The Critical Role of Toxic Gas Monitors in Protecting Workers and Facilities — Occupational Health & Safety
The Critical Role of Toxic Gas Monitors in Protecting Workers and Facilities
Electrochemical gas sensors are vital in detecting harmful gases and require regular maintenance to ensure safety and operational efficiency.
Toxic and combustible gas monitors are essential safety devices that ensure safety in commercial or industrial operations. These devices detect the presence of harmful and flammable gases in a specific area and notify when the concentrations reach dangerous levels.
The primary component used in the gas detection device for sensing is the sensor. The function of the sensor is to detect the gases and convert them into electrical signals (typically, the higher the concentration levels in an area, the higher the electrical signals). The signals are then relayed to the primary device, and the device in turn uses multitudes of subsequent systems to notify the users (e.g., through sounding an alarm, sending a digital text or e-mail notification).
Based on these working principles, there are various types of sensors available in the marketplace. The most common used in the industry are electrochemical sensors, catalytic sensors, infrared sensors and photoionization sensors. Let’s briefly discuss the most commonly used electrochemical sensor, their working principles, and recommended maintenance guidelines to ensure the safety of the people, the property and the bottom line.
Electrochemical Sensors
Electrochemical gas sensors measure the concentration of a target gas by oxidizing or reducing the target gas at an electrode and measuring the resulting current. A basic electrochemical cell typically contains three main components. First, there are two electrodes, one anode and one cathode. The anode is the point where the current enters the electrode, and the cathode is the point where the current leaves the electrode. Second, there is an electrolyte, which facilitates the cell reaction and carries the ionic charge across the electrodes. Finally, a gas permeable membrane covers the sensing electrode and is used to control the amount of gas molecules reaching the electrode, while also filtering unwanted particulates.
An industrial electrochemical sensor usually contains 3 electrodes (sometimes even 4)—a reference electrode in addition to the anode and the cathode—in contact with the electrolyte. As the name suggests, this electrode provides the reference for the potential measurements.
Electrochemical Sensors – Working Principle
Depending on the applications, electrochemical sensors detect and measure various gases, including O2 (Oxygen), CO (Carbon Monoxide), NO2 (Nitrogen Dioxide) and SO2 (Sulphur Dioxide).
