Sensors are placed at all air inlets and outlets, continually sending air samples to the CO detection control cabinet where they are treated and filtered. The differential between the sum of inlet samples is compared with the sum of outlet samples. When the CO differential reaches one of three programmable levels, the appropriate alarm is signaled:
By this means, a potential explosion or fire risk is averted in the very early stages. Continuous calibration is done by checking the process reference gas against a sample gas to improve accuracy. Differential CO removes the influence of external CO variations!