Hydrogen Sulfide (H2S) is a toxic gas that is often generated in confined spaces, such as manure pits or sulfur hot springs. It is a colorless gas with a pungent rotten egg smell and can quickly kill people who breath in high levels of it. Because of its deadly properties, it is important to have the right equipment to detect H2S and stay safe on the job.

Personal gas H2S monitor that use electrochemical sensors are designed to alert workers when the concentration of hydrogen sulfide exceeds a safety level. They operate by exposing a sensor to a sample of the target gas and measuring the interaction of the sensor with it. The monitor then produces a signal proportional to the concentration of hydrogen sulfide.

When the H2S sensor on a gas detector comes into contact with a sample of hydrogen sulfide, it dissociates into charged ions that change the resistance of the sensor. This changes the sensitivity of the sensor, and the monitor responds with an electrical signal. Most monitors that work on this principle have a fast response time and are able to respond to low concentrations of H2S.

Understanding H2S Monitors: Safety Solutions for Hazardous Environments

The reliability of these H2S monitors is dependent on the calibration and bump testing process that is followed. For example, it is common practice to test the monitors on a regular basis using a bottle of calibration gas that contains known concentrations of H2S. The gas is then attached to the monitor using a length of tubing or special clip, and the sensor is exposed to the gas. Ideally, the monitor should alarm within a minute or so to demonstrate that it is functioning properly. If it does not, the monitor must be calibrated and bump tested again before workers are allowed into a hazardous area.