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
The Lighting Research Center (LRC) recently released its latest publication, Lighting Answers: UV ...
TPL Lighting, a full service supplier of architectural lighting and controls for the Greater ...
The LIT Lighting Design Awards was created to recognize the efforts of talented international ...
From designers of custom and modular systems to cultivators and processors, the need for certified, ...
Signify Canada will now refer to a select collection of Signify North America luminaire brands as ...
The Northern Lighting Awards recognises exemplary lighting and controls as designed and integrated ...
The International Association of Lighting Designers (IALD) has announced the ...
Signify Canada has added Jean-Francois Ouellet as Eastern Zone Sales Leader for Signify Canada ...
A new edition of UL 8802, the Outline of Investigation for Germicidal Systems, titled UV ...
The DesignLights Consortium (DLC) today issued a Request for Proposals (RFP) seeking consultant ...

Changing Scene

IESThe IES knows you want to take your knowledge with you. In this special webinar, IES staff will guide you through The Lighting Library® – a giant step forward in how we create and deliver standards. This new online subscription-based platform allows access to our full set of standards from anywhere with an internet connection, updates automatically, and allows for more regular revisions of the standards to keep up with the times. 

This webinar will provide details of how the Lighting Library is organized and how to best utilize the platform as a tool for your lighting business.  
Read More


 

Design

  • Prev
Ottawa’s River Dental location, adjacent to the Rideau River and Rideau Canal, inspired an office ...
When it comes to establishing a trend and setting a mood, Fiona Rimmer, Interior Designer ...
The light installation Het Licht van Jan (Jan's light) was unveiled today in an ...
A leading urban trend is the creation of signature dynamic lighting designs for iconic downtown ...
In Part 1 of this interview with Leora Radetsky, we covered smart lighting, ...
For years, officials in Calgary, Alberta have been concerned with improving the perceived sense of ...
In a recent article on LEDs, we covered numerous topics and questions to help consumers buy ...
When the Government of Canada contemplated developing a co-working concept, they chose Orleans, a ...
Building a control system for a modern lighting installation can seem like an impossibly complex ...
The design of outdoor architectural fixtures requires the consideration of multiple environmental ...

LED Technology

  • Prev
The Alberta Electrical Association (AEA) held their first virtual Learning Expo this past week, ...
Some of the recent blog posts have described different components in Networked Lighting Control ...
The Northwest Energy Efficiency Alliance (NEEA) recently published a study seeking to compare ...
Consumer UVC germicidal devices are entering the market rapidly because of an increased demand for ...
Scientists at the Circadian Light Research Center have identified the narrow band of blue light ...
Pierre Longtin, President of Nyx Hemera, was proud to announce the installation of TLACS-A, ...

New Products

  • Prev
The new WSXA Series offers all the benefits of the WSX Series but with improved functionality and ...
The new AimLite LED backlit panel lights P14BR series utilize next-generation backlit technology, ...
SKYE is a high-performance, easy to install residential grade downlight solution that offers good ...
The eLumigen High CRI C1D2 LED Fixture is the ideal light source replacement for Paint Booth, ...
The eLumigen LED Linear Vapor Tight fixtures are designed for installation at mounting heights of ...
Liteline Corporation's 4¼" aluminum remodel housing is now available in black in addition to ...
Aculux 2" LED Precision Luminaires With the diminutive 2"Aculux LED precision luminaire, you can ...
Enjoy faster, simpler installation with preconfigured wireless occupancy sensor kits, resulting in ...
Philips Hue Phoenix from Royal Philips is the first in a new range of white ambience connected ...
Eaton has helped improve the lighting performance and energy efficiency in a campus recreation ...
Kerrwil Publications Great Place to Work. Certified December 2019 - December 2020

538 Elizabeth Street, Midland,Ontario, Canada L4R2A3 +1 705 527 7666
©2021 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