Lighting Design & Specification

May 8, 2018

Passive Infrared (PIR) sensors are widely used in smart lighting systems and save money by dramatically reducing lighting usage and energy consumption. They are employed in offices and classrooms as well as in spaces with intermittent and unpredictable lighting usage, such as corridors, stairwells, storage areas, and parking garages. Lights can be programmed to either “dim” or “switch” in response to an occupancy status signal from a sensor. The strategy also improves comfort for occupants as they never have to enter a dark area or manually turn lights on or off. 

How does a PIR sensor detect motion?

All objects, including those that are inanimate, emit heat energy in the form of infrared radiation. Humans, animals and plants generate stronger infrared signals than inanimate objects because they burn energy that generates heat to maintain (self-regulate) a particular temperature. 

PIR sensors measure infrared light radiating from objects in its view. Anything that moves in front of a PIR sensor with a temperature different than the background of the view area will trigger a pair of pyroelectric elements on the sensor to react to the change in temperature with instantaneous differences in output. These differences in output generate energy, which triggers the sensor to transmit a detection signal to the light(s) to turn on. Simply put, the sensor detects a motion that indicates an occupant is in the space and light(s) turn on. 

Equally important parts

There are two distinct parts of a PIR sensor: the sensor element and the cover or lens. The round metal sensor element is the sensor itself and it detects the level of infrared radiation. The cover or lens focuses the infrared signals on to the sensor. It determines the breadth of the sensing coverage area, the sensing range, and the sensing pattern. The lens is just as important, some would even say more important in some cases, than the sensor element. 

The lens can have multiple facets that each look for a heat signature, so the more facets the lens has, the denser the sensor’s coverage area, meaning that there is a higher probability that an object in motion will cross a sensor’s beam and trigger the sensor (and the light). Using the same sensor element with two different lenses will provide different detection patterns and coverage areas.

Shape of the coverage area

Sensors can have a long range or a short range. With the extended range, the facets view angle is wider (approximately 120-140 degrees), and with the short range or standard range, the facets view angle covers a narrow angle (approximately 90-110 degrees).

Many people think the coverage area of a PIR sensor is in the form of a complete circle but this is not true. If you have a top view of the area, you will see slivers of coverage separated by gaps of non-coverage. If you have a side view of the same area, you will see coverage as a conical shape. In either case, coverage is not in the form of a complete circle. 

3 classes of motion

There are three classes of motions that PIR sensors detect:

• major motion is when a person is moving at a walking speed of 1 metre per second
• minor motion is the motion of a limb moving such as waving or raising a hand
• micro motion is a person typing, flipping a page, or a movement on the mousepad

Once the coverage area and class of motion is identified, proper placement and setting the required sensitivity level of the sensor must be determined. 

In Part 2 of this series on PIR Sensors, we highlight best practices for configuring sensors for maximum efficiency and savings. We look at proper sensor placement and setting accurate sensitivity levels as well as how to reduce false triggers and sensor time-outs.

This article was first published by Osram as an online blog: http://info.osram.us/blog/pir-sensors-why-do-i-need-them

Changing Scene

  • Prev
Francis Chan, General Manager of Ultrasave Lighting, has announced his retirement from the company ...
The annual Lighting for Tomorrow competition was created in 2002 to recognize the best decorative, ...
Pioneer Lighting Inc.’s new interactive website features easily accessible updated spec ...
Standard’s photometric data files (IES files) have been updated and optimized and are now ...
The appearance of one of Europe’s most important cathedrals has been transformed with a new, ...
A special jury of industry experts has chosen the winners of the New Product Competition at MCEE ...
BizVibe has committed to creating a continuously improving platform for electrical and lighting ...
A Hamilton, Ontario retirement and long-term care residence recently received an $18,000 incentive ...
Power management company Eaton and its Cooper Lighting division have released of the 2014 SOURCE ...
Lind Equipment’s LE965LEDC, the latest in its Beacon Light line of LED floodlights, is a 30W ...

Design

  • Prev
The ongoing sea change between fluorescent and light-emitting diode (LED) lighting technologies ...
On Cartier Avenue in Quebec City, 34 giant lampshades backlit with LEDs and decorated with works by ...
The sturdy rectangular structure was built in the late 1470s as part of the Vatican’s fortified ...
The International Year of Light “is a global initiative that will highlight the importance of ...
It is no secret that lighting design plays a central part in the atmosphere of an interior ...
A lamp made with graphene, said by its U.K. developers to be the first commercially viable ...
Researchers from the Ecole Polytechnique Fédérale de Lausanne (EPFL) have used optogenetics to ...
A single backbone fibre ring of LuminexGigaCore Ethernet switches unifies and simplifies all the AV ...
The evolution of lighting technology is giving birth to amazing new possibilities. Where lighting ...
From May 3 to 7, New York City’s Javits Centre hosted the 26th edition ofLightfair ...

LED Technology

  • Prev
Mention LEDs in a conversation, and what first springs to mind is low energy use. But LEDs offer ...
LED's Part 2The benefits of LEDs almost seem too good to be true, and in some cases may be. Rapid ...
Helping LED Luminaire manufacturers develop products and gain market access is the intent behind ...
You may soon be able to add “growing space vegetables” to the list of uses for LEDs. Researchers at ...
Showing off your modern lighting advancements makes a powerful statement to customers. You’ll be ...
Acuity Brands, Inc. has launched a next-generation OLED product portfolio, including the ...
Halo light-emitting diode (LED) downlights from Eaton’s Cooper Lighting Division are featured in ...
LED keeps evolving. Six or seven years ago no one thought that LED was bright enough or ...
Although a relatively new technology, organic light-emitting diodes, OLEDs, are labelled today’s ...
Organic LEDs (OLEDs) are an interesting and promising new display technology. They provide a number ...

New Products

  • Prev
Eaton’s Lumark Caretaker light-emitting diode (LED) area luminaire is ideal for area and ...
Eaton’s new Neo-Ray Index light-emitting diode (LED) pendant luminaire from Cooper Lighting ...
Legrand’s Pass & Seymour Harmony Tru-Universal Dimmer comes with self-calibrating ...
iteline Corporation’s new 4” Versa-Series pot lights provide maximum safety and ...
Researchers at Duke University have developed a new method to make fluorescent molecules emit ...
The Fluke 1000FLT performs 5 essential tests in less than 30 seconds with one compact tool ...
Eaton’s Portfolio surface-mount light-emitting diode (LED) luminaire from its Cooper Lighting ...
Eaton’s Metalux Encounter and SkyRidge light-emitting diode (LED) luminaire families are now ...
Aimed at the residential market, Legrand’s new Pass & Seymour arc fault circuit ...

Latest News

IES

 

The American Medical Association (AMA) Council on Science and Public Health (CSAPH) has issued two reports related to nighttime lighting since 2012. The 2012 AMA Report CSAPH 4-A-12 report, Light Pollution: Adverse Effects of Nighttime Lighting, resulted in AMA Policy H-135.932, noting in particular the “need for further multidisciplinary research of occupational and environmental exposure to light-at-night”, the recognition of how interior lighting and the use of electronic media affect sleep disruption especially in children and adolescents, and the need for work environments operating in 24/7 fashion to have employee fatigue risk management plans in place. The IES supports the 2012 AMA Policy H-135.932. Read more: IES Report. . . 

 

Kerrwil Publications

538 Elizabeth Street, Midland,Ontario, Canada L4R2A3 +1 705 527 7666
©2018 All rights reserved

Use of this Site constitutes acceptance of our Privacy Policy (effective 1.1.2016)
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of Kerrwil