{"id":12501,"date":"2022-06-29T01:00:40","date_gmt":"2022-06-29T01:00:40","guid":{"rendered":"http:\/\/nami.ai\/?p=12501"},"modified":"2024-05-26T17:39:28","modified_gmt":"2024-05-26T17:39:28","slug":"pir-sensors-passive-infrared-sensors","status":"publish","type":"post","link":"https:\/\/nami.ai\/blog\/pir-sensors-passive-infrared-sensors\/","title":{"rendered":"What Are PIR (Passive Infrared) Motion Sensors?"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"12501\" class=\"elementor elementor-12501\" data-elementor-post-type=\"post\">\n\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-62c924f elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"62c924f\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-955f190\" data-id=\"955f190\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-fe7316a elementor-widget elementor-widget-shortcode\" data-id=\"fe7316a\" data-element_type=\"widget\" data-widget_type=\"shortcode.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-shortcode\">\t\t<div data-elementor-type=\"section\" data-elementor-id=\"13120\" class=\"elementor elementor-13120\" data-elementor-post-type=\"elementor_library\">\n\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-99f35f8 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"99f35f8\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-1447f89\" data-id=\"1447f89\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-3041109e elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"3041109e\" data-element_type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-568aca68\" data-id=\"568aca68\" data-element_type=\"column\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-19ebe84f elementor-widget elementor-widget-heading\" data-id=\"19ebe84f\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><b>Key Takeaways<\/b><\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-7a32eccc elementor-widget elementor-widget-text-editor\" data-id=\"7a32eccc\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<ul><li>Passive infrared sensors (PIR sensors) are a longstanding motion detection technology, originating in the early 70s. experiments with radar and related technologies.<\/li><li>Benefits of PIR sensors include their affordability, ease of installation and energy efficiency.\u00a0<\/li><li>Disadvantages of PIR sensors include their inaccuracy compared to intelligent sensing technologies (e.g., radar sensing or WiFi sensing), and their inability to detect fine-grained motion.\u00a0<\/li><li>Over time, it is likely that PIR sensors will become supplanted by newer motion detection technologies.\u00a0<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-5a2e1f4b elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"5a2e1f4b\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-6ef52f\" data-id=\"6ef52f\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-12da6e2f elementor-widget elementor-widget-text-editor\" data-id=\"12da6e2f\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Passive infrared sensors (PIR sensors) are not just a theoretical concept; they are practical tools widely used in our devices and homes. With motion detection options available in the home, it is worth considering the benefits of PIR sensors and how they measure up against competing sensing technologies.<\/p><h2>What is Infrared Radiation?\u00a0<\/h2><p>Any object with a temperature higher than absolute zero emits heat energy as electromagnetic radiation. This is not visible to the human eye, but we feel it near a hot object.\u00a0<\/p><p>Infrared is on the same electromagnetic spectrum as visible light, which ranges from gamma rays and X-rays to microwaves and radio waves. It sits next to visible light on that spectrum, a wavelength humans can (at least sometimes) detect with their ordinary senses. As a form of ‘light’ that cannot be seen with the human eye, infrared is sometimes called ‘infrared light’.\u00a0<\/p><p>In 1800, thermometer experiments by the Astronomer\u00a0<a href=\"https:\/\/www.americanscientist.org\/article\/herschel-and-the-puzzle-of-infrared\" target=\"_blank\" rel=\"noopener\">Sir William Herschel<\/a> determined that infrared radiation is invisible radiation, lower in energy than red light. After Herschel’s studies, it was determined that more than half of the sun’s energy arrives on Earth in the form of infrared radiation.\u00a0<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-43255dba elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"43255dba\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-7d5597c4\" data-id=\"7d5597c4\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-20fae81c elementor-widget elementor-widget-text-editor\" data-id=\"20fae81c\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<h2>From Infrared to Passive Infrared: PIR Sensors Defined\u00a0<\/h2><p>Motion detection using sensing electromagnetic radiation goes back to the earliest forms of radar in the 19th century: Physicist Heinrich Hertz recognized that electromagnetic waves bounced off objects and moved at different speeds.\u00a0<\/p><p>In the early 70s, the first ‘<a href=\"https:\/\/patentimages.storage.googleapis.com\/31\/5d\/16\/2a3fe99c3a12e6\/US3703718.pdf\" target=\"_blank\" rel=\"noopener\">infrared detection intrusion system<\/a>‘ was patented by Herbert L Berman. This is the first example of a passive infrared (PIR) sensor: Motion is detected by sensing the change in the surrounding thermal radiation caused by movement. The sensors are \u2018passive\u2019 infrared as they do not \u2018emit\u2019 any thermal radiation themselves.<\/p><figure id=\"attachment_24767\" aria-describedby=\"caption-attachment-24767\" style=\"width: 388px\" class=\"wp-caption aligncenter\"><img fetchpriority=\"high\" decoding=\"async\" class=\"wp-image-24767 \" src=\"http:\/\/nami.ai\/wp-content\/uploads\/2024\/05\/pir-sensor-module.jpg\" alt=\"PIR Sensor Module \" width=\"388\" height=\"388\" srcset=\"https:\/\/nami.ai\/wp-content\/uploads\/2024\/05\/pir-sensor-module.jpg 800w, https:\/\/nami.ai\/wp-content\/uploads\/2024\/05\/pir-sensor-module-300x300.jpg 300w, https:\/\/nami.ai\/wp-content\/uploads\/2024\/05\/pir-sensor-module-150x150.jpg 150w, https:\/\/nami.ai\/wp-content\/uploads\/2024\/05\/pir-sensor-module-768x768.jpg 768w\" sizes=\"(max-width: 388px) 100vw, 388px\" \/><figcaption id=\"caption-attachment-24767\" class=\"wp-caption-text\">A PIR Sensor Module<\/figcaption><\/figure><p>In its modern incarnation, PIR sensors operate via two pyroelectric sensors that sit within a plastic housing and detect the ambient heat energy. The sensors contain a crystal surface that generates an electric charge when exposed to ambient infrared radiation.\u00a0 When the quantity of radiation hitting the crystal changes, the electric charge is also picked up by a device built into the sensor.<\/p><p>The sensor surfaces themselves can be ‘tweaked’ to limit the detectable change in radiation to the 8 to 14mm range\u2014the range most sensitive to human body radiation.<\/p><p>Depending on the setup of the PIR sensor, the change in electric charge detected in the sensor will trigger a certain event, such as an alarm sounding, turning on a light, or notifying the authorities.<\/p><p>These sensors can be \u2018binary\u2019\u2014detecting only the presence or absence of movement\u2014or they can be designed with sensitivity levels to detect the level of movement.<\/p><p>PIR can be contrasted with \u2018active\u2019 IR sensors. In an active sensor, an emitter sends infrared energy to a receiver. The default state is for the \u2018beam\u2019 to be received, indicating that nothing is blocking its path. Where the beam is interrupted, this indicates that motion is present.\u00a0<\/p><h2>What Are the Benefits of PIR Sensors?<\/h2><p>PIR sensors are a long-standing mechanism for motion detection for good reason. They are:<\/p><ul><li><strong>Affordable<br \/><\/strong>PIR sensors are constructed of easily sourced materials and do not rely on sophisticated hardware. Indoor units can cost as little as $5-10.<br \/><br \/><\/li><li><strong>Easy-to-install<br \/><\/strong>Ready out of the box, generally professional installation is not required.<br \/><br \/><\/li><li><strong>Energy-efficient<br \/><\/strong>Due to the \u2018passive\u2019 nature of the PIR mechanism, little energy is consumed \u2014 around <a href=\"https:\/\/www.thehomehacksdiy.com\/how-much-electricity-power-do-motion-sensors-use\/\" target=\"_blank\" rel=\"noopener\">one watt-hour per day<\/a> when on ‘standby’. For this reason, it is becoming increasingly common for PIR sensors to be powered by solar energy.<br \/><br \/><\/li><li><strong>Privacy<br \/><\/strong>As PIR sensors only detect changes in heat energy, no personal data is collected through motion detection.\u00a0<\/li><\/ul><h2>What Are Some of the typical Applications of PIR sensors?<\/h2><p>PIR sensors have a range of applications including:\u00a0<\/p><ul><li><strong>Automatically switching on lights<br \/><\/strong>In addition to the added convenience, PIR-managed lighting can be part of efficient home energy <strong>management \u2014 no lights are left on unnecessarily.<br \/><br \/><\/strong><\/li><li><strong>Home security<br \/><\/strong>As mentioned, PIR sensors can act as standalone intruder detectors or can be integrated with other home security technologies (for example, turning on surveillance cameras).<br \/><br \/><\/li><li><strong>Thermostats and HVAC systems<br \/><\/strong>PIR sensors can trigger these devices, further contributing to home energy efficiency.\u00a0<\/li><\/ul><h2>What Are the Disadvantages of PIR Sensors?<\/h2><p>Despite their benefits, there are some disadvantages to PIR sensors, which mean they may not always be appropriate:<\/p><ul><li><strong>False<\/strong>\u00a0<strong>positives<br \/><\/strong>As mentioned, modern PIR sensors are usually sensitivity-adjusted to capture the best human motion rather than the wind or a tree branch. Nevertheless, by their nature, PIR sensors are ‘broad brush’ and cannot distinguish human motion from animal motion in the way that intelligent sensing solutions can.<br \/><br \/><\/li><li><strong>False negatives<br \/><\/strong>Movement can be \u2018cloaked\u2019 to avoid PIR detection (for example, using heat blankets). Similarly, glass or other physical barriers can prevent PIR sensors from working effectively. In addition, PIR is inaccurate regarding stationary objects and ones that move slowly.<br \/><br \/><\/li><li><strong>Binary operation<br \/><\/strong>PIR sensors detect the absence or presence of motion. They cannot analyze fine-grained motion in the way that radar or WiFi sensing solutions can.<br \/><br \/><\/li><li><strong>Weather disturbances<br \/><\/strong>The weather substantially affects PIR sensors and can be less effective in hot and humid weather, where ambient heat energy is closer to human temperatures.\u00a0<\/li><\/ul><p>Below, we consider how PIR measures against other standard motion detection\/sensing technologies.<\/p><h2>PIR Sensors vs Cameras<\/h2><p>PIR and cameras are some of the more common motion detection technologies available. It is common for cameras to be fitted with PIR sensors to detect motion and \u2018turn on\u2019 the camera initially. Nevertheless, they are distinct ways of detecting motion (cameras can achieve this on their own through the application of pattern recognition software), and it is worth considering how they measure up against each other.\u00a0<\/p><p>What PIR and cameras have in common is being ‘line of sight’ technologies: They both identify motion that is in front of the sensor but struggle to sense motion around it (such as around corners and behind walls).\u00a0<\/p><p>Potential advantages of PIR sensors over cameras include:\u00a0<\/p><ul><li><strong>PIR is usually cheaper<br \/><\/strong>Due to their technological simplicity, installing multiple PIR units is usually much cheaper than installing multiple high-quality cameras.<br \/><br \/><\/li><li><strong>PIR works equally well in the dark<br \/><\/strong>While camera technology can also be adapted for night usage, motion identification is still more difficult. This is not a problem for PIR sensors as they do not rely on visibility.<br \/><br \/><\/li><li><strong>PIR protects the privacy of home occupants<br \/><\/strong>PIR protects the privacy of home occupants by detecting changes in thermal energy only; it doesn’t collect personal data. By contrast, cameras detect and potentially record detailed information about anyone who walks in front of them.<\/li><\/ul><p>On the other hand, potential disadvantages that PIR sensors can have compared to video cameras include:\u00a0<\/p><ul><li><strong>They are affected by temperature and weather<br \/><\/strong>PIR can be less effective at high temperatures, as the difference between the ambient temperature and the body is relatively small. Cameras have no such problem.<br \/><br \/><\/li><li><strong>PIR does not capture fine-grained data<br \/><\/strong>PIR detects an individual’s presence, but it does not capture information about micro-movements in the way cameras with an appropriate machine-learning algorithm can.\u00a0<\/li><\/ul><h2>PIR Sensors vs Radar Sensing\u00a0<\/h2><p>Radar sensing, like PIR and many other sensing technologies, interprets waves on the electromagnetic spectrum and how they are disrupted to detect movement. It transmits microwave signals in the direction of an object and then detects the radiation that is ‘backscattered’ from that object. You can read more about it <a href=\"http:\/\/nami.ai\/blog\/mmwave-radar-sensing\/\">here<\/a>.\u00a0\u00a0<\/p><p>As with PIR, radar sensing:\u00a0<\/p><ul><li><strong>Protects the privacy of occupants<br \/><\/strong>As only disturbances in electromagnetic radiation are detected, no personal information is collected or used.<br \/><br \/><\/li><li><strong>Uses little energy<br \/><\/strong>Depending on the complexity of the radar sensing equipment, both PIR and radar sensing use relatively little energy. Though radar sensing is an ‘active’ form of motion detection, it is usually used more.\u00a0<\/li><\/ul><p>Compared to radar sensing, PIR is:\u00a0<\/p><ul><li><strong>More affordable<br \/><\/strong>Radar sensing generally requires multiple antennae and a more complex printed circuit board (PCB) to detect motion.<br \/><br \/><\/li><li><strong>Simple to install<br \/><\/strong>While the technology is increasingly user-friendly, radar sensing requires professional installation.\u00a0<\/li><\/ul><p>On the other hand:<\/p><ul><li><strong>PIR is less accurate than radar sensing<br \/><\/strong>\u00a0Radar sensing can pick up micro-movements that PIR will miss, distinguish different animal types, and is not substantially affected by the weather.<br \/><br \/><\/li><li><strong>PIR is line-of-sight only<\/strong>\u00a0<br \/>Radar sensing can detect motion around corners and through walls.<\/li><\/ul><h2>PIR Sensors vs WiFi Sensing<\/h2><p><a href=\"http:\/\/nami.ai\/blog\/what-is-wi-fi-sensing\/\">WiFi sensing<\/a>\u00a0uses the power of local wireless networks (i.e., ‘WiFi’) to detect motion. This has applications for home security, sustainable energy use, and monitoring vulnerable family members. As with PIR sensors, WiFi sensing is:\u00a0<\/p><ul><li><strong>Affordable<br \/><\/strong>Using similar technology to existing WiFi devices, WiFi sensing does not require expensive hardware.<br \/><br \/><\/li><li><a href=\"http:\/\/nami.ai\/privacy-by-design\/\"><strong>Respectful of occupant privacy<\/strong><\/a><br \/>No personal data is necessary for WiFi sensing to function.<br \/><br \/><\/li><li><strong>Easy-to-install<br \/><\/strong>WiFi sensing solutions are often available in ‘plug and play’ hardware without the need to hire professionals.\u00a0<\/li><\/ul><p>However, there are a range of ways in which PIR sensors are less effective than WiFi sensing:\u00a0<\/p><ul><li><strong>False positives<\/strong>\u00a0<br \/>WiFi sensing can filter out non-human movement, such as pets. However, most PIR sensors are unable to eliminate these false positives.<br \/><br \/><\/li><li><strong>Coverage<br \/><\/strong>WiFi sensing can cover larger areas than PIR sensors.\u00a0\u00a0<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-4c17164a elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"4c17164a\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-25d8a3b0\" data-id=\"25d8a3b0\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-4701f27d elementor-widget elementor-widget-text-editor\" data-id=\"4701f27d\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<h2>Conclusion<\/h2><p>PIR sensors detect the difference between ambient heat energy and the heat energy generated by objects to detect motion. They are affordable, straightforward, and have an established history as a motion detection technology. However, PIR lacks the accuracy of newer sensing technologies, such as radar and WiFi, and is therefore likely to be replaced by ‘<a href=\"http:\/\/nami.ai\/wifi-presence-sensing\/\" target=\"_blank\" rel=\"noopener\">Sensing 2.0<\/a>‘ technologies over time.\u00a0<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-7fd1e0d7 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"7fd1e0d7\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-71bafd11\" data-id=\"71bafd11\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-147fcb63 elementor-widget elementor-widget-heading\" data-id=\"147fcb63\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">FAQ<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-988cd52 elementor-widget elementor-widget-accordion\" data-id=\"988cd52\" data-element_type=\"widget\" data-widget_type=\"accordion.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-accordion\">\n\t\t\t\t\t\t\t<div class=\"elementor-accordion-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1591\" class=\"elementor-tab-title\" data-tab=\"1\" role=\"button\" aria-controls=\"elementor-tab-content-1591\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon elementor-accordion-icon-right\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-closed\"><svg class=\"e-font-icon-svg e-fas-plus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H272V64c0-17.67-14.33-32-32-32h-32c-17.67 0-32 14.33-32 32v144H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h144v144c0 17.67 14.33 32 32 32h32c17.67 0 32-14.33 32-32V304h144c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-opened\"><svg class=\"e-font-icon-svg e-fas-minus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h384c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-accordion-title\" tabindex=\"0\">What Do PIR Sensors Do?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<div id=\"elementor-tab-content-1591\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"1\" role=\"region\" aria-labelledby=\"elementor-tab-title-1591\"><p>Passive infrared (PIR) sensors detect motion by sensing the difference between ambient heat energy in a location, and the heat energy when a moving object has entered into that space.\u00a0<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<div class=\"elementor-accordion-item\">\n\t\t\t\t\t<div id=\"elementor-tab-title-1592\" class=\"elementor-tab-title\" data-tab=\"2\" role=\"button\" aria-controls=\"elementor-tab-content-1592\" aria-expanded=\"false\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon elementor-accordion-icon-right\" aria-hidden=\"true\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-closed\"><svg class=\"e-font-icon-svg e-fas-plus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H272V64c0-17.67-14.33-32-32-32h-32c-17.67 0-32 14.33-32 32v144H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h144v144c0 17.67 14.33 32 32 32h32c17.67 0 32-14.33 32-32V304h144c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t<span class=\"elementor-accordion-icon-opened\"><svg class=\"e-font-icon-svg e-fas-minus\" viewBox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M416 208H32c-17.67 0-32 14.33-32 32v32c0 17.67 14.33 32 32 32h384c17.67 0 32-14.33 32-32v-32c0-17.67-14.33-32-32-32z\"><\/path><\/svg><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"elementor-accordion-title\" tabindex=\"0\">What Is the Difference Between PIR and IR Sensors<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<div id=\"elementor-tab-content-1592\" class=\"elementor-tab-content elementor-clearfix\" data-tab=\"2\" role=\"region\" aria-labelledby=\"elementor-tab-title-1592\"><p>PIR sensors are passive, which means they do not emit infrared waves themselves, but instead sense changes in the surrounding thermal energy. By contrast, active infrared sensors emit infrared waves and interpret the way in which those waves ‘bounce’ off moving objects.\u00a0<\/p><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t<script type=\"application\/ld+json\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"What Do PIR Sensors Do?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<p>Passive infrared (PIR) sensors detect motion by sensing the difference between ambient heat energy in a location, and the heat energy when a moving object has entered into that space.\\u00a0<\\\/p>\"}},{\"@type\":\"Question\",\"name\":\"What Is the Difference Between PIR and IR Sensors\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"<p>PIR sensors are passive, which means they do not emit infrared waves themselves, but instead sense changes in the surrounding thermal energy. By contrast, active infrared sensors emit infrared waves and interpret the way in which those waves ‘bounce’ off moving objects.\\u00a0<\\\/p>\"}}]}<\/script>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Key Takeaways Passive infrared sensors (PIR sensors) are a longstanding motion detection technology, originating in the early 70s. experiments with radar and related technologies. Benefits of PIR sensors include their affordability, ease of installation and energy efficiency.\u00a0 Disadvantages of PIR sensors include their inaccuracy compared to intelligent sensing technologies (e.g., radar sensing or WiFi sensing), [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":10240,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[43],"tags":[],"class_list":["post-12501","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-sensing"],"_links":{"self":[{"href":"https:\/\/nami.ai\/wp-json\/wp\/v2\/posts\/12501","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nami.ai\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nami.ai\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nami.ai\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nami.ai\/wp-json\/wp\/v2\/comments?post=12501"}],"version-history":[{"count":0,"href":"https:\/\/nami.ai\/wp-json\/wp\/v2\/posts\/12501\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nami.ai\/wp-json\/wp\/v2\/media\/10240"}],"wp:attachment":[{"href":"https:\/\/nami.ai\/wp-json\/wp\/v2\/media?parent=12501"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nami.ai\/wp-json\/wp\/v2\/categories?post=12501"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nami.ai\/wp-json\/wp\/v2\/tags?post=12501"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}