Ensuring the Reliability and Performance of Gas Measurement Equipment

Gas measurement equipment is a product of safe technology which is dedicated to the detection of dangerous gas concentrations, to trigger alarms when high levels of gas concentrations are detected and to activate counter measures before it becomes a dangerous situation that will compromise workers safety and that of assets and the environment. The safety of a work area is largely dependent upon the quality and reliability gas measurement equipment being used.

Ensuring the reliability of the gas measurement equipment

The reliability of the gas measurement equipment is not only based on its properties and performance but on installation, calibration and maintenance but more especially on the proper positioning of sensors. Naturally, sensors would be able to detect gas if it is within the range of the gas cloud. Improper positioning of the sensors makes the gas measurement equipment useless. Gas leaks can occur when cold liquefied and/or pressurized gases are released into the ambient air and get mixed with it. Gas dispersion and decrease in gas concentration relies upon the current temperature conditions and ambient air convection than on the density of pure gas. Having the sensors as close as possible to potential leak sources will provide the most reliable gas measurements. If such locations cannot be easily identified, sensors need to be distributed in the entire hazardous area since it is essential for the target gas to reach the sensors at operational conditions within a given time interval.

The importance of calibration for gas measurement equipment

Calibration is extremely important in order to gain reliable and accurate measurements. While zero calibration is rather simple because ambient air can be used for the purpose, calibration of sensitivity is not that easy. When electrochemical sensors are used to detect reactive gases, they have to be calibrated using the same reactive gases. However, such reactive gases also react with moist material surfaces and plastics. For safety reasons, it is important to use an easy to handle surrogate gas test for cross-calibration. If a variety of gases have to be detected and measured using only one sensor, the gas measurement equipment should be calibrated for the substance the sensor is least sensitive to. To achieve the best measuring performance, calibration should be performed under the exact conditions during operation.

Requirements for gas measurement equipment

Even if gas measurement equipment is a product of safe technology, it must comply with statutory requirements like electrical safety, explosion protection and electromagnetic compatibility including requirements for harsh environmental conditions for industrial applications. Design of gas measurement equipment should make sure that it will not act as a source of ignition. Test standards should ensure that the equipment will not produce wire bound or radiated disturbances and high frequency emissions. The equipment must be able to withstand electrical discharges without being affected in terms of reliability. A certain measuring performance must be met even under extreme environmental conditions that include temperature, pressure, wind speed, relative humidity, vibrations, etc. Hardware and software must also comply with certain requirements regarding the system’s reliability.