Spectral interference from background gas, which is common for tunable diode laser absorption spectroscopy-based moisture analysis for natural gas, can adversely affect detection specificity, sensitivity and accuracy. According to a new GE white paper, it has been demonstrated that by reducing sample gas pressure, the spectral interference can be greatly reduced and effectively removed in real time, and therefore, enhanced specificity, improved accuracy, lower detection limit, faster response and lower cost of ownership all become achievable.
In recent years, Tunable Diode Laser Absorption Spectroscopy (TDLAS) has gained popularity in the field of moisture measurement in natural gas for its fast response, and being non-contact and potentially drift free. More recently, it has expanded into the domain of trace moisture measurement in liquefied natural gas (LNG). It is not without challenges, however, to utilize TDLAS to accurately and reliably measure moisture in natural gas.