Prime3 

Voltage output Infrared Gas Sensor for Carbon Dioxide

Features

·  High Resolution of 0.01% vol for 0-6% vol and 0.1%vol for 6 – 100% vol

·  Operates independent of supply polarity

·  Voltage or pellistor mimic bridge output

·  Operating voltage range 3.0V – 5.0V

·  Operating current 80mA typical

·  Latest technology MEMS detectors

·  Sensing ranges: 0-10% volume CO2 up to 0-100%volume CO2

·  All metal construction with isolated housing

·  Small internal volume

·  Flexible electronic configuration access

·  User calibration also enabled by hardware connections

·  Wide operating temperature range

·  Fast response

Description and Operation

The Prime3 sensor use the non-dispersive infrared method to detect the presence of carbon dioxide. The sensor contains an infrared radiation source, a dual element infrared detector, a unique optical waveguide into which gas diffuses and integrated ARM7 core microprocessor based electronics to provide a voltage output which is independent of the power supply polarity. The sensor can be configured to provide a linear voltage output, typically 0.4V – 2.0V over range with respect to the negative supply pin, or a pellistor format output, typically mid supply at zero with the voltage output increasing with respect to the detector pin by 100mV at range. In addition, the output can be read and the internal configuration can be accessed by a serial communications link. The communication link contacts are pads in the 3 pin version Prime3 and pins in the 5 pin version Prime3. The internal electronics perform all the functions of driving the optical parts of the sensor, extracting the detector signals, converting the signals to a concentration, applying temperature compensation and scaling the output. When in a pellistor configuration, the Prime3 can operate in existing pellistor circuitry subject to the power supply requirements. External components will be required to meet the power supply requirement when a Prime3 is used in constant current pellistor circuitry. The Prime3 is not currently Ex approved so should be housed in a suitable Ex enclosure when used in Hazardous areas.

Technical support on implementation and application notes are available from Clairair Limited.