Ultra-Low-Power CO2 Sensors Enable Wireless Remote Monitoring for Building Management Solutions and IoT Connectivity
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Ultra-Low-Power CO2 Sensors Enable Wireless Remote Monitoring for Building Management Solutions and IoT Connectivity Gas Sensing Solutions Ltd. Page | 1 For regular updates, sign up at https://gassensing.co.uk Revision 2.0, 9 October, 2020 Copyright © 2021 Gas Sensing Solutions Ltd.

Gas Sensing Solutions Ltd. Page | 2 For regular updates, sign up at https://gassensing.co.uk Revision 2.0, 9 October, 2020 Copyright © 2021 Gas Sensing Solutions Ltd.

WHITE PAPER WHAT IS THE PROBLEM THAT NEEDS TO BE SOLVED? Building management systems (BMS), Demand-Controlled Ventilation (DCV) systems and Indoor Air Quality (IAQ) equipment often require installation of wirelessly-connected, battery-powered CO2 sensor devices in environments where mains power is not easily accessible or where its provision is not economically viable; such as with building technology upgrades and retrofitting. The requirement to measure air quality is being driven by two key factors, legislation, and economics. Many countries have either set or are in the process of...

WHITE PAPER HOW IS THIS ENABLED? A wireless CO2 sensor suitable for use in IAQ systems consists of four major building blocks, a CO2 sensor, microcontroller, low power radio module and a power source. Conventional CO2 sensors work by illuminating the gas using a filtered incandescent light source and measuring the absorption using a light detector. However, the power consumed using this type of CO2 sensor is too high to make it usable in a portable, or low power application. The cost of facilities management required to frequently change batteries is impractical and too expensive....

WHITE PAPER Gas Sensing Solutions’ CO2 sensor uses a solid state, ultra-low power LED light source. This type of light source has a number of advantages, particularly for low power applications. The CO2 gas is strongly absorbed by mid-IR 4.25um light. GSS manufactures its own LEDs, which have been specifically designed to emit a narrowband of light centred at 4.25um. This means little or no energy is consumed generating light of wavelengths that are unused. This is very different from a typical incandescent light source, which is intrinsically inefficient as it generates broadband light,...

WHITE PAPER INTRODUCING THE COZIR®-BLINK GSS has recently designed a new ultra-low power CO2 sensor module specifically for low power applications. The module consists of four major functions, a mid-IR LED, a photo-diode, an optical light path and a microcontroller. Light from the LED is injected into the optical cavity, which contains the CO2 gas that has been allowed to enter it through a hole on the top surface. The light that passes through the optical cavity is detected by the photo diode. The signal from the photo diode is digitised by the microcontroller and compared with a reference...

WHITE PAPER When the sensor is switched on, a measurement is automatically initiated. Data can be read out once the READY pin is pulsed high, approximately 3.3s after application of power. The sensor can then be subsequently switched off, saving power. The sensor interfaces to the host controller using a UART or I2C interface. In its simplest form, the sensor is accessed by the I2C Master requesting data from the sensor once the READY pin is pulsed high. The Master selects the CozIR®-Blink and reads out data in 2 bytes from the appropriate register. The data is in binary format. Switching...

WHITE PAPER Power consumption of the CozIR®-Blink module is defined by the following equation. ݑװݑװݑװݑװݑװݑװݑװݑװݑװݑ (ׂհݑްݑ) = ްݟϰݟ.ϰݟӰݟӰݟӰݟӰݟӰݟӰݟӰݟӢȗݒϰݒϰݒϰݒϰݒϰݒϰݒϰݒϰݒϰݒϰݒϰݒ ϰݒаݒаݒаݒ аݒѰݒѰݒѰݒѰݒѰݒ ѰݒѰݒ ѰݒѰݒѰݒѰݒ ѰݒѰݒѰݒѰݒѰݒѰݒ ѰݒӰݒӰݒӰݒӰݒӰݒӰݒӰݒӰݒӰݒ ӰݒӰݒ ӰݒӰݒ Ӱݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ԰ݑ ԰ݒѰݒѰݒѰݒѰݒѰݒѰݒѰݒѰݒѰݒѰݒѰݒ Ѱݒʰݒʰݒʰݒ ʰݑڰݑڰݑڰݑڰݑڰݑڰݑڰݑڰݑڰݑڰݑڰݑڰݑڰݑ In a typical application such as HVAC where the user might want to take a reading every minute, the power requirement can be as low as 417uW per reading for the CozIRς-Blink. Power consumption can be reduced even further by setting the...

WHITE PAPER IMPORTANT NOTICE Gas Sensing Solutions Ltd. (GSS) products and services are sold subject to GSS’s terms and conditions of sale, delivery and payment supplied at the time of order acknowledgement. GSS warrants performance of its products to the specifications in effect at the date of shipment. GSS reserves the right to make changes to its products and specifications or to discontinue any product or service without notice. Customers should therefore obtain the latest version of relevant information from GSS to verify that the information is current. Testing and other quality...