{"id":20731,"date":"2026-11-03T10:08:53","date_gmt":"2026-11-03T02:08:53","guid":{"rendered":"https:\/\/www.wehopower.com\/news\/tx4l-celsius-fahrenheit-recipe-unit-change\/"},"modified":"2026-11-03T10:08:53","modified_gmt":"2026-11-03T02:08:53","slug":"tx4l-celsius-fahrenheit-recipe-unit-change","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/el\/news\/tx4l-celsius-fahrenheit-recipe-unit-change\/","title":{"rendered":"TX4-L Celsius and Fahrenheit: Audit the Whole Recipe Before a Unit Change"},"content":{"rendered":"<figure class=\"hero\"><a href=\"https:\/\/www.wehopower.com\/el\/product\/tx4-series-tx4-l-economic-dual-display-pid-temperature-controller\/\"><img decoding=\"async\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/hero-6.webp\" alt=\"TX4-L Celsius and Fahrenheit: Audit the Whole Recipe Before a Unit Change  title=\" fetchpriority=\"high\" tx4-l celsius and fahrenheit: audit the whole recipe before unit change title=\"\"><\/a><figcaption>A recipe review compares absolute temperatures and temperature intervals separately. Values on the external reference screen are hypothetical; the controller retains its original display artwork. AI-assisted illustration.<\/figcaption><a class=\"original-link\" href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/original-3.png\">View original product image<\/a><\/figure>\n<p><strong>A temperature-unit change requires a recipe audit, not only a new symbol on the TX4-L display.<\/strong> Review set value, limits, alarms, differential values and external records together. Absolute temperatures and temperature differences use different conversion formulas.<\/p>\n<p>This guide is for an OEM commissioning engineer transferring a temperature-control recipe between markets or operating instructions. It provides an arithmetic cross-check and a read-back method. It does not assume that a TX4-L automatically converts every parameter when the unit setting changes.<\/p>\n<nav class=\"toc\" aria-label=\"On this page\">\n<ol>\n<li><a href=\"#supported-setting\">Confirm the unit function and the complete configuration<\/a><\/li>\n<li><a href=\"#two-formulas\">Separate absolute values from differences<\/a><\/li>\n<li><a href=\"#worked-recipe\">A sample recipe with three kinds of values<\/a><\/li>\n<li><a href=\"#controlled-change\">Use a controlled old-to-new comparison<\/a><\/li>\n<li><a href=\"#verify-real-reference\">Check measurement and action with a traceable reference<\/a><\/li>\n<li><a href=\"#release-record\">Release the complete recipe, not a screenshot<\/a><\/li>\n<\/ol>\n<\/nav>\n<section id=\"supported-setting\">\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_86 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">\u03a0\u03af\u03bd\u03b1\u03ba\u03b1\u03c2 \u03c0\u03b5\u03c1\u03b9\u03b5\u03c7\u03bf\u03bc\u03ad\u03bd\u03c9\u03bd<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">\u039c\u03c0\u03b1\u03c1\u03ad\u03c4\u03b1<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.wehopower.com\/el\/news\/tx4l-celsius-fahrenheit-recipe-unit-change\/#Confirm_the_unit_function_and_the_complete_configuration\" >Confirm the unit function and the complete configuration<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.wehopower.com\/el\/news\/tx4l-celsius-fahrenheit-recipe-unit-change\/#Separate_absolute_values_from_differences\" >Separate absolute values from differences<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.wehopower.com\/el\/news\/tx4l-celsius-fahrenheit-recipe-unit-change\/#A_sample_recipe_with_three_kinds_of_values\" >A sample recipe with three kinds of values<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.wehopower.com\/el\/news\/tx4l-celsius-fahrenheit-recipe-unit-change\/#Use_a_controlled_old-to-new_comparison\" >Use a controlled old-to-new comparison<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.wehopower.com\/el\/news\/tx4l-celsius-fahrenheit-recipe-unit-change\/#Check_measurement_and_action_with_a_traceable_reference\" >Check measurement and action with a traceable reference<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.wehopower.com\/el\/news\/tx4l-celsius-fahrenheit-recipe-unit-change\/#Release_the_complete_recipe_not_a_screenshot\" >Release the complete recipe, not a screenshot<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.wehopower.com\/el\/news\/tx4l-celsius-fahrenheit-recipe-unit-change\/#Unit-change_recipe_audit\" >Unit-change recipe audit<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.wehopower.com\/el\/news\/tx4l-celsius-fahrenheit-recipe-unit-change\/#Sources_and_further_reading\" >Sources and further reading<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Confirm_the_unit_function_and_the_complete_configuration\"><\/span>Confirm the unit function and the complete configuration<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u039f <a href=\"https:\/\/www.wehopower.com\/el\/product\/tx4-series-tx4-l-economic-dual-display-pid-temperature-controller\/\">WEHO TX4-L page<\/a> describes\u00b0C\/\u00b0F selection and the front unit indication. The <a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2023\/11\/TX4.pdf\">TX4 230808EN manual<\/a> includes temperature-unit and decimal-point settings, set-value limits and alarm parameters. These entries make a complete configuration record necessary; the front symbol alone cannot prove that every stored value has the intended meaning.<\/p>\n<p>Read the applicable manual and record the full ordering code and firmware information available on the unit. Do not infer the conversion behavior of all parameters from the presence of a\u00b0C\/\u00b0F menu. If automatic handling is not explicit, verify the values under an approved setup procedure before enabling the process output.<\/p>\n<\/section>\n<section id=\"two-formulas\">\n<h2><span class=\"ez-toc-section\" id=\"Separate_absolute_values_from_differences\"><\/span>Separate absolute values from differences<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>For an absolute temperature, use <strong>\u00b0F =\u00b0C \u00d79\/5 +32<\/strong>. For a difference or interval, use <strong>\u0394\u00b0F =\u0394\u00b0C \u00d79\/5<\/strong>, with no added 32. A ten-degree Celsius differential is an eighteen-degree Fahrenheit interval, not fifty degrees Fahrenheit.<\/p>\n<p>The parameter&#8217;s actual meaning determines which formula applies. An absolute high-temperature alarm, an alarm relative to the set value and an ON\/OFF return interval are different objects. Review the selected alarm type and its parameter description before converting a number labeled simply \u201calarm.\u201d A parameter name copied from a spreadsheet is not enough.<\/p>\n<\/section>\n<section id=\"worked-recipe\">\n<h2><span class=\"ez-toc-section\" id=\"A_sample_recipe_with_three_kinds_of_values\"><\/span>A sample recipe with three kinds of values<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure id=\"fig-diagram\" class=\"diagram\"><img decoding=\"async\" class=\"technical-desktop\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/diagram-6.svg\" alt=\"TX4-L Celsius and Fahrenheit: Audit the Whole Recipe Before a Unit Change  title=\" loading=\"lazy\" tx4-l celsius and fahrenheit: audit the whole recipe before unit change title=\"\"><img decoding=\"async\" class=\"technical-mobile\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/diagram-mobile-6.svg\" alt=\"TX4-L Celsius and Fahrenheit: Audit the Whole Recipe Before a Unit Change  title=\" loading=\"lazy\" tx4-l celsius and fahrenheit: audit the whole recipe before unit change title=\"\"><figcaption>Hypothetical unit conversion;not a verified controller conversion sequence.<\/figcaption><a class=\"original-link\" href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/diagram-6.svg\">Open full-size technical illustration<\/a><\/figure>\n<div class=\"table-scroll\">\n<table>\n<thead>\n<tr>\n<th scope=\"col\">Hypothetical item<\/th>\n<th scope=\"col\">Celsius record<\/th>\n<th scope=\"col\">Fahrenheit cross-check<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Set value, absolute<\/td>\n<td>180 \u00b0C<\/td>\n<td>356 \u00b0F<\/td>\n<\/tr>\n<tr>\n<td>Absolute high alarm<\/td>\n<td>200 \u00b0C<\/td>\n<td>392 \u00b0F<\/td>\n<\/tr>\n<tr>\n<td>Deviation above set value<\/td>\n<td>+10 \u00b0C<\/td>\n<td>+18 \u00b0F<\/td>\n<\/tr>\n<tr>\n<td>Return differential<\/td>\n<td>5 \u00b0C interval<\/td>\n<td>9 \u00b0F interval<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>The arithmetic is 180 \u00d71.8 +32=356;200 \u00d71.8 +32=392;10 \u00d71.8=18;5 \u00d71.8=9. These are illustrative recipe numbers, not recommended process values. A deviation alarm using+18 \u00b0F above 356 \u00b0F would correspond to 374 \u00b0F if that is how the documented alarm mode operates. It must not be confused with an absolute 18 \u00b0F threshold.<\/p>\n<\/section>\n<section id=\"controlled-change\">\n<h2><span class=\"ez-toc-section\" id=\"Use_a_controlled_old-to-new_comparison\"><\/span>Use a controlled old-to-new comparison<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Before changing units, capture the complete configuration with units attached to each numeric entry. Include input type, decimal resolution, set-value limits, alarm modes and the output-control settings that affect operation. Keep process power in the appropriate commissioning state so unexpected settings cannot energize equipment during comparison.<\/p>\n<p>After the unit change, read each relevant parameter back from the controller. Record whether the unit converted it, retained the same number, reset it or prevented the setting. Do not fill a spreadsheet with expected converted values and call them actual read-back. Any unsupported parameter behavior requires clarification from the applicable documentation or supplier.<\/p>\n<\/section>\n<section id=\"verify-real-reference\">\n<h2><span class=\"ez-toc-section\" id=\"Check_measurement_and_action_with_a_traceable_reference\"><\/span>Check measurement and action with a traceable reference<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Use a suitable reference or documented simulator for the selected input to check that the displayed temperature corresponds to the intended unit. Then verify the relevant control and alarm behavior under an approved procedure. Match external labels, HMI recipes, logs and operating instructions so one interface does not continue to interpret the old unit.<\/p>\n<p>Resolution also matters. A controller or recipe system that rounds whole degrees can represent a different interval after conversion. State the project&#8217;s acceptable representation and compare the stored\/read-back values with that requirement. Do not turn rounding into an undocumented process tolerance or claim a tighter measurement accuracy from an extra decimal place.<\/p>\n<\/section>\n<section id=\"release-record\">\n<h2><span class=\"ez-toc-section\" id=\"Release_the_complete_recipe_not_a_screenshot\"><\/span>Release the complete recipe, not a screenshot<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure id=\"fig-original\" class=\"product-original\"><a href=\"https:\/\/www.wehopower.com\/el\/product\/tx4-series-tx4-l-economic-dual-display-pid-temperature-controller\/\"><img decoding=\"async\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/original-3.png\" alt=\"TX4-L Celsius and Fahrenheit: Audit the Whole Recipe Before a Unit Change  title=\" loading=\"lazy\" tx4-l celsius and fahrenheit: audit the whole recipe before unit change title=\"\"><\/a><figcaption>Official TX4-L front-form illustration. The complete order code and rear connection option must be confirmed separately.<\/figcaption><a class=\"original-link\" href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/original-3.png\">View original image<\/a><\/figure>\n<p>The official TX4-L image shows the 96 \u00d796 mm front form and unit-indicator positions. Its photographed display is an identity illustration, not evidence that the worked recipe was loaded or tested. A release record should contain the old and new units, parameter read-back, arithmetic check, actual verification and the matching external documentation revision.<\/p>\n<p>After a controller replacement or recipe import, repeat the affected checks. A familiar set-value number can represent a very different process temperature when the unit setting changes, so both the number and its meaning must remain controlled.<\/p>\n<\/section>\n<section class=\"cta\">\n<p>Send <a href=\"https:\/\/www.wehopower.com\/el\/contact\/\">WEHO<\/a> the full TX4-L code, current and desired unit, input type, complete parameter record and any unexpected read-back. Ask for model-specific conversion behavior before approving the unit-change procedure.<\/p>\n<\/section>\n<section id=\"worksheet\" class=\"sheet\">\n<h2><span class=\"ez-toc-section\" id=\"Unit-change_recipe_audit\"><\/span>Unit-change recipe audit<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"sheet-row\"><label>Full model\/revision<input aria-label=\"Full model\/revision\"><\/label><label>Old\/new unit<input aria-label=\"Old\/new unit\"><\/label><label>Input type<input aria-label=\"Input type\"><\/label><label>External recipe revision<input aria-label=\"External recipe revision\"><\/label><label>Output commissioning state<input aria-label=\"Output commissioning state\"><\/label><\/div>\n<div class=\"table-scroll\">\n<table>\n<thead>\n<tr>\n<th scope=\"col\">Parameter<\/th>\n<th scope=\"col\">Absolute or interval<\/th>\n<th scope=\"col\">Old value\/unit<\/th>\n<th scope=\"col\">Calculated equivalent<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">Actual handling<\/td>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">Converted\/retained\/reset<\/td>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">Controller read-back<\/td>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">\u0394\u03b9\u03b1\u03c6\u03bf\u03c1\u03ac<\/td>\n<\/tr>\n<tr>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">Behavior verification<\/td>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">Reference\/input<\/td>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">Control\/alarm response<\/td>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">Evidence<\/td>\n<\/tr>\n<tr>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">External records<\/td>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">HMI\/labels\/logs<\/td>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">Updated revision<\/td>\n<td contenteditable=\"true\" aria-label=\"Worksheet cell\">Release<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>Blank project worksheet. Enter verified project data; example calculations above are not measurements.<\/p>\n<\/section>\n<section class=\"source-list\">\n<h2><span class=\"ez-toc-section\" id=\"Sources_and_further_reading\"><\/span>Sources and further reading<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ol>\n<li><a href=\"https:\/\/www.wehopower.com\/el\/product\/tx4-series-tx4-l-economic-dual-display-pid-temperature-controller\/\">WEHO TX4-L product information<\/a><\/li>\n<li><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2023\/11\/TX4.pdf\">TX4 230808EN parameter manual<\/a><\/li>\n<\/ol>\n<\/section>","protected":false},"excerpt":{"rendered":"<p>Convert a TX4-L recipe between Celsius and Fahrenheit with separate rules for absolute temperatures and differences. Verify every unit-dependent setting.<\/p>","protected":false},"author":2,"featured_media":20710,"parent":0,"menu_order":37,"comment_status":"","ping_status":"","template":"","format":"standard","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"news_category":[284],"class_list":["post-20731","news","type-news","status-publish","format-standard","has-post-thumbnail","hentry","news_category-product-articles","entry"],"acf":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/news\/20731","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/types\/news"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/comments?post=20731"}],"version-history":[{"count":0,"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/news\/20731\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/media\/20710"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/media?parent=20731"}],"wp:term":[{"taxonomy":"news_category","embeddable":true,"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/news_category?post=20731"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}