1. PID Gas Meter/Detector

2. Introduction Air monitoring data is useful for: *Assessing the health risks to the public and response workers. *Selecting personal protective equipment. *Delineating areas where protection is needed. *Determining actual or potential effects on the environment. *Selecting actions to mitigate the hazards safely and effectively.

3. Toxic Atmosphere Monitors Toxic atmosphere monitoring is done to: *identify airborne concentrations that could pose a toxic risk to response workers and the public. *evaluate the need for and type of personal protective equipment. *set up work zones or areas where contaminants are or are not present.

4. PID Gas Meter/Detector To be useful air monitoring instruments must be: *Portable and rugged. *Easy to operate. *Easy to operate. *Inherently safe. *Inherently safe. *Able to generate reliable and useful results. *Able to generate reliable and useful results.

5. PID Gas Meter/Detector The response time, sensitivity, selectivity, accuracy and precision of an instrument are important in evaluating the reliability and usefulness of the data the instrument generates. The response time, sensitivity, selectivity, accuracy and precision of an instrument are important in evaluating the reliability and usefulness of the data the instrument generates.

6. PID Gas Meter/Detector Limitations & Considerations Ionization Potential(IP) Ionization Potential(IP)  Amount of energy required to displace an electron  Each chemical has unique IP  PID must have IP greater than or equal to material desired to detect for accurate measurement  Typical lamp is 11.7eV

7. PID Gas Meter/Detector Useful to detect Useful to detect  Most organic compounds  Well suited to aromatic compounds

8. PID Gas Meter/Detector Well suited for Well suited for  Area monitoring  Leak detection  Qualitative measurements  Establishing perimeters of contamination  Air, water, soil screening

9. PID Gas Meter/Detector Method of operation Method of operation  Creates ions by exposing test gas to UV light.  Measures conductivity of the gases in the UV light field.

10. PID Gas Meter/Detector Calibration Calibration  Calibrated with calibration gas and internal adjustment  Reading on meter is therefore in reference to calibration gas, not actual field concentration  Record actual results as ppm-calibrant gas

11. References Cited NIOSH Manual of Analytical Methods (NMAM®), 4th ed. DHHS (NIOSH) Publication 94-113 (August, 1994), Cassinelli, M.E. & O'Connor, P.F. (pfo1@cdc.gov), Eds. O'Connor, P.F. (pfo1@cdc.gov)O'Connor, P.F. (pfo1@cdc.gov)

12. Bibliography DiNardi Salvatore R. (1998) The Occupational Environment-Its Evaluation and Control, AIHA, Fairfax, Virginia DiNardi Salvatore R. (1998) The Occupational Environment-Its Evaluation and Control, AIHA, Fairfax, Virginia Goetsch David L. (1999) Occupational Safety and Health for Technologists, Engineers, and Managers, Prentice Hall, Upper Saddle River, New Jersey Goetsch David L. (1999) Occupational Safety and Health for Technologists, Engineers, and Managers, Prentice Hall, Upper Saddle River, New Jersey