A new laser-based moisture analyzer, measuring trace moisture in process and speciality gases, has been introduced by SpectraSensors of California, a leading of optically orientated gas sensors for the industrial process and environmental monitoring markets.

In the past, speciality gas suppliers and users have relied on electrochemical cells, gravimetric and other technologies to measure trace amounts of moisture in speciality gases in process streams. Gravimetric technology has provided excellent results, but can also be seen as slow, expensive and demanding of a great deal of expertise to operate.

Now, however, a new H2O moisture analyzer is available that uses tunable laser diode (TDL) spectroscopy to provide highly accurate and virtually instantaneous measurements of trace amounts.

Based on advanced NASA optical technologies, the new product could play an important role in industry. For the users of high-purity bulk nitrogen, hydrogen, dry air or other speciality gases, it is critical to stable operations that these gases are free of contaminants such as moisture.
Although electrochemical devices may initially perform with acceptable accuracy, the confidence level in their measurements soon depreciates due to drift, the inability to read high concentrations of moisture.

The system consists of a cell that the sample gas flows through, a TDL that emit's a specific wavelength of light through the gas, an optical detector and software to analyse and deliver the results.

In effect, this new technology offers the best of both worlds in measurement as it affords accuracy and speed and does not become desensitised or the subject of drift over time.