GSS Ltd, the LED-based NDIR detector specialists, continues to push the boundaries for CO2 detectors with the launch of its new SprintIR6S. GSS’ unique SmartIR™ technology has enabled it to create a sensor that can take up to 20 readings per second, which is a world record for NDIR CO2 detectors, and has a six times faster response rate than the current SprintIR*.
We are the only company producing CO2 sensors using LEDs and photodiodes and, as we make the LEDs and photodiodes ourselves, we have been able to develop ultra-fast response times that no other NDIR sensor can match. Typical NDIR CO2 detectors take several seconds or even minutes to take a reading – because they use slow-reacting IR sources, which need time and energy to warm up, like MEMS hotplates, micro-bulbs or filament-based micro-lamp technologies. Our LEDs, by contrast, are Solid State emitters, and illuminate almost instantly. With the new SprintIR6S, we’ve also minimised the sample volume down to only 2ml, which enables us to achieve our fastest ever response rates*. This puts us in a unique position to open whole new application areas for CO2 monitors that could never be addressed by slow responding sensors based on traditional IR sources.
Ralph Weir, CEO, GSS
Applications for this new class of ultra fast CO2 sensors include health where they can capture rapidly changing CO2 concentrations in the breathing cycle to provide diagnostic information, which can be used in fitness testing, breath analysis/measurement, capnography, sports science and veterinary to name a few. In Industrial Health and Safety applications, such as factories where CO2 is used for modified atmospheres to delay packaged food from spoiling, they can provide ultra fast detection of rising CO2 levels. Even a doubling or tripling of normal CO2 levels can affect concentration and productivity with higher levels having increasingly deleterious effects on health right up to unconsciousness and death.
A leak from a CO2 canister or similar can push CO2 levels up from the normal 400ppm to several thousand ppm in seconds. You cannot smell CO2 and it is colourless. Yet it can present serious health problems at raised concentrations so, the sooner an alarm is raised, the sooner people can take remedial action. For example, restaurants and pubs usually have CO2 cylinders in the basement for the drinks but basements typically have poor ventilation so an undetected CO2 leak could suddenly raise the CO2 level when someone was in the basement and render them unconscious – or dead. Our new sensors can give the earliest possible warning.
Ralph Weir, CEO, GSS
GSS’ multi-patented SmartIR™ technology detects the presence of CO2 by detecting how much light is absorbed by CO2 molecules as light passes through the sample gases – called Non-Dispersive InfraRed (NDIR) absorption. CO2 absorbs between 4.2 and 4.4 microns so that its presence is easily detected, and the amount of light absorbed indicates how much CO2 is present.
Typically, CO2 detectors use a miniature heater (such as MEMS devices like micro hotplates, microlamp/microbulb or filament heater) to generate a range of wavelengths that have to be filtered down to the wavelengths needed, which is wasteful and energy inefficient, especially as a lot of heat is produced. By contrast, GSS developed the world’s first commercial, mid-range IR LEDs that are specifically tuned to emit just at 4.2 to 4.4 microns, making them highly energy efficient. As a result, GSS CO2 sensors are the only NDIR CO2 sensors that can be powered by batteries – a single lithium cell can power a SmartIR sensor for up to ten years.
At less than a cubic inch (23.8mm in diameter and 24mm tall), the SprintIR6S operates at between 3.25 and 5.5V, with a power consumption of only 35mW. The SprintIR6S is available in measurement ranges from 0% to 100%.
*Based on 0.1 litres per minute flow rate and 0-10% step change in CO2 concentration.