All natural gas contains moisture that must be monitored throughout production, storage, transportation, and distribution. Accurate H₂O measurement helps operators meet gas quality specifications, prevent pipeline corrosion, and avoid costly shipment delays caused by false wet-gas readings. Traditional moisture measurement technologies can be affected by contaminants such as glycol, methanol, compressor oil, and sulfur compounds. Tunable diode laser absorption spectroscopy (TDLAS) provides fast, accurate, and low-maintenance moisture measurements without these interference effects.
The benefits: Fast, interference-free moisture measurement
10-20 sec
typical T90 response time
ASTM D7904
standard test method compliance
Natural gas producers, transporters, and distributors require reliable moisture measurements to maintain gas quality and protect infrastructure. TDLAS technology provides accurate, real-time H₂O monitoring while eliminating many limitations associated with traditional moisture measurement methods. Benefits include:
Virtually maintenance-free operation
No interference from glycol, methanol, or amines
Accurate, real-time moisture measurements
No wet-up or dry-down delays
Reliable operation in harsh environments
Short payback with no consumables
NIST-traceable calibration
Analog and serial outputs for remote monitoring
Analyzer management software included
Compliance with ASTM D7904 moisture measurement methodology
The challenge: Measuring moisture in contaminated gas streams
Moisture measurement is critical for ensuring natural gas quality and preventing corrosion in pipelines and equipment. False-positive moisture readings can be extremely costly because gas deliveries may be rejected if the gas is believed to be wet. Natural gas streams frequently contain contaminants such as glycol, methanol, compressor oil, sulfur compounds, and other liquids or solids that can damage sensors or create cross-interference effects.
Traditional chilled mirror analyzers and contact-based electronic moisture sensors can struggle in these conditions. Chilled mirrors are inherently slow and can be influenced by the condensation of other compounds on the mirror surface. Contact sensors are exposed directly to the process stream and may experience errors, interference effects, degradation, or premature failure when exposed to contaminants. These limitations increase operating costs and reduce confidence in the measurement.
Our solution: Proven TDLAS moisture monitoring
Endress+Hauser uses TDLAS, a technology that has been deployed in thousands of natural gas installations worldwide. Because the measurement is laser based, it is not adversely affected by glycol, methanol, amines, H₂S, moisture slugs, or other common natural gas contaminants that challenge conventional technologies.
The rugged design enables reliable operation in natural gas production facilities, gathering systems, pipelines, storage facilities, compression stations, and custody transfer applications. Operators benefit from fast response times, accurate real-time measurements, and minimal maintenance requirements.
Unlike many traditional technologies, Endress+Hauser analyzers do not require routine field calibration. Validation can be easily performed using binary gas blends containing H₂O, supporting long-term measurement confidence while reducing maintenance effort.
Various product models with differing features are available for this application. Certain product measurement combinations are calibrated in a nitrogen background instead of methane. Contact Endress+Hauser prior to sourcing validation material.
Process stream composition may need to be specified for assessment, calibration, and measurement performance, including the normal or typical composition and expected variation for each component. Deviations from the typical composition table will be reviewed by Endress+Hauser for suitability.
The chart above depicts the output of a Endress+Hauser TDLAS gas analyzer to a large “slug” of moisture in a natural gas stream. Note the rapid response at the beginning of the event (“wet-up”), and at the end (“dry-down”).
Conclusion
Accurate moisture monitoring is a critical component of safe, efficient, and profitable natural gas operations. By combining proven TDLAS technology with a low-maintenance design, Endress+Hauser delivers reliable H₂O measurements even in demanding conditions. The result is greater confidence in gas quality, reduced maintenance effort, faster response to changing conditions, and long-term protection of assets across production, storage, transportation, and distribution networks.
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