{"id":25996,"date":"2026-06-27T14:49:54","date_gmt":"2026-06-27T12:49:54","guid":{"rendered":"https:\/\/roder.it\/products\/optical-encoder-speed-meters\/optical-speed-meters-series-vlm500\/"},"modified":"2026-10-05T16:04:43","modified_gmt":"2026-10-05T14:04:43","slug":"optical-speed-meters-series-vlm500","status":"publish","type":"page","link":"https:\/\/roder.it\/en\/products\/optical-encoder-speed-meters\/optical-speed-meters-series-vlm500\/","title":{"rendered":"Optical speed meters series VLM500"},"content":{"rendered":"\n<div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\">\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-7387b849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:50%\">\n<figure class=\"wp-block-image size-full\" style=\"margin-right:var(--wp--preset--spacing--20);margin-left:var(--wp--preset--spacing--20)\"><img loading=\"lazy\" decoding=\"async\" width=\"510\" height=\"510\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm500_foto_prodotto_assonometria_vista-web_image-510x510-1.webp\" alt=\"ASTech VLM500 optical velocimeter encoder for non-contact measurement of speed and length\" class=\"wp-image-14956\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm500_foto_prodotto_assonometria_vista-web_image-510x510-1.webp 510w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm500_foto_prodotto_assonometria_vista-web_image-510x510-1-300x300.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm500_foto_prodotto_assonometria_vista-web_image-510x510-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm500_foto_prodotto_assonometria_vista-web_image-510x510-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 510px) 100vw, 510px\" \/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:50%\">\n<h3 class=\"wp-block-heading has-text-color\" style=\"color:#f28c28\">Non-contact optical velocimeter and encoder for continuous measurement of speed and length on moving strips, sheets, tubes, wires and profiles.<\/h3>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Non-contact optical principle<\/strong> with spatial filter and CCD sensor<\/li>\n\n\n\n<li><strong>Speed up to 50 m\/s<\/strong> (up to 3000 m\/min in the extended range)<\/li>\n\n\n\n<li><strong>Measurement uncertainty &lt; 0.025 %<\/strong> at the nominal distance<\/li>\n\n\n\n<li><strong>Slip-free measurement<\/strong>, with no wear and no maintenance<\/li>\n\n\n\n<li><strong>White-light LED illumination<\/strong>, with no harmful LASER light<\/li>\n\n\n\n<li><strong>Working distances<\/strong> 185 \/ 240 \/ 330 mm depending on the version<\/li>\n\n\n\n<li><strong>Multiple industrial interfaces<\/strong> and pulse encoder output<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n<div class=\"wp-block-cover is-light popmake-11245\" style=\"border-width:1px;border-top-left-radius:10px;border-top-right-radius:10px;border-bottom-left-radius:10px;border-bottom-right-radius:10px;min-height:250px;aspect-ratio:unset;\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"213\" class=\"wp-block-cover__image-background wp-image-14896 size-large\" alt=\"banner aiuto nella scelta dello strumento oppure della tecnologia\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/banner_technical_support_choose_products-1024x213.png\" data-object-fit=\"cover\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/banner_technical_support_choose_products-1024x213.png 1024w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/banner_technical_support_choose_products-300x63.png 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/banner_technical_support_choose_products-768x160.png 768w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/banner_technical_support_choose_products.png 1200w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-background-dim\" style=\"background-color:#d3d6dc\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-container-core-cover-is-layout-a304f9a9 wp-block-cover-is-layout-constrained\">\n<p class=\"has-text-align-right has-ti-fg-color has-text-color has-link-color wp-elements-1 wp-block-paragraph\" style=\"font-size:clamp(21.536px, 1.346rem + ((1vw - 3.2px) * 1.726), 35px);\"><strong>Would you like help choosing the right product ?<\/strong><\/p>\n\n\n\n<div class=\"wp-block-buttons is-content-justification-right is-layout-flex wp-container-core-buttons-is-layout-b507c051 wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/roder.it\/en\/contacts\/\">Click here !<\/a><\/div>\n<\/div>\n<\/div><\/div>\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n<h4 class=\"wp-block-heading has-ti-accent-color has-text-color\">Why choose the VLM500<\/h4>\n\n<ul class=\"wp-block-list is-style-checkbox\">\n<li><strong>Non-contact and slip-free measurement<\/strong>: the spatial filter optical principle eliminates the errors typical of measuring wheels, eliminating mechanical wear and maintenance.<\/li>\n\n\n\n<li><strong>High accuracy<\/strong>: measurement uncertainty &lt; 0.025 % at the nominal distance, &lt; 0.05 % in the working range and &lt; 0.2 % in the extended working range; reproducibility &lt; 0.025 %.<\/li>\n\n\n\n<li><strong>Almost independent of the material<\/strong>: measures on almost all surfaces (metal, paper, textiles, plastic, ceramics, wood, rubber) thanks to the automatic adjustment of exposure time and brightness.<\/li>\n\n\n\n<li><strong>Robust and compact construction<\/strong>: IP 65 housing, insensitive to contamination, for safe and space-saving installations in industrial environments.<\/li>\n\n\n\n<li><strong>Flexible integration<\/strong>: available with various industrial interfaces (RS232, RS422\/485, USB, Profibus DP, Profinet IO, EtherNet\/IP), pulse encoder output and analogue output.<\/li>\n\n\n\n<li><strong>Long-term reliability<\/strong>: expected life &gt; 15 years, 60-month warranty, Made in Germany.<\/li>\n<\/ul>\n\n<p class=\"wp-block-paragraph\">The <strong>VLM500<\/strong> is a non-contact optical velocimeter and encoder for continuous measurement of the <strong>speed and length<\/strong> of moving objects. It works according to the <strong>spatial filter principle<\/strong>: the surface of the material is illuminated by an integrated white-light LED and the reflected light, modulated by the granular structure of the surface, is detected by a CCD sensor. The resulting frequency is proportional to the speed of the object; the length is obtained by integration over time.  <\/p>\n\n<p class=\"wp-block-paragraph\">Since the measurement is made without contact and without slippage, the VLM500 eliminates the wear and errors typical of measuring wheels. The rapid automatic adjustment of exposure time and brightness makes it possible to measure on almost all surfaces, making the instrument suitable for many industrial sectors: <strong>metal, paper, wood, ceramics, textiles, plastic and rubber<\/strong>. <\/p>\n\n<p class=\"wp-block-paragraph\">The compactness and robustness of the housing (IP 65) allow safe and space-saving installations. Depending on requirements, the VLM500 can be equipped with various industrial interfaces, pulse outputs and an analogue output, for integration into the automation systems of winders, cutting lines, coating and inspection lines, paper machines and extruders. <\/p>\n\n<h2 class=\"wp-block-heading\">Technical documentation<\/h2>\n\n<figure class=\"wp-block-table is-style-stripes\"><table class=\"has-fixed-layout\"><tbody><tr><td><a href=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-velocimetro_encoder_ottico_vlm500_datasheet_en_v23-datasheet.pdf\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/icona_pdf_download.webp\" alt=\"Scarica PDF\" width=\"48\" height=\"61\" class=\"wp-image-14977\" \/><\/a><\/td><td><a href=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-velocimetro_encoder_ottico_vlm500_datasheet_en_v23-datasheet.pdf\" target=\"_blank\" rel=\"noopener\"><strong>VLM500 datasheet<\/strong><\/a><\/td><td>Datasheet<\/td><\/tr><tr><td><a href=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-velocimetro_encoder_ottico_vlm500_manuale_en_v28-manual.pdf\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/icona_pdf_download.webp\" alt=\"Scarica PDF\" width=\"48\" height=\"61\" class=\"wp-image-14977\" \/><\/a><\/td><td><a href=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-velocimetro_encoder_ottico_vlm500_manuale_en_v28-manual.pdf\" target=\"_blank\" rel=\"noopener\"><strong>VLM500 manual<\/strong><\/a><\/td><td>Manual<\/td><\/tr><tr><td><a href=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-velocimetro_encoder_ottico_vlm500_manuale_versione_speciale_dg_en_v17-manual.pdf\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/icona_pdf_download.webp\" alt=\"Scarica PDF\" width=\"48\" height=\"61\" class=\"wp-image-14977\" \/><\/a><\/td><td><a href=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-velocimetro_encoder_ottico_vlm500_manuale_versione_speciale_dg_en_v17-manual.pdf\" target=\"_blank\" rel=\"noopener\"><strong>VLM500 manual, DG special version<\/strong><\/a><\/td><td>Manual<\/td><\/tr><\/tbody><\/table><\/figure>\n\n<h2 class=\"wp-block-heading\">Operating principle<\/h2>\n\n<div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\">\n<figure class=\"wp-block-image alignleft size-full is-resized\" style=\"margin-right:40px;margin-bottom:30px\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"1200\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-schema_principio_funzionamento_vlm500-web_image-1200x1200-1.webp\" alt=\"Diagram of the spatial filter operating principle of the VLM500 optical velocimeter\" class=\"wp-image-14946\" style=\"width:420px;height:auto\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-schema_principio_funzionamento_vlm500-web_image-1200x1200-1.webp 1200w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-schema_principio_funzionamento_vlm500-web_image-1200x1200-1-300x300.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-schema_principio_funzionamento_vlm500-web_image-1200x1200-1-1024x1024.webp 1024w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-schema_principio_funzionamento_vlm500-web_image-1200x1200-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-schema_principio_funzionamento_vlm500-web_image-1200x1200-1-768x768.webp 768w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-schema_principio_funzionamento_vlm500-web_image-1200x1200-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The VLM500 is based on the <strong>spatial filter principle<\/strong>. The light from a white-light LED illuminates the surface of the moving object; the reflected light, modulated by the morphology (granularity) of the surface, is projected onto a <strong>CCD sensor<\/strong> that acts as a reference grating. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The movement of the material generates a signal whose <strong>frequency is proportional to the speed<\/strong>. The length is calculated by integrating the speed over time. Internal control loops automatically adjust exposure time and brightness, ensuring rapid adaptation to different surface conditions and a measurement that is practically independent of the material.  <\/p>\n<\/div>\n\n<h2 class=\"wp-block-heading\">Available versions<\/h2>\n\n<p class=\"wp-block-paragraph\">The VLM500 is available in four versions that differ in working distance and measuring range, to suit different installation geometries and line speeds.<\/p>\n\n<figure class=\"wp-block-table alignwide is-style-stripes\"><table><thead><tr><th class=\"has-text-align-left\" data-align=\"left\">Version<\/th><th class=\"has-text-align-left\" data-align=\"left\">Nominal distance and working range<\/th><th class=\"has-text-align-left\" data-align=\"left\">Measuring range<\/th><th class=\"has-text-align-left\" data-align=\"left\">Measuring range (extended range)<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-left\" data-align=\"left\">VLM500A<\/td><td class=\"has-text-align-left\" data-align=\"left\">185 \u00b1 15 mm<\/td><td class=\"has-text-align-left\" data-align=\"left\">0.6 \u2026 2200 m\/min<\/td><td class=\"has-text-align-left\" data-align=\"left\">1.2 \u2026 3000 m\/min<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">VLM500D<\/td><td class=\"has-text-align-left\" data-align=\"left\">240 \u00b1 15 mm<\/td><td class=\"has-text-align-left\" data-align=\"left\">0.18 \u2026 1200 m\/min<\/td><td class=\"has-text-align-left\" data-align=\"left\">0.72 \u2026 2400 m\/min<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">VLM500L<\/td><td class=\"has-text-align-left\" data-align=\"left\">185 \u00b1 10 mm<\/td><td class=\"has-text-align-left\" data-align=\"left\">0.12 \u2026 250 m\/min<\/td><td class=\"has-text-align-left\" data-align=\"left\">0.30 \u2026 600 m\/min<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">VLM500E<\/td><td class=\"has-text-align-left\" data-align=\"left\">330 \u00b1 30 mm<\/td><td class=\"has-text-align-left\" data-align=\"left\">0.60 \u2026 2000 m\/min<\/td><td class=\"has-text-align-left\" data-align=\"left\">1.00 \u2026 2700 m\/min<\/td><\/tr><\/tbody><\/table><\/figure>\n\n<div class=\"wp-block-columns are-vertically-aligned-center is-layout-flex wp-container-core-columns-is-layout-7387b849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:30%\">\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"384\" height=\"384\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm502_versione_500_testina_compatta-web_image-384x384-1.webp\" alt=\"VLM502 compact version of the VLM500 series\" class=\"wp-image-14955\" style=\"width:200px;height:auto\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm502_versione_500_testina_compatta-web_image-384x384-1.webp 384w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm502_versione_500_testina_compatta-web_image-384x384-1-300x300.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm502_versione_500_testina_compatta-web_image-384x384-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm502_versione_500_testina_compatta-web_image-384x384-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 384px) 100vw, 384px\" \/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:70%\">\n<p class=\"wp-block-paragraph\">The <strong>VLM502<\/strong> version with compact head is also available, designed for installations with limited space, while keeping the same optical measuring principle as the VLM500 series.<\/p>\n<\/div>\n<\/div>\n\n<h2 class=\"wp-block-heading\">Technical specifications<\/h2>\n\n<figure class=\"wp-block-table alignwide is-style-stripes\"><table><tbody><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Measuring principle<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">Non-contact optical, spatial filter with CCD sensor<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Maximum speed<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">up to 50 m\/s<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Measurement uncertainty<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">&lt; 0.025 % at the nominal distance; &lt; 0.05 % in the working range; &lt; 0.2 % in the extended range<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Reproducibility<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">&lt; 0.025 %<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Update time<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">&gt; 0.2 ms, with additional moving average 1 \u2026 32 times<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Length measuring range<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">internal up to 2,000,000 km<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Lighting<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">White-light LED (no LASER light)<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Power supply<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">24 VDC, max 25 W<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Operating temperature<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">0 \u00b0C \u2026 50 \u00b0C<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Degree of protection<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">IP 65<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Weight and dimensions<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">approx. 3.6 kg; 260 \u00d7 160 \u00d7 90 mm (without connections)<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Programming interfaces<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">USB, RS-232, RS-422\/RS-485 (isolated)<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Pulse output (encoder)<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">A\/B, 2 phases 90\u00b0, resolution 8 ns, 0.2 Hz \u2026 25 kHz<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Analogue output<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">current, adjustable 0 \u2026 20 mA, 0 \u2026 24 mA, 4 \u2026 20 mA<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Fieldbus<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">Profibus DP, Profinet IO, EtherNet\/IP, Telnet\/UDP via Ethernet<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>EMC compliance<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">EN 61326-1 (group 1, class A)<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>Expected life \/ warranty<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">&gt; 15 years \/ 60 months \u2014 Made in Germany<\/td><\/tr><\/tbody><\/table><\/figure>\n\n<h2 class=\"wp-block-heading\">Applications<\/h2>\n\n<ul class=\"wp-block-list\">\n<li><strong>Length and speed measurement<\/strong> on winders, cutting (slitting) lines, coating and inspection lines<\/li>\n\n\n\n<li><strong>Steel and metallurgical industry<\/strong>: strips, sheets, wire rod, bars, tubes and drawn products, even when red-hot<\/li>\n\n\n\n<li><strong>Paper industry<\/strong>: speed measurement on stock, wire and sheet in paper machines<\/li>\n\n\n\n<li><strong>Extrusion<\/strong>: speed control and cut-to-length on extruded materials<\/li>\n\n\n\n<li><strong>Quality control and inspection<\/strong>: cutting, positioning, adjustment and dimensional verification of profiles, strips, sheets, cables and ropes<\/li>\n<\/ul>\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-7387b849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_metalli_materiali_siderurgici-web_image-300x300-1.webp\" alt=\"VLM500 application on metals and steel materials\" class=\"wp-image-14939\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_metalli_materiali_siderurgici-web_image-300x300-1.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_metalli_materiali_siderurgici-web_image-300x300-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_metalli_materiali_siderurgici-web_image-300x300-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_lamiera_elevata_velocita-web_image-300x300-1.webp\" alt=\"VLM500 application on sheet metal at high speed\" class=\"wp-image-14941\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_lamiera_elevata_velocita-web_image-300x300-1.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_lamiera_elevata_velocita-web_image-300x300-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_lamiera_elevata_velocita-web_image-300x300-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_vergelle_tondini_incandescenti-web_image-300x300-1.webp\" alt=\"VLM500 application on red-hot wire rod and bars\" class=\"wp-image-14960\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_vergelle_tondini_incandescenti-web_image-300x300-1.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_vergelle_tondini_incandescenti-web_image-300x300-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_vergelle_tondini_incandescenti-web_image-300x300-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_trafilato_metallico_barre_tubi-web_image-300x300-1.webp\" alt=\"VLM500 application on drawn metal, bars and tubes\" class=\"wp-image-14964\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_trafilato_metallico_barre_tubi-web_image-300x300-1.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_trafilato_metallico_barre_tubi-web_image-300x300-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-appl_trafilato_metallico_barre_tubi-web_image-300x300-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div>\n<\/div>\n\n<h2 class=\"wp-block-heading\">Accessories<\/h2>\n\n<p class=\"wp-block-paragraph\">The VLM500 series can be completed with accessories for mounting, alignment, display and protection in harsh environments.<\/p>\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-7387b849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"453\" height=\"453\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-piastra_fissaggio_mpl1_encoder_ottici-web_image-453x453-1.webp\" alt=\"MPL1 mounting plate for VLM500\" class=\"wp-image-14949\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-piastra_fissaggio_mpl1_encoder_ottici-web_image-453x453-1.webp 453w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-piastra_fissaggio_mpl1_encoder_ottici-web_image-453x453-1-300x300.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-piastra_fissaggio_mpl1_encoder_ottici-web_image-453x453-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-piastra_fissaggio_mpl1_encoder_ottici-web_image-453x453-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 453px) 100vw, 453px\" \/><\/figure>\n\n\n\n<p class=\"has-text-align-center has-small-font-size wp-block-paragraph\">MPL1 mounting plate<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"453\" height=\"453\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-unita_allineamento_velocimetri_ottici-web_image-453x453-1.webp\" alt=\"Alignment unit for VLM500 optical velocimeters\" class=\"wp-image-14947\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-unita_allineamento_velocimetri_ottici-web_image-453x453-1.webp 453w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-unita_allineamento_velocimetri_ottici-web_image-453x453-1-300x300.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-unita_allineamento_velocimetri_ottici-web_image-453x453-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-unita_allineamento_velocimetri_ottici-web_image-453x453-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 453px) 100vw, 453px\" \/><\/figure>\n\n\n\n<p class=\"has-text-align-center has-small-font-size wp-block-paragraph\">Alignment unit<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"453\" height=\"453\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-unita_raffreddamento_pressurizzazione_ac5-web_image-453x453-1.webp\" alt=\"AC5 cooling and pressurisation unit for VLM500\" class=\"wp-image-14944\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-unita_raffreddamento_pressurizzazione_ac5-web_image-453x453-1.webp 453w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-unita_raffreddamento_pressurizzazione_ac5-web_image-453x453-1-300x300.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-unita_raffreddamento_pressurizzazione_ac5-web_image-453x453-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-unita_raffreddamento_pressurizzazione_ac5-web_image-453x453-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 453px) 100vw, 453px\" \/><\/figure>\n\n\n\n<p class=\"has-text-align-center has-small-font-size wp-block-paragraph\">AC5 cooling\/pressurisation<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"453\" height=\"453\" src=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-display_analogico_velocimentri_ottici-web_image-453x453-1.webp\" alt=\"Display for VLM500 optical velocimeters\" class=\"wp-image-14951\" srcset=\"https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-display_analogico_velocimentri_ottici-web_image-453x453-1.webp 453w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-display_analogico_velocimentri_ottici-web_image-453x453-1-300x300.webp 300w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-display_analogico_velocimentri_ottici-web_image-453x453-1-150x150.webp?crop=1 150w, https:\/\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-display_analogico_velocimentri_ottici-web_image-453x453-1-120x120.webp?crop=1 120w\" sizes=\"auto, (max-width: 453px) 100vw, 453px\" \/><\/figure>\n\n\n\n<p class=\"has-text-align-center has-small-font-size wp-block-paragraph\">External display<\/p>\n<\/div>\n<\/div>\n\n<h2 class=\"wp-block-heading\">Frequently asked questions<\/h2>\n\n<div class=\"schema-faq wp-block-yoast-faq-block\"><div class=\"schema-faq-section\" id=\"faq-vlm500-1\"><strong class=\"schema-faq-question\">How does the VLM500 measure speed without touching the material?<\/strong> <p class=\"schema-faq-answer\">The VLM500 uses the spatial filter optical principle: a white-light LED illuminates the surface and a CCD sensor detects the reflected light modulated by the granularity of the material. The frequency of the signal is proportional to the speed and the length is obtained by integration, with no contact or slippage. <\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-vlm500-2\"><strong class=\"schema-faq-question\">What is the accuracy of the VLM500?<\/strong> <p class=\"schema-faq-answer\">The measurement uncertainty is less than 0.025 % at the nominal working distance, less than 0.05 % in the working range and less than 0.2 % in the extended working range. Reproducibility is less than 0.025 %. <\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-vlm500-3\"><strong class=\"schema-faq-question\">On which materials can the VLM500 measure?<\/strong> <p class=\"schema-faq-answer\">Thanks to the automatic adjustment of exposure and brightness, the VLM500 measures on almost all surfaces and materials: metal, paper, textiles, plastic, ceramics, wood and rubber.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-vlm500-4\"><strong class=\"schema-faq-question\">Which interfaces and outputs are available?<\/strong> <p class=\"schema-faq-answer\">The VLM500 can be configured with USB, RS-232 and RS-422\/485 interfaces, Profibus DP, Profinet IO and EtherNet\/IP fieldbuses, as well as an A\/B pulse encoder output and an analogue current output (0\u202620 mA, 4\u202620 mA).<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-vlm500-5\"><strong class=\"schema-faq-question\">What are the versions of the VLM500 and how do they differ?<\/strong> <p class=\"schema-faq-answer\">The versions VLM500A, VLM500D, VLM500L and VLM500E are available, which differ in working distance (from 185 to 330 mm) and measuring range (from 0.12 up to 3000 m\/min in the extended range). The compact version VLM502 is also available. <\/p> <\/div> <\/div>\n\n<div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h4 class=\"wp-block-heading has-ti-accent-color has-text-color has-link-color wp-elements-2\">Contacts &amp; Information<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Contact for general information : <a href=\"mailto:info@roder.it\">info@roder.it<\/a><br\/><br\/>Machine Vision Division of RODER : <a href=\"http:\/\/www.rodervision.com\">www.rodervision.com<\/a><br\/>RODER Instruments Division : <a href=\"http:\/\/www.rodervision.com\">www.innovacheck.com<\/a><br\/>More about RODER : <a href=\"https:\/\/roder.it\/en\/contacts\/\">about us<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The information contained in this website is provided for information purposes only. Although it has been prepared with the greatest care, it does not constitute a contractual offer or a binding commitment to supply. It may contain transcription, translation or typographical errors. For precise and up-to-date information, please contact our company directly.   <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Note:<\/strong> Some images on this website have been intentionally generated using artificial intelligence (AI). This is because, for many applications and projects, photographs of the actual installation or system cannot be disclosed owing to confidentiality agreements, contractual clauses and non-disclosure agreements (NDAs). <\/p>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Non-contact optical velocimeter and encoder for continuous measurement of speed and length on moving strips, sheets, tubes, wires and profiles. Why choose the VLM500 The VLM500 is a non-contact optical velocimeter and encoder for continuous measurement of the speed and length of moving objects. It works according to the spatial filter principle: the surface of [&hellip;]<\/p>\n","protected":false},"author":157040980,"featured_media":0,"parent":18306,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_yoast_wpseo_focuskw":"","_yoast_wpseo_title":"","_yoast_wpseo_metadesc":"","_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_wpcom_ai_launchpad_about_page":false,"_wpcom_ai_launchpad_gallery_page":false,"_wpcom_ai_launchpad_contact_page":false,"_wpcom_ai_launchpad_events_page":false,"_wpcom_ai_launchpad_video_page":false,"_wpcom_ai_launchpad_portfolio_piece":false,"footnotes":""},"class_list":["post-25996","page","type-page","status-publish","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.6 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Optical speed meters series VLM500 - RODER SRL<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/roder.it\/en\/products\/optical-encoder-speed-meters\/optical-speed-meters-series-vlm500\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Optical speed meters series VLM500 - RODER SRL\" \/>\n<meta property=\"og:description\" content=\"Non-contact optical velocimeter and encoder for continuous measurement of speed and length on moving strips, sheets, tubes, wires and profiles. 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Why choose the VLM500 The VLM500 is a non-contact optical velocimeter and encoder for continuous measurement of the speed and length of moving objects. 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On this page we examine, from a technical standpoint, the principles on which ASTech optical speed meters and encoders are based: the spatial filter of the VLM500 series and\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"scanner laser misura di profilo e posizione","src":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2025\/02\/application_note_0001_scansione_laser_rilievo_posizione_aletta_per_saldatura_720x720.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2025\/02\/application_note_0001_scansione_laser_rilievo_posizione_aletta_per_saldatura_720x720.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2025\/02\/application_note_0001_scansione_laser_rilievo_posizione_aletta_per_saldatura_720x720.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2025\/02\/application_note_0001_scansione_laser_rilievo_posizione_aletta_per_saldatura_720x720.png?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":18306,"url":"https:\/\/roder.it\/en\/products\/optical-encoder-speed-meters\/","url_meta":{"origin":25996,"position":1},"title":"Optical encoder speed meters","author":"GSM","date":"27 June 2026","format":false,"excerpt":"Non-contact optical speed meters and encoders for the precise measurement of speed and length in continuous industrial processes. Optical encoder speed meters measure the speed and length of moving materials with no mechanical contact at all, eliminating the slip and wear typical of measuring wheels. RODER distributes the ASTech range\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"ASTECH VLM500: foto prodotto in assonometria, vista anteriore dell'encoder ottico","src":"https:\/\/i0.wp.com\/roder.it\/wp-content\/uploads\/2026\/06\/astech-velocimetri_ottici_vlm500-vlm500_foto_prodotto_assonometria_vista-web_image-510x510-1.webp?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":17941,"url":"https:\/\/roder.it\/en\/technologies\/","url_meta":{"origin":25996,"position":2},"title":"Technologies","author":"GSM","date":"29 June 2026","format":false,"excerpt":"Non-contact speed and length measurement is today a key technology for process control in many industrial sectors. 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