Photoionization meters

Photoionization meter—more specific with increased sensitivity (on the order of a magnitude lower than the flame ionization meter). 

Knowing the ionization potential of a contaminant is required to determine the appropriate photoionization lamp for detecting that contaminant or family of contaminants in air. Photoionization instruments are equipped with a radiation sonrce (UV lamp), pump, ionization chamber, an amplifier (detector), and a recorder (either digital or meter). Generally, compounds with ionization potentials less than the radiation source (UV lamp rating) being used will readUy ionize and will be detected by the instrument. Conversely, compounds with ionization potentials more than the lamp rating will not ionize and will not be detected by the instrument. 

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