MVR-300™ Refrigerant Gas Detector
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P/N: 6203-9000 Version 1
SECTION 6.
SENSOR PRINCIPLE
Semiconductor or metallic oxide sensors (MOSs) are among the most versatile of all broad-range
sensors. They are heated to a temperature between 150º and 300º C depending on the gas(es) to be
detected. The temperature of operation as well as the “recipe” of mixed oxides determines the sensor
selectivity to various refrigerants. Electrical conductivity greatly increases as soon as a diffusion process
allows the refrigerant molecules to come in contact with the sensor surface. Water vapor, high ambient
humidity, temperature fluctuations, alcohols, cleaning agents, sprays, polishes, detergents, and low
oxygen levels can result in higher readings.
NOTICE
Certain substances in the environment may impair the sensitivity of the sensors:
1. Materials containing silicone or silicone rubber/putty
2. Corrosive gases such as hydrogen sulfide, sulfur oxide, chlorine, hydrogen
chloride, etc.
3. Alkaline metals, salt water spray.
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