What is Calibration Gas?
Gas calibration is the first step to ensuring your life saving device is working properly. It checks that the sensors are reacting to gas exposure. This is known as “span gases.”
Humans can be exposed to certain gases for only so long before the results turn deadly. Calibration checks that the sensors work and that the levels they are detecting are correct. Calibration is the most important step to ensure safety.
Span gases are specific mixtures used to calibrate analytical instruments such as gas detectors and gas analyzers; these could be either single gas or multi-gas mixture. This type of equipment requires regular calibration or bump testing to ensure proper functionality.
What are Flow Rates?
Depending on the gas detection monitor or analyzer, the flow rate of the span gas is determined by the regulator used (some examples: 0.5LPM/1.0LPM etc.) and then there is a 70 series (male threaded regulator), 71 series (female thread regulator). This information can be found in the user manual in the calibration section.
To simplify the calibration process, you can use a demand flow regulator. A demand flow regulator will automatically adjust the flow of calibration gas to the instrument, based on manufacturer specifications. A demand flow regulator helps with calibration accuracy and can save on calibration gas.
What happens during Calibration?
Calibrating a gas detector is the action of setting the monitor to “match” the value of a known gas concentration. The gases used during calibration must be mixed and certified by NIST standards to ensure proper, safe, and accurate readings of the gas detector.
After a calibration, the monitor will go into audible and visual alarm when the gas measured meets or exceeds the alarm values that have been pre-set.
What happens during a Bump Test?
Bump testing an instrument exposes the sensor to the known gas to see if the sensor reacts. This is the only way to test that all the monitors and sensors are working.
A monitor will either give a visual, vibrating or audible alarm when the sensor(s) exceed the allowable level. Calibrating the device ensures the monitor will react when needed and alert your worker that danger is in the air.
Important notes about calibration gas cylinders:
There are a few important checks to make before using calibration gas:
- The expiry date. Most gases have a shelf life of 3 years however, in some cases they can be between 6-12 months. This can be verified on the cylinder or in the calibration gas certificate for each cylinder.
- Check that labels are accurate and the gas concentrations in the cylinders are accurate according to the +\- on the calibration certificate.
- Safely disposing empty cylinders. To protect the handler and the environment, it’s critical that disposal follows the strict laws and regulations in your area. If you have any doubts or questions, contact your supplier.
Don’t take risks with safety. Perform regular calibration and bump tests.
Gas detection instruments are life saving devices. Without fail, this equipment must undergo 30 day full calibration and a daily bump test.
- Some sensors can be sensitive to airborne pollutants, like aerosol spray, or even dust. The smallest contamination can poison the sensor. The only way to be sure the sensors are working properly is to perform a bump test or calibration.
- Different hazardous work environments could involve either single toxic gas or multiple gases that could be in the air at one time, it's important to test all sensors to make sure all the sensors react.
It’s not worth the risk to skip calibration.