{"id":2614,"date":"2026-01-13T07:35:36","date_gmt":"2026-01-13T07:35:36","guid":{"rendered":"https:\/\/lightingrecipe.com\/?page_id=2614"},"modified":"2026-01-21T07:12:41","modified_gmt":"2026-01-21T07:12:41","slug":"flicker-pstlm-and-svm","status":"publish","type":"page","link":"https:\/\/lightingrecipe.com\/zh\/flicker-pstlm-and-svm\/","title":{"rendered":"\u983b\u9583\u3001PstLM \u8207 SVM"},"content":{"rendered":"<div class=\"wp-block-columns alignwide has-primary-color has-text-color has-link-color has-small-font-size wp-elements-3b80bc089a85cd8d77ca2dad494b12e5 is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-c788c38f6f9273de8ec34cf2c272aad1\"><strong><em>\u4ec0\u9ebc\u662f\u983b\u9583\uff08Flicker\uff09\uff1f<\/em><\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-e667b20551f3c7a53cf642f6bf72b966\" style=\"font-size:15px\">\u983b\u9583\u662f\u6307\u4eae\u5ea6\u96a8\u6642\u9593\u7522\u751f\u8b8a\u5316\u2014\u2014\u5149\u5f37\u6216\u4eae\u5ea6\u5feb\u901f\u8d77\u4f0f\uff0c\u4f7f\u5149\u7dda\u770b\u8d77\u4f86\u51fa\u73fe\u6ce2\u52d5\u6216\u8108\u52d5\u3002<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-c1e782b1830d9b24196ff537fc990326\"><strong><em>\u983b\u9583\u983b\u7387<\/em><\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-073b760e14b322d34bbca39eedb952e8\" style=\"font-size:15px\">\u4eba\u985e\u5c0d\u983b\u9583\u7684\u53cd\u61c9\u53d6\u6c7a\u65bc\u5176\u983b\u7387\uff0c\u983b\u7387\u4ee5\u8d6b\u8332\uff08Hz\uff09\u70ba\u55ae\u4f4d\uff0c\u8868\u793a\u5149\u6e90\u6bcf\u79d2\u958b\u95dc\u6216\u4eae\u5ea6\u8b8a\u5316\u7684\u6b21\u6578\u30021 Hz \u7b49\u65bc\u6bcf\u79d2\u4e00\u6b21\u5faa\u74b0\u6216\u4e00\u6b21\u983b\u9583\u3002\u96a8\u8457\u983b\u7387\u63d0\u9ad8\uff0c\u4eae\u5ea6\u5728\u6700\u5c0f\u503c\u8207\u6700\u5927\u503c\u4e4b\u9593\u7684\u8b8a\u5316\u5c0d\u4eba\u773c\u800c\u8a00\u6703\u8b8a\u5f97\u8d8a\u4f86\u8d8a\u4e0d\u660e\u986f\u3002<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-6a75b2c69e870a5f19ab158fb71f87ca\" style=\"font-size:15px\">\ud83d\udd39 3\u201370 Hz\uff1a\u983b\u9583\u6e05\u695a\u53ef\u898b<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-b06a89039bc63b97c518d355c5d2b9eb\" style=\"font-size:15px\">\ud83d\udd39 \u6700\u9ad8\u7d04 100 Hz\uff1a\u591a\u6578\u4eba\u4ecd\u53ef\u5bdf\u89ba\u983b\u9583\uff0c\u8996\u5149\u7167\u689d\u4ef6\u800c\u5b9a<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-aa63b0e1102810028b567781e678a354\" style=\"font-size:15px\">\ud83d\udd39 100\u2013200 Hz\uff1a\u983b\u9583\u8f03\u4e0d\u660e\u986f\uff0c\u4f46\u53ef\u80fd\u5728\u6f5b\u610f\u8b58\u4e2d\u88ab\u5bdf\u89ba<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-aa1f771965940c77941dc9e9b14a8c47\" style=\"font-size:15px\">\ud83d\udd39 \u9ad8\u65bc 200 Hz\uff1a\u4eba\u773c\u7121\u6cd5\u611f\u77e5\u983b\u9583<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-61e86a58bf09354602fdf196d2d28532\" style=\"font-size:15px\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-00d6a1a8f3df49cadaeb709dca1189ac\"><strong><em>\u5982\u4f55\u91cf\u6e2c\u983b\u9583\uff1f<\/em><\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-1b9edb25002950884fac1a033f573246\" style=\"font-size:15px\">\u91cf\u6e2c\u983b\u9583\u7684\u5169\u7a2e\u5e38\u898b\u65b9\u5f0f\u70ba\u983b\u9583\u767e\u5206\u6bd4\uff08\u8abf\u8b8a\u7387 %\uff09\u8207\u983b\u9583\u6307\u6578\uff08Flicker Index\uff09\u3002<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-61e86a58bf09354602fdf196d2d28532\" style=\"font-size:15px\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-ba0b7ac7153715dc70b21b7b769a439f\"><strong><em>\u983b\u9583\u767e\u5206\u6bd4<\/em><\/strong><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"494\" src=\"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/09\/unnamed-2.png\" alt=\"\" class=\"wp-image-1575\" style=\"width:792px;height:auto\" srcset=\"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/09\/unnamed-2.png 1024w, https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/09\/unnamed-2-300x145.png 300w, https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/09\/unnamed-2-768x371.png 768w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-4e61e623f95967133d584c0f2557e348\" style=\"font-size:15px\">\u983b\u9583\u767e\u5206\u6bd4\u7528\u65bc\u8861\u91cf\u53ef\u611f\u77e5\u983b\u9583\u7684\u5e45\u5ea6\u3002\u5176\u8a08\u7b97\u65b9\u5f0f\u70ba\uff1a\u5728\u55ae\u4e00\u9031\u671f\u5167\uff0c\u5c07\u6700\u5927\u5149\u8f38\u51fa\u8207\u6700\u5c0f\u5149\u8f38\u51fa\u7684\u5dee\u503c\uff0c\u9664\u4ee5\u5169\u8005\u7684\u7e3d\u548c\uff0c\u4e26\u4ee5\u767e\u5206\u6bd4\u8868\u793a\u3002<br><em><br>\u516c\u5f0f\uff1a<\/em><br><strong>\u983b\u9583\u767e\u5206\u6bd4\uff08Flicker %\uff09\uff1d 100 \u00d7\uff08A \u2212 B\uff09\uff0f\uff08A + B\uff09<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-afb58833155162a485c22337717d4486\" style=\"font-size:15px\">A = \u6700\u5927\u503c<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-00f9c915bf8cb75362627c5bc6273cac\" style=\"font-size:15px\">B = \u6700\u5c0f\u503c<br>0%\uff1d\u7121\u983b\u9583\uff1b100%\uff1d\u6700\u9ad8\u983b\u9583<br><br>IEEE 1789 \u662f\u76ee\u524d\u6700\u5ee3\u6cdb\u4f7f\u7528\u3001\u7528\u65bc\u898f\u7bc4 LED \u983b\u9583\u7684\u6a19\u6e96\u3002<br><br><strong>\u5efa\u8b70\u5be6\u52d9 1\uff08RP1\uff09<\/strong>:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-9d43a0d388729f40ec1d1a35f5f2cd78\" style=\"font-size:15px\">\ud83d\udd39 \u4f4e\u65bc 90 Hz\uff1a\u8abf\u8b8a\u7387\uff08%\uff09 &lt; 0.025 \u00d7 \u983b\u7387<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-6c6dc33e7344c327e452a4b5606e6b78\" style=\"font-size:15px\">\ud83d\udd39 90 \u81f3 1,250 Hz\uff1a\u8abf\u8b8a\u7387\uff08%\uff09 &lt; 0.08 \u00d7 \u983b\u7387<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-f9bc4534f9379113e377401d311a0d72\" style=\"font-size:15px\">\ud83d\udd39 \u9ad8\u65bc 1,250 Hz\uff1a\u8abf\u8b8a\u7387\uff08%\uff09\u4e0d\u53d7\u9650\u5236<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-14f235c376f87070780f395649801237\" style=\"font-size:15px\"><strong>\u5efa\u8b70\u5be6\u52d9 2\uff08RP2\uff0d\u9069\u7528\u65bc NOEL\uff09<\/strong>:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-8977b2a2311f9037369a3ade7fecdff4\" style=\"font-size:15px\">\ud83d\udd39 \u4f4e\u65bc 90 Hz\uff1a\u8abf\u8b8a\u7387\uff08%\uff09 &lt; 0.01 \u00d7 \u983b\u7387<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-c38476c46be005eb159a2df307b891af\" style=\"font-size:15px\">\ud83d\udd39 90 \u81f3 3,000 Hz\uff1a\u8abf\u8b8a\u7387\uff08%\uff09 &lt; 0.0333 \u00d7 \u983b\u7387<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-32dee19e68bb0826355520c987d219fa\" style=\"font-size:15px\">\ud83d\udd39 \u9ad8\u65bc 3,000 Hz\uff1a\u8abf\u8b8a\u7387\uff08%\uff09\u4e0d\u53d7\u9650\u5236<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-61e86a58bf09354602fdf196d2d28532\" style=\"font-size:15px\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-02ec812d3e72868ce1c3ba96c940e032\" style=\"font-size:15px\">\u591a\u6578 LED \u71c8\u5177\u7684\u983b\u9583\u983b\u7387\u70ba\u5e02\u96fb\u983b\u7387\u7684\u5169\u500d\uff08\u6b50\u6d32\u70ba 50 Hz\uff0c\u7f8e\u570b\u8207\u52a0\u62ff\u5927\u70ba 60 Hz\uff09\uff0c\u56e0\u6b64\u6703\u7522\u751f\u4ee5\u4e0b\u5178\u578b\u7684\u983b\u9583\u6578\u503c\uff1a<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-76e629a7f6e2b7d713f2b2b37d3feba7\" style=\"font-size:15px\"><strong>50 Hz \u5e02\u96fb\uff08100 Hz \u983b\u9583\uff09<\/strong>:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-4df88a6ff5333adbf7da8b2713f41ce3\" style=\"font-size:15px\">\ud83d\udd39 RP1\uff08\u826f\u597d\uff09\uff1a\u6700\u5927\u8abf\u8b8a\u7387 = 8.0%<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-c491d30e8971347bc597be55f34debd8\" style=\"font-size:15px\">\ud83d\udd39 RP2\uff08\u6700\u4f73\uff09\uff1a\u6700\u5927\u8abf\u8b8a\u7387 = 3.3%<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-92a064280800e939d9f1614090841561\" style=\"font-size:15px\"><strong>60 Hz \u5e02\u96fb\uff08120 Hz \u983b\u9583\uff09<\/strong>:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-e72d8881510baf335148812e984506d7\" style=\"font-size:15px\">\ud83d\udd39 RP1\uff08\u826f\u597d\uff09\uff1a\u6700\u5927\u8abf\u8b8a\u7387 = 9.6%<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-806382b70d8196e309ee5bc747f34dff\" style=\"font-size:15px\">\ud83d\udd39 RP2\uff08\u6700\u4f73\uff09\uff1a\u6700\u5927\u8abf\u8b8a\u7387 = 4.0%<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-61e86a58bf09354602fdf196d2d28532\" style=\"font-size:15px\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-d254972b30a58ce92b600edc1740665b\"><strong><em>\u983b\u9583\u6307\u6578<\/em><\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-0dc920bc1a8a15214577795731c780c5\" style=\"font-size:15px\">\u983b\u9583\u6307\u6578\u7684\u8a08\u7b97\u65b9\u5f0f\u70ba\uff1a\u5148\u6c42\u51fa\u4e00\u500b\u9031\u671f\u5167\u7684\u5e73\u5747\u5149\u8f38\u51fa\u503c\uff0c\u518d\u91cf\u6e2c\u5149\u8f38\u51fa\u66f2\u7dda\u4e2d\u9ad8\u65bc\u8207\u4f4e\u65bc\u8a72\u5e73\u5747\u503c\u7684\u9762\u7a4d\u3002\u983b\u9583\u6307\u6578\u5373\u70ba\u5e73\u5747\u503c\u4ee5\u4e0a\u9762\u7a4d\u5360\u7e3d\u9762\u7a4d\u7684\u6bd4\u4f8b\u3002<br><br><em>\u516c\u5f0f\uff1a<\/em><br><strong>\u983b\u9583\u6307\u6578\uff08Flicker Index\uff09\uff1d \u5e73\u5747\u503c\u4ee5\u4e0a\u9762\u7a4d \uff0f\uff08\u5e73\u5747\u503c\u4ee5\u4e0a\u9762\u7a4d + \u5e73\u5747\u503c\u4ee5\u4e0b\u9762\u7a4d\uff09<\/strong><br>\u6578\u503c\u7bc4\u570d\u70ba 0 \u81f3 1\uff1b\u6578\u503c\u8d8a\u4f4e\uff0c\u983b\u9583\u8d8a\u4e0d\u660e\u986f\u3002<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-5542e257e2886fd51f653c05088e6e06\"><br><strong><em>\u4ec0\u9ebc\u662f PstLM \u8207 SVM\uff1f<\/em><\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-7ec13252f8341295796f65ff28472af3\" style=\"font-size:15px\"><strong><em>PstLM\uff08\u77ed\u671f\u5149\u8abf\u8b8a\uff09<\/em><\/strong><br><br>\u9069\u7528\u65bc 0\u201380 Hz \u7bc4\u570d\u5167\u7684\u983b\u9583\u3002\u6578\u503c\u70ba 1.0 \u8868\u793a\u4e00\u822c\u89c0\u5bdf\u8005\u6709 50% \u7684\u6a5f\u7387\u53ef\u5bdf\u89ba\u983b\u9583\u30020 \u70ba\u7406\u60f3\u503c\uff1b\u2264 1.0 \u7684\u6578\u503c\u7686\u5c6c\u53ef\u63a5\u53d7\u7bc4\u570d\u3002<br><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-7d8b99e5df55ea71ce931972510cce65\" style=\"font-size:15px\"><strong><strong><em> <\/em><\/strong><em>SVM\uff08\u983b\u9583\u53ef\u898b\u5ea6\u6307\u6a19\uff09<\/em><\/strong><br><br>\u6db5\u84cb 80\u20132,000 Hz \u7684\u983b\u7387\u7bc4\u570d\u3002SVM = 1.0 \u70ba\u4e00\u822c\u89c0\u5bdf\u8005\u53ef\u5bdf\u89ba\u983b\u9583\u7684\u81e8\u754c\u503c\u3002<br><br>\ud83d\udd39 \u7576 LED \u71c8\u5177\u7b26\u5408\u4ee5\u4e0b\u689d\u4ef6\u6642\uff0c\u53ef\u8996\u70ba\u7121\u983b\u9583\uff1aSVM \u2264 0.4\uff0c\u4e14 PstLM \u2264 1.0<\/p>\n<\/div>\n<\/div>\n\n\n\n<figure class=\"wp-block-video alignwide\"><video height=\"1080\" style=\"aspect-ratio: 1920 \/ 1080;\" width=\"1920\" controls src=\"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/08\/Lighting-Fundamentals-Part-4.mp4\"><\/video><\/figure>\n\n\n\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>What is Flicker? Flicker refers to variations in luminance over time\u2014rapid changes in light intensity or brightness, making the light appear to fluctuate or pulse. Flicker Frequency Human response to flicker depends on frequency, measured in Hertz (Hz), indicating how often a light source switches on and off or varies in intensity per second. One Hz equals one cycle or flicker per second. As the frequency increases, changes in brightness between minimum and maximum levels become less noticeable to the eye. \ud83d\udd393\u201370 Hz: Flicker is clearly visible. \ud83d\udd39Up to ~100 Hz: Flicker is noticeable to most, depending on light conditions. \ud83d\udd39100\u2013200 Hz: Flicker is less noticeable but may be subconsciously detected. \ud83d\udd39Above 200 Hz: Flicker is not perceptible to the human eye. How to Measure Flicker? Two common ways to measure flicker are percent flicker (modulation %) and flicker index. Percent Flicker Percent flicker measures the magnitude of perceived flicker. It is calculated by taking the difference between the maximum and minimum light output during a single cycle, dividing it by their sum, and expressing the result as a percentage.Formula:Flicker % = 100 \u00d7 (A &#8211; B) \/ (A + B) A= Maximum Value B= Minimum Value0% = no flicker; 100% = highest flicker. IEEE 1789 is the most widely used standard for regulating flicker in LEDs. Recommended Practice 1 (RP1): \ud83d\udd39Below 90 Hz: Modulation (%) &lt; 0.025 \u00d7 frequency \ud83d\udd3990 to 1,250 Hz: Modulation (%) &lt; 0.08 \u00d7 frequency \ud83d\udd39Above 1,250 Hz: No restriction on modulation (%) Recommended Practice 2 (RP2 \u2013 for NOEL): \ud83d\udd39Below 90 Hz: Modulation (%) &lt; 0.01 \u00d7 frequency \ud83d\udd3990 to 3,000 Hz: Modulation (%) &lt; 0.0333 \u00d7 frequency \ud83d\udd39Above 3,000 Hz: No restriction on modulation (%) Most LED fixtures flicker at twice the mains frequency (50 Hz in Europe, 60 Hz in the USA and Canada), leading to these typical flicker values: 50 Hz mains (100 Hz flicker): \ud83d\udd39RP1 (Good): Max modulation = 8.0% \ud83d\udd39RP2 (Best): Max modulation = 3.3% 60 Hz mains (120 Hz flicker): \ud83d\udd39RP1 (Good): Max modulation = 9.6% \ud83d\udd39RP2 (Best): Max modulation = 4.0% Flicker Index Flicker index is calculated by determining the average light output during a cycle, then measuring the area above and below this average. The index is the ratio of the area above the average to the total area. Formula:Flicker Index = Area above average \/ (Area above + Area below)Ranges from 0 to 1; lower values = less visible flicker. What is PstLM and SVM? PstLM (Short-Term Light Modulation) Applies to flicker in the 0\u201380 Hz range. A value of 1.0 means a 50% chance that an average observer will perceive flicker. A value of 0 is ideal; values \u22641.0 are acceptable. SVM (Stroboscopic Visibility Measure) Covers the 80\u20132,000 Hz range. An SVM of 1.0 is the visibility threshold for an average observer. \ud83d\udd39An LED luminaire is considered flicker-free if: SVM \u2264 0.4 and PstLM \u2264 1.0<\/p>","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_glsr_average":0,"_glsr_ranking":0,"_glsr_reviews":0,"footnotes":""},"class_list":["post-2614","page","type-page","status-publish","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.0 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Flicker, PstLM, and SVM -<\/title>\n<meta name=\"robots\" content=\"noindex, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<meta property=\"og:locale\" content=\"zh_TW\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Flicker, PstLM, and SVM -\" \/>\n<meta property=\"og:description\" content=\"What is Flicker? Flicker refers to variations in luminance over time\u2014rapid changes in light intensity or brightness, making the light appear to fluctuate or pulse. Flicker Frequency Human response to flicker depends on frequency, measured in Hertz (Hz), indicating how often a light source switches on and off or varies in intensity per second. One Hz equals one cycle or flicker per second. As the frequency increases, changes in brightness between minimum and maximum levels become less noticeable to the eye. \ud83d\udd393\u201370 Hz: Flicker is clearly visible. \ud83d\udd39Up to ~100 Hz: Flicker is noticeable to most, depending on light conditions. \ud83d\udd39100\u2013200 Hz: Flicker is less noticeable but may be subconsciously detected. \ud83d\udd39Above 200 Hz: Flicker is not perceptible to the human eye. How to Measure Flicker? Two common ways to measure flicker are percent flicker (modulation %) and flicker index. Percent Flicker Percent flicker measures the magnitude of perceived flicker. It is calculated by taking the difference between the maximum and minimum light output during a single cycle, dividing it by their sum, and expressing the result as a percentage.Formula:Flicker % = 100 \u00d7 (A &#8211; B) \/ (A + B) A= Maximum Value B= Minimum Value0% = no flicker; 100% = highest flicker. IEEE 1789 is the most widely used standard for regulating flicker in LEDs. Recommended Practice 1 (RP1): \ud83d\udd39Below 90 Hz: Modulation (%) &lt; 0.025 \u00d7 frequency \ud83d\udd3990 to 1,250 Hz: Modulation (%) &lt; 0.08 \u00d7 frequency \ud83d\udd39Above 1,250 Hz: No restriction on modulation (%) Recommended Practice 2 (RP2 \u2013 for NOEL): \ud83d\udd39Below 90 Hz: Modulation (%) &lt; 0.01 \u00d7 frequency \ud83d\udd3990 to 3,000 Hz: Modulation (%) &lt; 0.0333 \u00d7 frequency \ud83d\udd39Above 3,000 Hz: No restriction on modulation (%) Most LED fixtures flicker at twice the mains frequency (50 Hz in Europe, 60 Hz in the USA and Canada), leading to these typical flicker values: 50 Hz mains (100 Hz flicker): \ud83d\udd39RP1 (Good): Max modulation = 8.0% \ud83d\udd39RP2 (Best): Max modulation = 3.3% 60 Hz mains (120 Hz flicker): \ud83d\udd39RP1 (Good): Max modulation = 9.6% \ud83d\udd39RP2 (Best): Max modulation = 4.0% Flicker Index Flicker index is calculated by determining the average light output during a cycle, then measuring the area above and below this average. The index is the ratio of the area above the average to the total area. Formula:Flicker Index = Area above average \/ (Area above + Area below)Ranges from 0 to 1; lower values = less visible flicker. What is PstLM and SVM? PstLM (Short-Term Light Modulation) Applies to flicker in the 0\u201380 Hz range. A value of 1.0 means a 50% chance that an average observer will perceive flicker. A value of 0 is ideal; values \u22641.0 are acceptable. SVM (Stroboscopic Visibility Measure) Covers the 80\u20132,000 Hz range. An SVM of 1.0 is the visibility threshold for an average observer. \ud83d\udd39An LED luminaire is considered flicker-free if: SVM \u2264 0.4 and PstLM \u2264 1.0\" \/>\n<meta property=\"og:url\" content=\"https:\/\/lightingrecipe.com\/zh\/flicker-pstlm-and-svm\/\" \/>\n<meta property=\"article:modified_time\" content=\"2026-01-21T07:12:41+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/09\/unnamed-2.png\" \/>\n\t<meta property=\"og:image:width\" content=\"1024\" \/>\n\t<meta property=\"og:image:height\" content=\"494\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u9810\u4f30\u95b1\u8b80\u6642\u9593\" \/>\n\t<meta name=\"twitter:data1\" content=\"3 \u5206\u9418\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/flicker-pstlm-and-svm\\\/\",\"url\":\"https:\\\/\\\/lightingrecipe.com\\\/flicker-pstlm-and-svm\\\/\",\"name\":\"Flicker, PstLM, and SVM -\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/flicker-pstlm-and-svm\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/flicker-pstlm-and-svm\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/lightingrecipe.com\\\/wp-content\\\/uploads\\\/2025\\\/09\\\/unnamed-2.png\",\"datePublished\":\"2026-01-13T07:35:36+00:00\",\"dateModified\":\"2026-01-21T07:12:41+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/flicker-pstlm-and-svm\\\/#breadcrumb\"},\"inLanguage\":\"zh-TW\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/lightingrecipe.com\\\/flicker-pstlm-and-svm\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"zh-TW\",\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/flicker-pstlm-and-svm\\\/#primaryimage\",\"url\":\"https:\\\/\\\/lightingrecipe.com\\\/wp-content\\\/uploads\\\/2025\\\/09\\\/unnamed-2.png\",\"contentUrl\":\"https:\\\/\\\/lightingrecipe.com\\\/wp-content\\\/uploads\\\/2025\\\/09\\\/unnamed-2.png\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/flicker-pstlm-and-svm\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/lightingrecipe.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Flicker, PstLM, and SVM\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/#website\",\"url\":\"https:\\\/\\\/lightingrecipe.com\\\/\",\"name\":\"\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/lightingrecipe.com\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"zh-TW\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Flicker, PstLM, and SVM -","robots":{"index":"noindex","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"og_locale":"zh_TW","og_type":"article","og_title":"Flicker, PstLM, and SVM -","og_description":"What is Flicker? Flicker refers to variations in luminance over time\u2014rapid changes in light intensity or brightness, making the light appear to fluctuate or pulse. Flicker Frequency Human response to flicker depends on frequency, measured in Hertz (Hz), indicating how often a light source switches on and off or varies in intensity per second. One Hz equals one cycle or flicker per second. As the frequency increases, changes in brightness between minimum and maximum levels become less noticeable to the eye. \ud83d\udd393\u201370 Hz: Flicker is clearly visible. \ud83d\udd39Up to ~100 Hz: Flicker is noticeable to most, depending on light conditions. \ud83d\udd39100\u2013200 Hz: Flicker is less noticeable but may be subconsciously detected. \ud83d\udd39Above 200 Hz: Flicker is not perceptible to the human eye. How to Measure Flicker? Two common ways to measure flicker are percent flicker (modulation %) and flicker index. Percent Flicker Percent flicker measures the magnitude of perceived flicker. It is calculated by taking the difference between the maximum and minimum light output during a single cycle, dividing it by their sum, and expressing the result as a percentage.Formula:Flicker % = 100 \u00d7 (A &#8211; B) \/ (A + B) A= Maximum Value B= Minimum Value0% = no flicker; 100% = highest flicker. IEEE 1789 is the most widely used standard for regulating flicker in LEDs. Recommended Practice 1 (RP1): \ud83d\udd39Below 90 Hz: Modulation (%) &lt; 0.025 \u00d7 frequency \ud83d\udd3990 to 1,250 Hz: Modulation (%) &lt; 0.08 \u00d7 frequency \ud83d\udd39Above 1,250 Hz: No restriction on modulation (%) Recommended Practice 2 (RP2 \u2013 for NOEL): \ud83d\udd39Below 90 Hz: Modulation (%) &lt; 0.01 \u00d7 frequency \ud83d\udd3990 to 3,000 Hz: Modulation (%) &lt; 0.0333 \u00d7 frequency \ud83d\udd39Above 3,000 Hz: No restriction on modulation (%) Most LED fixtures flicker at twice the mains frequency (50 Hz in Europe, 60 Hz in the USA and Canada), leading to these typical flicker values: 50 Hz mains (100 Hz flicker): \ud83d\udd39RP1 (Good): Max modulation = 8.0% \ud83d\udd39RP2 (Best): Max modulation = 3.3% 60 Hz mains (120 Hz flicker): \ud83d\udd39RP1 (Good): Max modulation = 9.6% \ud83d\udd39RP2 (Best): Max modulation = 4.0% Flicker Index Flicker index is calculated by determining the average light output during a cycle, then measuring the area above and below this average. The index is the ratio of the area above the average to the total area. Formula:Flicker Index = Area above average \/ (Area above + Area below)Ranges from 0 to 1; lower values = less visible flicker. What is PstLM and SVM? PstLM (Short-Term Light Modulation) Applies to flicker in the 0\u201380 Hz range. A value of 1.0 means a 50% chance that an average observer will perceive flicker. A value of 0 is ideal; values \u22641.0 are acceptable. SVM (Stroboscopic Visibility Measure) Covers the 80\u20132,000 Hz range. An SVM of 1.0 is the visibility threshold for an average observer. \ud83d\udd39An LED luminaire is considered flicker-free if: SVM \u2264 0.4 and PstLM \u2264 1.0","og_url":"https:\/\/lightingrecipe.com\/zh\/flicker-pstlm-and-svm\/","article_modified_time":"2026-01-21T07:12:41+00:00","og_image":[{"width":1024,"height":494,"url":"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/09\/unnamed-2.png","type":"image\/png"}],"twitter_card":"summary_large_image","twitter_misc":{"\u9810\u4f30\u95b1\u8b80\u6642\u9593":"3 \u5206\u9418"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/lightingrecipe.com\/flicker-pstlm-and-svm\/","url":"https:\/\/lightingrecipe.com\/flicker-pstlm-and-svm\/","name":"Flicker, PstLM, and SVM -","isPartOf":{"@id":"https:\/\/lightingrecipe.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/lightingrecipe.com\/flicker-pstlm-and-svm\/#primaryimage"},"image":{"@id":"https:\/\/lightingrecipe.com\/flicker-pstlm-and-svm\/#primaryimage"},"thumbnailUrl":"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/09\/unnamed-2.png","datePublished":"2026-01-13T07:35:36+00:00","dateModified":"2026-01-21T07:12:41+00:00","breadcrumb":{"@id":"https:\/\/lightingrecipe.com\/flicker-pstlm-and-svm\/#breadcrumb"},"inLanguage":"zh-TW","potentialAction":[{"@type":"ReadAction","target":["https:\/\/lightingrecipe.com\/flicker-pstlm-and-svm\/"]}]},{"@type":"ImageObject","inLanguage":"zh-TW","@id":"https:\/\/lightingrecipe.com\/flicker-pstlm-and-svm\/#primaryimage","url":"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/09\/unnamed-2.png","contentUrl":"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/09\/unnamed-2.png"},{"@type":"BreadcrumbList","@id":"https:\/\/lightingrecipe.com\/flicker-pstlm-and-svm\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/lightingrecipe.com\/"},{"@type":"ListItem","position":2,"name":"Flicker, PstLM, and SVM"}]},{"@type":"WebSite","@id":"https:\/\/lightingrecipe.com\/#website","url":"https:\/\/lightingrecipe.com\/","name":"","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/lightingrecipe.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"zh-TW"}]}},"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages\/2614","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/comments?post=2614"}],"version-history":[{"count":2,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages\/2614\/revisions"}],"predecessor-version":[{"id":2686,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages\/2614\/revisions\/2686"}],"wp:attachment":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/media?parent=2614"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}