US Patent 9645112 Auto-cleaning and auto-zeroing system used with a photo-ionization detector

An auto-cleaning and auto-zeroing system (1) comprises a first conduit for flow of ambient gas (16) and a 2nd conduit (22) for flow of ambient air (18). A cleaning chamber (12) removes impurities from ambient air (18). The 1st conduit (20) and 2nd conduit (22) are connected to a valve, operated by the continuous motor, which continuously draws ambient gas (16) or cleaned and filtered ambient air (18) through the system. Cleaned and filtered ambient air (18) enters the ionization chamber (10) to carry out a cleaning (flushing) and a cleaning (ionization) cycle. In this manner, contaminants and pollutants left in the ionization chamber (10) from the measurement of ambient gas (16) are flushed out and removed.