Recorded at AIHce EXP 2021
Confined space instruments are often equipped with photoionization (PID), electrochemical (EC), and LEL sensors to measure the gases and vapors present in the space. In the past, nearly all LEL sensors were catalytic combustion (CC) type. Manufacturers have added new sensors: miniaturized and full-size infrared (IR) and molecular property spectrometer (MPS) sensors. The new sensors are based on different detection principles, and have significantly different capabilities and limitations than CC LEL. It is critical to match the capabilities of the sensor with the application, and the gases and conditions that are potentially present. Using a sensor that is not appropriate for the application can lead to inaccurate readings or in the worst case, complete inability to detect the gases and vapors of interest. This presentation will review the types of combustible gas and vapor sensors available for use in multisensor CS instruments, discuss the capabilities and limitations, and how to select the best sensor based on the space conditions and the gases that need to be measured.
Upon completion of the session, the participant will be able to:
- Explain the capabilities and limitations of real-time LEL sensors.
- Determine the ability of specific sensors to detect the gases of interest.
- Describe the effects of O2, interfering gases, temperature and humidity on sensor performance.
- Identify and avoid common LEL monitoring mistakes.
- Select the LEL sensor based on conditions and the gases present.
- Enhance the accuracy of LEL monitoring results.
Mr. Robert Henderson, MBA