{"id":30,"date":"2026-10-13T01:29:26","date_gmt":"2026-10-13T01:29:26","guid":{"rendered":"https:\/\/fgvhp.com\/tools\/isolator-leak-rate-calculator\/"},"modified":"2026-10-13T01:29:26","modified_gmt":"2026-10-13T01:29:26","slug":"isolator-leak-rate-calculator","status":"publish","type":"page","link":"https:\/\/fgvhp.com\/ru\/tools\/isolator-leak-rate-calculator\/","title":{"rendered":"\u041a\u0430\u043b\u044c\u043a\u0443\u043b\u044f\u0442\u043e\u0440 \u0441\u043a\u043e\u0440\u043e\u0441\u0442\u0438 \u0443\u0442\u0435\u0447\u043a\u0438 \u0438\u0437\u043e\u043b\u044f\u0442\u043e\u0440\u0430 (ISO 10648-2)"},"content":{"rendered":"\n\n<section class=\"phero\"><div class=\"wrap\">\n  <div class=\"crumb\"><a href=\"\/\">Home<\/a> \/ <a href=\"\/tools\/\">Tools<\/a> \/ <span>Isolator leak rate calculator<\/span><\/div>\n  <span class=\"mono eyebrow\">Isolators \u00b7 Calculator<\/span>\n  <h1>Isolator Leak Rate Calculator (ISO 10648-2)<\/h1>\n  <p class=\"lead\">Turn a pressure decay reading into an hourly leak rate and ISO 10648-2 leak-tightness class, with temperature correction. Enter your start and end pressure, the measurement time and the chamber temperature.<\/p>\n<\/div><\/section>\n<section class=\"fgv-sec\" style=\"padding-top:40px\"><div class=\"wrap\">\n  <div class=\"tool\" data-tool=\"leak\"><noscript><p>This calculator needs JavaScript. The method is described below.<\/p><\/noscript><\/div>\n  <p class=\"note\" style=\"margin-top:14px\">Engineering estimate only. Confirm by testing and validation for your equipment and load.<\/p>\n<\/div><\/section>\n<section class=\"fgv-sec alt\"><div class=\"wrap narrow\"><div class=\"art\"><h2>How the calculation works<\/h2>\n<p>ISO 10648-2 classifies containment enclosures by their <strong>hourly leak rate<\/strong> T<sub>f<\/sub>: the volume of gas that leaks in one hour divided by the volume of the enclosure. Because the enclosure volume is fixed, the fraction of gas lost (or gained) during a pressure decay test can be found from the ideal gas law using absolute pressures and absolute temperatures:<\/p>\n<div class=\"keyp\" style=\"font-family:'IBM Plex Mono',monospace\"><b>Formula<\/b>T<sub>f<\/sub> = | 1 \u2212 (P<sub>2<\/sub> \u00b7 T<sub>1<\/sub>) \/ (P<sub>1<\/sub> \u00b7 T<sub>2<\/sub>) | \u00d7 60 \/ t<br><small style=\"font-family:'IBM Plex Sans',sans-serif\">P = absolute pressure (atmospheric + gauge), T = absolute temperature in K, t = measurement time in minutes, T<sub>f<\/sub> in h<sup>\u22121<\/sup><\/small><\/div>\n<p>The result is compared with the class limits:<\/p>\n<table><thead><tr><th>ISO 10648-2 class<\/th><th>Hourly leak rate T<sub>f<\/sub><\/th><\/tr><\/thead><tbody>\n<tr><th>Class 1<\/th><td>\u2264 5 \u00d7 10<sup>\u22124<\/sup> h<sup>\u22121<\/sup><\/td><\/tr>\n<tr><th>Class 2<\/th><td>\u2264 2.5 \u00d7 10<sup>\u22123<\/sup> h<sup>\u22121<\/sup><\/td><\/tr>\n<tr><th>Class 3<\/th><td>\u2264 10<sup>\u22122<\/sup> h<sup>\u22121<\/sup><\/td><\/tr>\n<tr><th>Class 4<\/th><td>\u2264 10<sup>\u22121<\/sup> h<sup>\u22121<\/sup><\/td><\/tr>\n<\/tbody><\/table>\n<h2>Why temperature matters so much<\/h2>\n<p>At around 20 \u00b0C, a change of 0.1 \u00b0C in the chamber air changes the absolute pressure by roughly 35 Pa. Over a 30-minute test, Class 1 allows a drop of only about 25 Pa. A chamber that is cooling slightly can make a leaking isolator look tight under positive pressure; one that is warming can make a tight isolator fail. That is why the calculator asks for the temperature at both ends, and why a stabilisation period before the measurement is essential.<\/p>\n<h2>Limits of this calculator<\/h2>\n<ul>\n<li>It assumes the enclosure volume does not change. Gloves and flexible panels that move during the test add error.<\/li>\n<li>Gauge readings are relative to atmospheric pressure. A change in barometric pressure during the test is not corrected here.<\/li>\n<li>It is an engineering check, not a qualification record. Formal testing follows the method, test pressure and acceptance criteria in your URS and protocol.<\/li>\n<\/ul>\n<p>For the full method see <a href=\"https:\/\/fenggu-bio.com\/isolator-leak-test-pressure-decay\/\" target=\"_blank\" rel=\"noopener\">isolator leak testing by pressure decay<\/a>; gloves are tested separately \u2014 see <a href=\"\/vhp-knowledge\/isolator-glove-integrity-testing\/\">isolator glove integrity testing<\/a>.<\/p><\/div><\/div><\/section>\n\n<section class=\"fgv-sec\"><div class=\"wrap narrow\">\n  <span class=\"mono eyebrow\">FAQ<\/span><h2>Common questions<\/h2>\n  <div class=\"faq\"><details><summary>How do I calculate isolator leak rate from a pressure decay test?<\/summary><p>Convert the start and end gauge pressures to absolute pressure, apply the ideal gas law with the start and end temperatures, take the fraction of gas lost and scale it to one hour: Tf = |1 \u2212 (P2\u00b7T1)\/(P1\u00b7T2)| \u00d7 60 \/ t, with t in minutes.<\/p><\/details><details><summary>What leak rate does ISO 10648-2 Class 2 allow?<\/summary><p>Class 2 allows an hourly leak rate up to 2.5 \u00d7 10\u207b\u00b3 h\u207b\u00b9. Over a 30-minute test at about 500 Pa this is a drop of roughly 127 Pa.<\/p><\/details><details><summary>Why does the calculator need temperature?<\/summary><p>Because a temperature change shifts the pressure of the enclosed air. A 0.1 \u00b0C change is about 35 Pa, which is larger than the whole Class 1 allowance over 30 minutes.<\/p><\/details><details><summary>Can I use the calculator for a negative pressure test?<\/summary><p>Yes. Enter the gauge pressures as negative values. The calculator uses the magnitude of the change in gas quantity, so the result is valid for both positive and negative tests.<\/p><\/details><\/div>\n<\/div><\/section>\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"How do I calculate isolator leak rate from a pressure decay test?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Convert the start and end gauge pressures to absolute pressure, apply the ideal gas law with the start and end temperatures, take the fraction of gas lost and scale it to one hour: Tf = |1 \u2212 (P2\u00b7T1)\/(P1\u00b7T2)| \u00d7 60 \/ t, with t in minutes.\"}},{\"@type\":\"Question\",\"name\":\"What leak rate does ISO 10648-2 Class 2 allow?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Class 2 allows an hourly leak rate up to 2.5 \u00d7 10\u207b\u00b3 h\u207b\u00b9. Over a 30-minute test at about 500 Pa this is a drop of roughly 127 Pa.\"}},{\"@type\":\"Question\",\"name\":\"Why does the calculator need temperature?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Because a temperature change shifts the pressure of the enclosed air. A 0.1 \u00b0C change is about 35 Pa, which is larger than the whole Class 1 allowance over 30 minutes.\"}},{\"@type\":\"Question\",\"name\":\"Can I use the calculator for a negative pressure test?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. Enter the gauge pressures as negative values. The calculator uses the magnitude of the change in gas quantity, so the result is valid for both positive and negative tests.\"}}]}<\/script>\n<section class=\"fgv-sec\" style=\"padding-top:0\"><div class=\"wrap\"><p>More tools: <a class=\"go\" href=\"\/tools\/vhp-aeration-time-calculator\/\">VHP aeration time calculator<\/a> \u00b7 <a class=\"go\" href=\"\/tools\/vhp-equipment-selector\/\">VHP equipment selector<\/a><\/p><\/div><\/section>\n\n<section class=\"fgv-sec\" style=\"padding-top:0\"><div class=\"wrap\"><div class=\"cta\">\n  <div><span class=\"mono eyebrow\">Free application review<\/span><h2>Send your numbers to an engineer<\/h2><p>Use the button under the result to fill this form, or describe your space and equipment. An engineer reviews it and replies.<\/p><\/div>\n  <div><div class='fluentform ff-default fluentform_wrapper_1 ffs_default_wrap'><form data-form_id=\"1\" id=\"fluentform_1\" class=\"frm-fluent-form fluent_form_1 ff-el-form-top ff_form_instance_1_1 ff-form-loading ffs_default\" data-form_instance=\"ff_form_instance_1_1\" method=\"POST\" data-turnstile_key=\"0x4AAAAAAFR_A6IRFH-zWvr4\" ><fieldset  style=\"border: none!important;margin: 0!important;padding: 0!important;background-color: transparent!important;box-shadow: none!important;outline: none!important; min-inline-size: 100%;\">\n                    <legend class=\"ff_screen_reader_title\" style=\"display: block; margin: 0!important;padding: 0!important;height: 0!important;text-indent: -999999px;width: 0!important;overflow:hidden;\">Contact Form Demo<\/legend>        <div\n                style=\"display: none!important; position: absolute!important; transform: translateX(1000%)!important;\"\n                class=\"ff-el-group ff-hpsf-container\"\n        >\n            <div class=\"ff-el-input--label asterisk-right\">\n                <label for=\"ff_1_item_sf\" aria-label=\"Contact\">\n                    Contact                <\/label>\n            <\/div>\n            <div class=\"ff-el-input--content\">\n                <input type=\"text\"\n                       name=\"item_1__fluent_sf\"\n                       class=\"ff-el-form-control\"\n                       id=\"ff_1_item_sf\"\n                \/>\n            <\/div>\n        <\/div>\n        <input type='hidden' name='__fluent_form_embded_post_id' value='30' \/><input type=\"hidden\" id=\"_fluentform_1_fluentformnonce\" name=\"_fluentform_1_fluentformnonce\" value=\"8a489a4647\" \/><input type=\"hidden\" name=\"_wp_http_referer\" value=\"\/ru\/wp-json\/wp\/v2\/pages\/30\" \/><div data-type=\"name-element\" data-name=\"names\" class=\" ff-field_container ff-name-field-wrapper\" ><div class='ff-t-container'><div class='ff-t-cell '><div class='ff-el-group'><div class=\"ff-el-input--label asterisk-right\"><label for='ff_1_names_first_name_' id='label_ff_1_names_first_name_' >First Name<\/label><\/div><div class='ff-el-input--content'><input type=\"text\" name=\"names[first_name]\" id=\"ff_1_names_first_name_\" class=\"ff-el-form-control\" placeholder=\"First Name\" aria-invalid=\"false\" aria-required=false><\/div><\/div><\/div><div class='ff-t-cell '><div class='ff-el-group'><div class=\"ff-el-input--label asterisk-right\"><label for='ff_1_names_last_name_' id='label_ff_1_names_last_name_' >Last Name<\/label><\/div><div class='ff-el-input--content'><input type=\"text\" name=\"names[last_name]\" id=\"ff_1_names_last_name_\" class=\"ff-el-form-control\" placeholder=\"Last Name\" aria-invalid=\"false\" aria-required=false><\/div><\/div><\/div><\/div><\/div><div class='ff-el-group'><div class=\"ff-el-input--label ff-el-is-required asterisk-right\"><label for='ff_1_email' id='label_ff_1_email' aria-label=\"Email\">Email<\/label><\/div><div class='ff-el-input--content'><input type=\"email\" name=\"email\" id=\"ff_1_email\" class=\"ff-el-form-control\" placeholder=\"Email Address\" data-name=\"email\"  aria-invalid=\"false\" aria-required=true><\/div><\/div><div class='ff-el-group'><div class=\"ff-el-input--label asterisk-right\"><label for='ff_1_subject' id='label_ff_1_subject' aria-label=\"Subject\">Subject<\/label><\/div><div class='ff-el-input--content'><input type=\"text\" name=\"subject\" class=\"ff-el-form-control\" placeholder=\"Subject\" data-name=\"subject\" id=\"ff_1_subject\"  aria-invalid=\"false\" aria-required=false><\/div><\/div><div class='ff-el-group'><div class=\"ff-el-input--label ff-el-is-required asterisk-right\"><label for='ff_1_message' id='label_ff_1_message' aria-label=\"Your Message\">Your Message<\/label><\/div><div class='ff-el-input--content'><textarea aria-required=\"true\" aria-labelledby=\"label_ff_1_message\" name=\"message\" id=\"ff_1_message\" class=\"ff-el-form-control\" placeholder=\"Your Message\" rows=\"4\" cols=\"2\" data-name=\"message\" ><\/textarea><\/div><\/div><div class='ff-el-group ' style='margin-bottom: 0;'><div class='ff-el-input--content'><div data-fluent_id='1' name='cf-turnstile-response'><div\n\t\tdata-sitekey='0x4AAAAAAFR_A6IRFH-zWvr4'\n\t\tdata-theme='light'\n\t\tid='fluentform-turnstile-1-1'\n\t\tclass='ff-el-turnstile cf-turnstile'\n\t\tdata-appearance='interaction-only'><\/div><\/div><\/div><\/div><div class='ff-el-group ff-text-left ff_submit_btn_wrapper'><button type=\"submit\" class=\"ff-btn ff-btn-submit ff-btn-md ff_btn_style\"  aria-label=\"Submit Form\">Submit Form<\/button><\/div><\/fieldset><\/form><div id='fluentform_1_errors' class='ff-errors-in-stack ff_form_instance_1_1 ff-form-loading_errors ff_form_instance_1_1_errors'><\/div><\/div>            <script type=\"text\/javascript\">\n                window.fluent_form_ff_form_instance_1_1 = {\"id\":\"1\",\"ajaxUrl\":\"https:\\\/\\\/fgvhp.com\\\/wp-admin\\\/admin-ajax.php\",\"settings\":{\"layout\":{\"labelPlacement\":\"top\",\"helpMessagePlacement\":\"with_label\",\"errorMessagePlacement\":\"inline\",\"cssClassName\":\"\",\"asteriskPlacement\":\"asterisk-right\"},\"restrictions\":{\"denyEmptySubmission\":{\"enabled\":false}}},\"form_instance\":\"ff_form_instance_1_1\",\"form_id_selector\":\"fluentform_1\",\"rules\":{\"names[first_name]\":{\"required\":{\"value\":false,\"message\":\"This field is required\"}},\"names[middle_name]\":{\"required\":{\"value\":false,\"message\":\"This field is required\"}},\"names[last_name]\":{\"required\":{\"value\":false,\"message\":\"This field is required\"}},\"email\":{\"required\":{\"value\":true,\"message\":\"This field is required\"},\"email\":{\"value\":true,\"message\":\"This field must contain a valid email\"}},\"subject\":{\"required\":{\"value\":false,\"message\":\"This field is required\"}},\"message\":{\"required\":{\"value\":true,\"message\":\"This field is required\"}},\"cf-turnstile-response\":[]},\"debounce_time\":300,\"file_upload_settings\":[]};\n                            <\/script>\n            <\/div>\n<\/div><\/div><\/section>\n\n","protected":false},"excerpt":{"rendered":"<p>Home \/ Tools \/ Isolator leak rate calculator Isolators \u00b7 Calculator Isolator Leak Rate Calculator (ISO 10648-2) Turn a pressure [&hellip;]<\/p>\n","protected":false},"author":0,"featured_media":0,"parent":29,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-30","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/fgvhp.com\/ru\/wp-json\/wp\/v2\/pages\/30","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fgvhp.com\/ru\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/fgvhp.com\/ru\/wp-json\/wp\/v2\/types\/page"}],"replies":[{"embeddable":true,"href":"https:\/\/fgvhp.com\/ru\/wp-json\/wp\/v2\/comments?post=30"}],"version-history":[{"count":0,"href":"https:\/\/fgvhp.com\/ru\/wp-json\/wp\/v2\/pages\/30\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/fgvhp.com\/ru\/wp-json\/wp\/v2\/pages\/29"}],"wp:attachment":[{"href":"https:\/\/fgvhp.com\/ru\/wp-json\/wp\/v2\/media?parent=30"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}