PDC 112

Theory and Application of the 4 Gas/PID Sensor Technologies



intermediate | Credits: 8 CM Credit Hours / 0.8 CEU / 0.5 CMP
Saturday, May 21 | 8:00 AM – 5:00 PM
Limit: 45


Real-Time Detection Systems, Sensor Technologies


This PDC provides an advanced knowledge of the use and limitations of the 4-Gas/PID portable gas-detection instrumentation. This PDC is designed to enhance the working knowledge of current users of the most popular real-time gas-detection instrument, 4-Gas or Multi-Gas meter. This PDC discusses the technology that resides under the cover of the instrument. The belief is that if the user has a better understanding of how the instrument works including its limitations, the application of this instrument in the field and in emergency situations will greatly improve. This PDC is perfect for industrial hygienists who want to further their knowledge in the applications and limitations of direct-read instrumentation as well as for first responders who rely on this technology to make decisions in emergency situations.


Participants should have a general working knowledge of 4-Gas technology and should have experience using multi-gas direct read gas detection instrumentation as well as experience calibrating it.

Learning Aids

Participants must bring a laptop OR tablet/iPad.


Upon completion, participants will be able to:

  • Recognize sensor poisons.
  • Distinguish cross sensitivities.
  • Show how the O2 sensor can also be used as a broad band detector.
  • Explain the difference between calibrating to methane vs. calibrating to pentane.
  • Develop a conceptual understanding of how each of the sensors work.


  • Instrument Overview
  • Review of Basic Chemical Principles
  • Oxygen Sensors
  • Combustible Gas Sensors
  • Electrochemical Sensors
  • Review of Sensor Poisons
  • Photoionization Detector
  • Calibration Data Logging
  • Guidelines for Selection

Transfer of Knowledge

Instructors will evaluate participants understanding of the materials presented based on:

  • Practice exercises
  • Group activities
  • Interactive games

Course Survey: https://www.surveymonkey.com/r/16PDC112 

Sponsoring Committee

Real-Time Detection Systems