Model 20/20B detects ammonia, halocarbons, CO2, hydrogen, propane and carbon monoxide. With solid-state technology, the unit detects ammonia in the range of 0 to 300 ppm and halocarbons in the range of 0 to 1,000 ppm. Typical alarm points are 150 and 300 ppm. The detector has an expected life of 10 years and a calibration frequency of 6 months to 1 year.
Parker Hannifin Corp., Refrigerating Specialties