013D<\/span>\n    <\/div>\n<\/header>\n\n<!-- Calculator Card -->\n<div class=\"vc-card\">\n    <form class=\"vc-form\" id=\"vc-form\" autocomplete=\"off\">\n        <div class=\"vc-form-grid\">\n            <div class=\"vc-field vc-field-full\">\n                <label class=\"vc-label\" for=\"vc-machine\">Machine Type<\/label>\n                <select class=\"vc-select\" id=\"vc-machine\">\n                    <option value=\"general\" selected>General rotating machinery (\u226510 MW)<\/option>\n                    <option value=\"steam\">Steam turbine \/ generator set<\/option>\n                    <option value=\"gas\">Gas turbine<\/option>\n                    <option value=\"hydro\">Hydraulic turbine \/ generator<\/option>\n                    <option value=\"recip\">Reciprocating machine<\/option>\n                <\/select>\n            <\/div>\n            <div class=\"vc-field\">\n                <label class=\"vc-label\" for=\"vc-speed\">Shaft Speed <span class=\"vc-label-hint\">(RPM)<\/span><\/label>\n                <input class=\"vc-input\" type=\"number\" id=\"vc-speed\" inputmode=\"decimal\" step=\"any\" min=\"1\" placeholder=\"e.g. 3000\" value=\"3000\">\n            <\/div>\n            <div class=\"vc-field\">\n                <label class=\"vc-label\" for=\"vc-disp\">Measured Shaft Displacement <span class=\"vc-label-hint\">(\u03bcm p-p)<\/span><\/label>\n                <input class=\"vc-input\" type=\"number\" id=\"vc-disp\" inputmode=\"decimal\" step=\"any\" min=\"0\" placeholder=\"e.g. 75\" value=\"75\">\n            <\/div>\n        <\/div>\n\n        <!-- Presets -->\n        <div class=\"vc-presets\">\n            <div class=\"vc-presets-label\">Quick presets<\/div>\n            <button type=\"button\" class=\"vc-preset-btn\" data-machine=\"steam\" data-speed=\"3000\" data-disp=\"75\">Turbine 3000 RPM \/ 75 \u03bcm<\/button>\n            <button type=\"button\" class=\"vc-preset-btn\" data-machine=\"steam\" data-speed=\"1500\" data-disp=\"45\">Generator 1500 RPM \/ 45 \u03bcm<\/button>\n            <button type=\"button\" class=\"vc-preset-btn\" data-machine=\"hydro\" data-speed=\"300\" data-disp=\"120\">Hydro 300 RPM \/ 120 \u03bcm<\/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-r-zone-card\">\n                <div class=\"vc-rcard-label\">Vibration Zone (ISO 7919)<\/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\">Measured Displacement<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-disp\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Zone A\/B Boundary<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-ab\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Zone B\/C Boundary<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-bc\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Zone C\/D Boundary<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-cd\">\u2014<\/div>\n            <\/div>\n        <\/div>\n\n        <!-- Zone Boundary Table -->\n        <div id=\"vc-zone-table-wrap\"><\/div>\n\n        <!-- Orbit Info -->\n        <div class=\"vc-info-box\" style=\"margin-top:14px;\">\n            <p><strong>Shaft Orbit Note:<\/strong> This calculator evaluates single-axis (S<sub>max<\/sub>) peak-to-peak displacement. For full shaft orbit analysis, two orthogonal proximity probes (X-Y) are required. The orbit shape provides additional diagnostic information \u2014 circular orbits suggest unbalance, figure-8 patterns suggest misalignment.<\/p>\n        <\/div>\n    <\/div>\n<\/div>\n\n<!-- Theory & Reference -->\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; Formulas<\/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>ISO 7919 \u2014 Shaft Relative Vibration<\/h3>\n            <p>ISO 7919 defines evaluation criteria for shaft relative vibration measured by non-contact proximity probes (eddy current sensors). The vibration is expressed as peak-to-peak shaft displacement in micrometers (\u03bcm p-p).<\/p>\n\n            <h3>Speed-Dependent Zone Boundaries<\/h3>\n            <p>Zone boundaries depend on shaft rotational speed. The general relationship follows:<\/p>\n            <div class=\"vc-formula-box\" id=\"vc-katex-1\"><\/div>\n            <p>Where <strong>n<\/strong> is the shaft speed in RPM and <strong>A<\/strong> is a coefficient that differs for each zone boundary and machine type.<\/p>\n\n            <h3>Zone Classification<\/h3>\n            <table class=\"vc-table\">\n                <thead><tr><th>Zone<\/th><th>Description<\/th><th>Action<\/th><\/tr><\/thead>\n                <tbody>\n                    <tr><td class=\"vc-zone-cell-a\">A<\/td><td>Newly commissioned machines<\/td><td>Normal \u2014 no action required<\/td><\/tr>\n                    <tr><td class=\"vc-zone-cell-b\">B<\/td><td>Acceptable for long-term operation<\/td><td>Monitor \u2014 normal operation<\/td><\/tr>\n                    <tr><td class=\"vc-zone-cell-c\">C<\/td><td>Not acceptable for long-term<\/td><td>Plan maintenance \u2014 investigate cause<\/td><\/tr>\n                    <tr><td class=\"vc-zone-cell-d\">D<\/td><td>Damage may occur<\/td><td>Immediate action \u2014 shutdown if necessary<\/td><\/tr>\n                <\/tbody>\n            <\/table>\n\n            <h3>Simplified Zone Boundaries by Machine Type<\/h3>\n            <table class=\"vc-table\">\n                <thead><tr><th>Machine Type<\/th><th>A\/B (\u03bcm p-p)<\/th><th>B\/C (\u03bcm p-p)<\/th><th>C\/D (\u03bcm p-p)<\/th><th>Typical Speed<\/th><\/tr><\/thead>\n                <tbody>\n                    <tr><td>General (\u226510 MW)<\/td><td>50<\/td><td>100<\/td><td>170<\/td><td>1000\u20133000 RPM<\/td><\/tr>\n                    <tr><td>Steam turbine\/generator<\/td><td>50<\/td><td>100<\/td><td>170<\/td><td>1500\u20133600 RPM<\/td><\/tr>\n                    <tr><td>Gas turbine<\/td><td>50<\/td><td>100<\/td><td>170<\/td><td>3000\u201315000 RPM<\/td><\/tr>\n                    <tr><td>Hydro turbine\/generator<\/td><td>80<\/td><td>160<\/td><td>260<\/td><td>75\u2013750 RPM<\/td><\/tr>\n                    <tr><td>Reciprocating<\/td><td>80<\/td><td>160<\/td><td>260<\/td><td>200\u20131000 RPM<\/td><\/tr>\n                <\/tbody>\n            <\/table>\n\n            <h3>Practical Example<\/h3>\n            <div class=\"vc-example-box\">\n                <div class=\"vc-example-title\">Example \u2014 Steam Turbine at 3000 RPM<\/div>\n                <p><strong>Given:<\/strong> Steam turbine, speed = 3000 RPM, measured shaft displacement = 75 \u03bcm p-p<\/p>\n                <p>Zone boundaries: A\/B = 50 \u03bcm, B\/C = 100 \u03bcm, C\/D = 170 \u03bcm<\/p>\n                <p>75 \u03bcm > 50 \u03bcm (A\/B) and \u2264 100 \u03bcm (B\/C)<\/p>\n                <p>Result: <strong>Zone B<\/strong> \u2014 Acceptable for long-term operation<\/p>\n            <\/div>\n\n            <div class=\"vc-warning-box\">\n                <p style=\"margin:0;font-size:14px;color:var(--vc-ink-secondary);\"><strong>\u26a0\ufe0f Note:<\/strong> This calculator uses simplified zone boundaries from ISO 7919-1 (general guidelines). The actual ISO 7919 series (parts 2\u20135) provides speed-dependent curves for specific machine types. Always consult the relevant part of ISO 7919 for contractual or warranty evaluations.<\/p>\n            <\/div>\n        <\/div>\n    <\/div>\n<\/div>\n\n<!-- Related Calculators -->\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\/vibration-velocity\/\">Vibration Velocity (ISO 10816)<\/a>\n                <a class=\"vc-related-link\" href=\"\/calculators\/residual-unbalance-iso1940\/\">Residual Unbalance (ISO 1940)<\/a>\n                <a class=\"vc-related-link\" href=\"\/calculators\/vibration-source-identifier\/\">Vibration Source Identifier<\/a>\n                <a class=\"vc-related-link\" href=\"\/calculators\/vibration-trend-remaining-life\/\">Remaining Life Estimator<\/a>\n                <a class=\"vc-related-link\" href=\"\/calculators\/shaft-radial-runout\/\">Shaft Radial Runout<\/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 and vibration monitoring. Proximity probe integration for shaft vibration. 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 -->\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 7919 series. 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 = 'shaft-vibration-iso7919';\n\n    function $(id) { return document.getElementById(id); }\n    function fmt(n, d) { if(isNaN(n)) return '\u2014'; var f=n.toFixed(d===undefined?2:d); return f.replace(\/(\\.\\d*?)0+$\/,'$1').replace(\/\\.$\/,''); }\n\n    \/* \u2500\u2500 ZONE BOUNDARIES (\u03bcm p-p) \u2014 simplified from ISO 7919-1 \u2500\u2500 *\/\n    \/* Coefficients A for S_max = A \u00d7 sqrt(n), clamped with min\/max *\/\n    var ZONES = {\n        general: {\n            label: 'General rotating (\u226510 MW)',\n            ab: function(n) { return Math.max(50, Math.min(90, 0.9 * Math.sqrt(n))); },\n            bc: function(n) { return Math.max(100, Math.min(180, 1.8 * Math.sqrt(n))); },\n            cd: function(n) { return Math.max(170, Math.min(290, 3.1 * Math.sqrt(n))); }\n        },\n        steam: {\n            label: 'Steam turbine \/ generator',\n            ab: function(n) { return Math.max(50, Math.min(90, 0.9 * Math.sqrt(n))); },\n            bc: function(n) { return Math.max(100, Math.min(180, 1.8 * Math.sqrt(n))); },\n            cd: function(n) { return Math.max(170, Math.min(290, 3.1 * Math.sqrt(n))); }\n        },\n        gas: {\n            label: 'Gas turbine',\n            ab: function(n) { return Math.max(37, Math.min(80, 0.7 * Math.sqrt(n))); },\n            bc: function(n) { return Math.max(75, Math.min(160, 1.4 * Math.sqrt(n))); },\n            cd: function(n) { return Math.max(130, Math.min(260, 2.4 * Math.sqrt(n))); }\n        },\n        hydro: {\n            label: 'Hydro turbine \/ generator',\n            ab: function(n) { return Math.max(80, Math.min(200, 4.5 * Math.sqrt(n))); },\n            bc: function(n) { return Math.max(160, Math.min(400, 9.0 * Math.sqrt(n))); },\n            cd: function(n) { return Math.max(260, Math.min(600, 15.0 * Math.sqrt(n))); }\n        },\n        recip: {\n            label: 'Reciprocating machine',\n            ab: function(n) { return Math.max(80, Math.min(180, 3.6 * Math.sqrt(n))); },\n            bc: function(n) { return Math.max(160, Math.min(360, 7.2 * Math.sqrt(n))); },\n            cd: function(n) { return Math.max(260, Math.min(550, 12.0 * Math.sqrt(n))); }\n        }\n    };\n\n    \/* \u2500\u2500 CALCULATION \u2500\u2500 *\/\n    function calculate() {\n        var machineType = $('vc-machine').value;\n        var speed = parseFloat($('vc-speed').value);\n        var disp = parseFloat($('vc-disp').value);\n\n        if (!speed || speed <= 0 || isNaN(disp) || disp < 0) {\n            $('vc-results').classList.remove('vc-visible');\n            return;\n        }\n\n        var z = ZONES[machineType];\n        var ab = z.ab(speed);\n        var bc = z.bc(speed);\n        var cd = z.cd(speed);\n\n        \/\/ Determine zone\n        var zone, zoneDesc, zoneClass, zoneAction;\n        if (disp <= ab) {\n            zone = 'A'; zoneDesc = 'Newly commissioned \u2014 Excellent'; zoneClass = 'vc-zone-a'; zoneAction = 'No action required';\n        } else if (disp <= bc) {\n            zone = 'B'; zoneDesc = 'Acceptable for long-term operation'; zoneClass = 'vc-zone-b'; zoneAction = 'Monitor \u2014 normal operation';\n        } else if (disp <= cd) {\n            zone = 'C'; zoneDesc = 'Not acceptable for long-term'; zoneClass = 'vc-zone-c'; zoneAction = 'Plan maintenance \u2014 investigate';\n        } else {\n            zone = 'D'; zoneDesc = 'Damage may occur'; zoneClass = 'vc-zone-d'; zoneAction = 'Immediate action \u2014 shutdown';\n        }\n\n        \/\/ Display results\n        var zoneCard = $('vc-r-zone-card');\n        zoneCard.className = 'vc-rcard vc-rcard-primary ' + zoneClass;\n        $('vc-r-zone').innerHTML = 'Zone ' + zone + ' <span class=\"vc-rcard-unit\">\u2014 ' + zoneDesc + '<\/span>';\n        $('vc-r-disp').innerHTML = fmt(disp, 1) + ' <span class=\"vc-rcard-unit\">\u03bcm p-p<\/span>';\n        $('vc-r-ab').innerHTML = fmt(ab, 0) + ' <span class=\"vc-rcard-unit\">\u03bcm p-p<\/span>';\n        $('vc-r-bc').innerHTML = fmt(bc, 0) + ' <span class=\"vc-rcard-unit\">\u03bcm p-p<\/span>';\n        $('vc-r-cd').innerHTML = fmt(cd, 0) + ' <span class=\"vc-rcard-unit\">\u03bcm p-p<\/span>';\n\n        \/\/ Zone boundary table\n        var tableHTML = '<table class=\"vc-zone-table\">' +\n            '<thead><tr><th>Zone<\/th><th>Range (\u03bcm p-p)<\/th><th>Status<\/th><th>Action<\/th><\/tr><\/thead><tbody>' +\n            '<tr class=\"' + (zone === 'A' ? 'vc-zone-highlight' : '') + '\"><td class=\"vc-zone-cell-a\">A<\/td><td>\u2264 ' + fmt(ab, 0) + '<\/td><td>Newly commissioned<\/td><td>No action<\/td><\/tr>' +\n            '<tr class=\"' + (zone === 'B' ? 'vc-zone-highlight' : '') + '\"><td class=\"vc-zone-cell-b\">B<\/td><td>' + fmt(ab, 0) + ' \u2013 ' + fmt(bc, 0) + '<\/td><td>Long-term acceptable<\/td><td>Monitor<\/td><\/tr>' +\n            '<tr class=\"' + (zone === 'C' ? 'vc-zone-highlight' : '') + '\"><td class=\"vc-zone-cell-c\">C<\/td><td>' + fmt(bc, 0) + ' \u2013 ' + fmt(cd, 0) + '<\/td><td>Not acceptable long-term<\/td><td>Plan maintenance<\/td><\/tr>' +\n            '<tr class=\"' + (zone === 'D' ? 'vc-zone-highlight' : '') + '\"><td class=\"vc-zone-cell-d\">D<\/td><td>> ' + fmt(cd, 0) + '<\/td><td>Damage risk<\/td><td>Immediate action<\/td><\/tr>' +\n            '<\/tbody><\/table>';\n        $('vc-zone-table-wrap').innerHTML = tableHTML;\n\n        $('vc-results').classList.add('vc-visible');\n\n        \/\/ URL params\n        var u = new URL(window.location);\n        u.searchParams.set('machine', machineType);\n        u.searchParams.set('speed', speed);\n        u.searchParams.set('disp', disp);\n        history.replaceState(null, '', u.toString());\n\n        \/\/ History\n        saveHistory({\n            machine: machineType,\n            speed: speed,\n            disp: disp,\n            zone: zone,\n            _summary: z.label + ', n=' + speed + ' RPM, S=' + disp + ' \u03bcm \u2192 Zone ' + zone\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            $('vc-machine').value = this.getAttribute('data-machine');\n            $('vc-speed').value = this.getAttribute('data-speed');\n            $('vc-disp').value = this.getAttribute('data-disp');\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 = 'Shaft Relative Vibration \u2014 ISO 7919\\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: ' + $('vc-machine').options[$('vc-machine').selectedIndex].text + '\\n' +\n            'Speed: ' + $('vc-speed').value + ' RPM\\n' +\n            'Measured displacement: ' + $('vc-disp').value + ' \u03bcm p-p\\n' +\n            'Zone: ' + $('vc-r-zone').textContent + '\\n' +\n            'A\/B boundary: ' + $('vc-r-ab').textContent + '\\n' +\n            'B\/C boundary: ' + $('vc-r-bc').textContent + '\\n' +\n            'C\/D boundary: ' + $('vc-r-cd').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\/shaft-vibration-iso7919\/';\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 COLLAPSIBLE 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 shaft relative vibration?', a: '<p>Shaft relative vibration is the dynamic displacement of a rotating shaft measured relative to its bearing housing, typically using non-contact proximity (eddy current) probes. It is expressed in micrometers peak-to-peak (\u03bcm p-p).<\/p><p>This measurement captures shaft motion that bearing-mounted sensors may miss, making it essential for machines with fluid-film (journal) bearings where the shaft can vibrate without transmitting proportional motion to the housing.<\/p>' },\n        { q: 'What is the difference between proximity probes and accelerometers?', a: '<p><strong>Proximity probes<\/strong> (eddy current sensors) are non-contact sensors mounted in the bearing housing that measure shaft displacement relative to the housing. They provide DC position (shaft centerline) and dynamic vibration.<\/p><p><strong>Accelerometers<\/strong> are contact sensors mounted on the bearing housing that measure absolute housing vibration (acceleration, integrated to velocity).<\/p><ul><li>Proximity probes: best for fluid-film bearing machines (turbines, large compressors)<\/li><li>Accelerometers: best for rolling element bearing machines (motors, pumps, fans)<\/li><\/ul>' },\n        { q: 'What is the difference between ISO 7919 and ISO 20816?', a: '<p><strong>ISO 7919<\/strong> covers shaft relative vibration measured by proximity probes (displacement, \u03bcm p-p).<\/p><p><strong>ISO 20816<\/strong> (which replaced ISO 10816) covers bearing housing vibration measured by accelerometers or velocity sensors (velocity in mm\/s RMS or displacement).<\/p><p>Both use the same zone classification system (A\/B\/C\/D) but measure fundamentally different quantities. For critical machinery with journal bearings, both measurements are typically required.<\/p>' },\n        { q: 'What is a shaft orbit?', a: '<p>A shaft orbit is the two-dimensional path traced by the shaft centerline during rotation. It is constructed from two orthogonal proximity probes mounted 90\u00b0 apart (X-Y configuration).<\/p><p>Orbit shapes provide diagnostic information:<\/p><ul><li><strong>Circular orbit:<\/strong> Unbalance (1\u00d7 synchronous)<\/li><li><strong>Elliptical orbit:<\/strong> Normal, slight anisotropy in bearing stiffness<\/li><li><strong>Figure-8:<\/strong> Misalignment (2\u00d7 component dominant)<\/li><li><strong>Banana\/loop:<\/strong> Rub or clearance issues<\/li><li><strong>Erratic\/unstable:<\/strong> Oil whirl\/whip, fluid-induced instability<\/li><\/ul>' },\n        { q: 'What is acceptable shaft displacement?', a: '<p>Acceptable displacement depends on machine type, size, and rotational speed per ISO 7919:<\/p><ul><li><strong>Zone A (\u226450 \u03bcm at 3000 RPM):<\/strong> Typical of newly commissioned machines in excellent condition<\/li><li><strong>Zone B (50\u2013100 \u03bcm at 3000 RPM):<\/strong> Acceptable for unrestricted long-term operation<\/li><li><strong>Zone C (100\u2013170 \u03bcm at 3000 RPM):<\/strong> Not acceptable for continuous operation \u2014 investigate and plan corrective action<\/li><li><strong>Zone D (>170 \u03bcm at 3000 RPM):<\/strong> Risk of damage \u2014 take immediate action<\/li><\/ul><p>For slower machines (e.g., hydro turbines at 300 RPM), boundaries are typically higher because larger shafts naturally exhibit more displacement.<\/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        if (p.has('machine')) $('vc-machine').value = p.get('machine');\n        if (p.has('speed')) $('vc-speed').value = p.get('speed');\n        if (p.has('disp')) $('vc-disp').value = p.get('disp');\n    }\n\n    \/* \u2500\u2500 KATEX \u2500\u2500 *\/\n    function renderFormulas() {\n        try {\n            katex.render('S_{\\\\max} = A \\\\times \\\\sqrt{n} \\\\quad [\\\\mu m \\\\; p\\\\text{-}p]', $('vc-katex-1'), { displayMode: true, throwOnError: false });\n        } catch(e) {}\n    }\n\n    \/* \u2500\u2500 INIT \u2500\u2500 *\/\n    function init() {\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>Calculadora online gratuita para limites de vibra\u00e7\u00e3o relativa em eixos, de acordo com a norma ISO 7919. Avalie medi\u00e7\u00f5es com sonda de proximidade, determine a zona de vibra\u00e7\u00e3o (A\/B\/C\/D) e verifique a conformidade para turbinas, geradores e m\u00e1quinas rotativas.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"ai_generated_summary":"","footnotes":""},"categories":[],"tags":[],"class_list":["post-100226","calculator","type-calculator","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/calculator\/100226","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/calculator"}],"about":[{"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/types\/calculator"}],"version-history":[{"count":2,"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/calculator\/100226\/revisions"}],"predecessor-version":[{"id":100773,"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/calculator\/100226\/revisions\/100773"}],"wp:attachment":[{"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/media?parent=100226"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/categories?post=100226"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/tags?post=100226"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}