Michell Instruments has introduced a method to verify the accuracy of the OptiPEAK TDL600 moisture in natural gas analysers in the field by using certified cylinders of moisture in nitrogen, rather than a methane calibration gas.
The TDL600 can analyse moisture content within 1 per cent of reading. According to Mitchell Instruments, while this accuracy is beneficial to ensuring the quality of natural gas, it means that any verification needs a cylinder of certified moisture content. And because TDLAS analysers are configured for a defined background gas type, in this case natural gas, the cylinder gas required is moisture in methane. However, cylinders of methane are not always easily available in all regions and shipping a flammable high-pressure gas cylinder between countries is problematic.
Therefore, the company has developed a solution into the functionality of the TDL600 analyser. If no certified moisture in methane calibration gas is available, the user can select a second spectroscopy profile in the analyser for nitrogen background gas. The verification is then carried out using a cylinder of certified moisture in nitrogen. These are readily available around the world and are far easier and safer to ship between countries.