All Pyreos products use its unique thin-film PZT pyroelectric technology, whose low thermal mass increases the sensors’ speed of response, enabling high measurement rates, high SNR and lower-power systems. Operating in current mode, the dual and quad sensors offer a responsivity of about 200,000 V/W, and have a fast, stable response over a wide operating frequency range and a long operating lifetime. The sensing elements form part of a low-noise internal circuit that includes a CMOS op-amp and a 10 GΩ feedback resistor which produces voltage output signal. In the dual channel device, the output voltage is centred on half the supply voltage, allowing single power supply operation and reducing the need for external gain stages that could introduce noise.
Packaged in the TO-39 can, with a filtered window over each of the two or four sensing elements, the dual-sensor parts are available in over 20 variants, using different combinations of filters to tune them to detect gases including methane, carbon monoxide, various forms of carbon dioxide, anaesthesia gases, nitrous oxide, freon, ethylene, and more. There are also variants tuned to detect specific aspects of food processing, such as the presence of sugars (e.g. lactose), ethanol, protein and fat. The quad-sensor parts use the additional two sensors and filters to increase the specificity of their detection. Variants are available for exhaust gases, and anaesthesia.
The dual sensors work at operating voltages between 2.7V and 8V, while the quad sensors need a supply of between 2.7V and 5V. The operating temperature range for both types is –40 to +85°C.
Pyreos Ltd – www.pyreos.com