Moisture analysis – Choose an online hygrometer moisture analyzer

How to choose the right process moisture analyzer for your application? When selecting a gas analyzer for moisture analysis, you may not be sure which one is the best for your requirements or process. Choosing the right moisture analyzer for your specific application goes beyond specifications which don’t show the complete picture. Moisture measurement performance for your process sample or what is necessary for uninterrupted all year operation are just some examples of criteria which can’t be found on the datasheet. Therefore, it’s crucial to understand the functionality and performance of the instrument from a complete process view.

In this article

Keep your process dry of moisture and your analyzers healthy

Moisture in short

Moisture in process gas is a contaminant that reduces the thermal conductivity and increases the viscosity of the gas. The presence of moisture indicates that either the system was not purged adequately after the last maintenance cycle or that there is an ambient leak, which can be a very damaging and hazardous condition.

Overview of our moisture analysis products

303B Process Moisture Analyzer Series

Highly accurate portable measurement of trace moisture in gas streams for Division 2 areas

3050 Process Moisture Analyzer Series

Accurate and reliable measurements for mole sieve dryer regeneration

5000 Process Moisture Analyzer Series

Fast, reliable ppmv moisture measurement

Predictive maintenance & service

Professional rapid-response service

38M Particulate Coalescing Filter

The Liquid Block™ will completely valve off flow through the membrane to prevent liquid break-through

2850 Process Moisture Analyzer Series

Highly accurate portable Ultra fast response speed, exceptional accuracy, virtually no interferences, multi-gas compatibility, and on-board measurement verification

5812 Process Moisture Analyzer Series

Reliable moisture in natural gas measurement

5820 Process Moisture Analyzer Series

Ideal for critical low-level moisture measurement applications

5830 Process Moisture Analyzer Series

Ideal for critical moisture measurement applications

5920 Process Moisture Analyzer Series

The Liquid Block™ will Low parts per billion (ppb) gas analysis – ideal for critical moisture measurement applications

Types of moisture analyzers

Quartz Crystal Microbalance (QCM) analysis


Quartz Crystal Microbalance (QCM) for moisture analysis employs a quartz crystal whose oscillation frequency changes in response to mass variations on its surface. When exposed to a gas sample, moisture adsorbs onto the crystal, altering its mass and consequently its oscillation frequency. This frequency shift is directly proportional to the moisture content, allowing for precise and sensitive moisture measurements. QCM is valued for its sensitivity and response.

Chilled mirror analysis

Chilled mirror technology for moisture analysis involves cooling a mirror to a temperature where moisture from a gas sample condenses on its surface. This dew point temperature is precisely measured, providing an accurate indication of the moisture content in the sample. This method is suitable for various applications that require precise humidity control and measurement.

Silicon Oxide sensor technology

Silicon Oxide sensor technology for moisture analysis utilizes a sensitive layer of silicon oxide to detect water vapor. When water molecules interact with the silicon oxide surface, they cause a measurable change in the sensor’s electrical properties, such as capacitance or resistance. This change is directly correlated to the amount of moisture present, providing accurate and reliable moisture analysis in various applications, from industrial processes to environmental monitoring. This technology is prized for its sensitivity, stability, and rapid response to changes in moisture levels, making it suitable for a wide range of applications where accurate moisture detection is critical.

Range of moisture measurement applications

Transmission Pipelines

Gas is transported from the processing plant to underground storage sites, industrial users and city gate metering stations via a large network of pipelines. As the gas travels along the pipeline, it passes through metering points where it is sold from one party to another – this is the custody transfer point. Understanding the gas quality at custody transfer points is essential.

Dehydration

The dehydration process removes water vapor in natural gas. Several different methodologies are used to accomplish this, including compression, phase separation, absorption and adsorption. Tri-ethylene glycol contactors and molecular sieve dryers are two of the more common dehydration methods for gases. Moisture measurement is critical to optimize the drying process and ensure that the gas is dried to the required specification. Analysis is typically performed at the outlet of the drying process.

Sweetening

Sweetening is the process whereby hydrogen sulfide (H2S) and carbon dioxide (CO2) are removed from the natural gas. Both H2S and CO2 promote corrosion through the formation of acids in the presence of water and can cause stress cracking in the pipelines. 

Landfill Gas

Landfill gas is generated from the decomposition process of organic materials contained in a landfill. Similar to conventional natural gas, landfill gas can be transmitted in a pipeline network for use in transportation, power generation, or at industrial end users. Unlike conventional natural gas, landfill gas typically contains a lower concentration of methane and higher concentrations of impurities, such as carbon dioxide (CO2). Landfill gas must be treated to remove unwanted impurities, such as CO2, hydrogen sulfide (H2S), or water vapor (H2O), prior to injection into a pipeline or transmission to an end use.

Underground storage

Just like transmission measurements, impurities in the captured CO2 need to be measured.  Although levels of H2S, methane, and carbon monoxide are not likely to significantly change during storage, moisture levels can. Pipeline managers need to understand any changes in the moisture levels in order to properly manage it.

Gas purification

Most industrial gases are produced to meet a specified purity. This requires accurate monitoring of any contaminants such as moisture, carbon dioxide, carbon monoxide, hydrogen, oxygen, or hydrocarbons, during the production process to ensure the necessary quality is met. Industrial gas suppliers demand accuracy to certify product quality. Fast, precise and reliable analysis of the gas is carried out to ensure impurities remain within specified, very low limits.

Hydrogen recycle gas

Proper moisture balance in feedstocks and hydrogen recycle streams must be maintained to optimize product yield and catalyst life. Accurate and rapid results are required despite wide variations in moisture content.

Quality

The aim of gas purification is to ensure the required level of product quality. Monitoring the trace contamination from moisture and other compounds using a range of technologies helps determine the final quality.

Process Moisture Analyzers for LCD, OLED, and QLED display monitor manufacturing
Process moisture analyzers are used for LCD, OLED, and QLED display manufacturing

Process moisture analyzers

303B Process Analyzer Series

Based on Faraday’s Laws of Electrolysis, the 303B Process Moisture Analyzer Series absorbs and electrolyzes moisture down to fractional parts per million (ppm) and is linear to its 2000 parts per million by volume (ppmv) maximum reading.
303B Process Moisture Analyzer Series

Based on Faraday’s Laws of Electrolysis, the 303B absorbs and electrolyzes moisture down to fractional parts per million (ppm) and is linear to its 2000 parts per million by volume (ppmv) maximum reading. An electrolytic cell does not require calibration and is virtually specific to water, so it can be used to monitor the moisture content in nearly any background gas.

Versatile

The unit is compact, lightweight, and suitable for both portable use and permanent installation. The 303B is available with a choice of power sources covering AC, external DC, and internal battery operation.

Fast, accurate measurement

The 303B can be situated close to the sample tap, eliminating long tubing runs and reducing the sample transport time of the process gas which improves the overall measurement response time. The 303B transmits the moisture level to a recorder or control center via its 4-to-20 mA output.

Built-in bypass flowmeter

A built-in bypass flowmeter increases total sample flow to reduce response time. This bypass feature is valuable when the 303B is in portable service – for example, rapidly analyzing moisture in gas cylinders, where it is essential to purge valves, regulators, and tubing of atmospheric moisture prior to taking measurements.

Key benefits

  • Digital moisture indicating meter
  • Solid state electronics
  • Rugged moisture cell
  • Highly accurate, adjustable flow control system
  • Portable, with optional carrying bag
  • Powered by internal battery, DC/AC

Applications

  • Natural gas pipelines and gas treatment processes
  • Air humidity in dry boxes
  • Atmospheres in simulated space chambers
  • Sensing elements in humidity control systems
  • Inert protective atmospheres in brazing or sintering furnaces
  • Moisture in fluorocarbon gases
  • Batch and continuous driers
  • Anhydrous batch chemical processes at start-up
  • Quality control of transistor and diode backfill gas
  • Instrument air systems
  • Cryogenic processes
  • Radar wave guides
  • Other moisture analysis applications

Markets

  • Natural gas
  • Petrochemical
  • Chemical
  • Other moisture analysis markets

3050 Process Moisture Analyzer Series

Designed specifically to monitor the very low moisture levels typically exiting mole sieve dryer systems, the 3050 Process Moisture Analyzer Series helps deliver significant cost savings.
3050 Process Moisture Analyzer Series

Designed specifically to monitor the very low moisture levels typically exiting mole sieve dryer systems, the 3050-DO helps deliver significant cost savings. By providing precise, stable moisture analysis, the 3050-DO enables feedback control of dryer regeneration, which optimizes the regeneration cycle, reduces operational expenses and extends plant uptime.

Reduced maintenance

The stability of the vibrating quartz crystal means the sensor never needs to be sent out for recalibration. Unlike aluminum oxide sensors which require removal from service or an exchange program for routine calibration at the manufacturer, the vibrating quartz crystal continually verifies itself against an internal reference eliminating the on-going maintenance cost for calibration.

Increased uptime

QCM technology delivers precision accuracy, within 0.02ppmv or 10% of the reading. This level of control minimizes the frequency of bed regeneration, which keeps the plant running longer, extends the operating life of the mole sieve bed, and results in lower overall costs.

Peace of mind

Active feedback ensures the 3050-DO constantly monitors
itself for key parameters including oscillation frequency, sample pressure, and operating temperature. Combined with the built-in verification function, you can be confident the analyzer is providing the right readings to protect and optimize your process.

Key benefits

  • Most accurate trace moisture measurement technology available
  • Fastest response to changing
  • moisture levels
  • Specific to moisture in most applications
  • Internal verification system for trusted,
  • stable and accurate readings

Applications

  • The 3050-DO is specifically designed to monitor trace moisture levels exiting mole sieve dryer systems.
  • Other moisture analysis applications

Markets

  • Petrochemical
  • Natural gas
  • Refinery
  • Chemical
  • Other moisture analysis markets

5000 Process Moisture Analyzer Series

The versatile 5000 Process Moisture Analyzer Series is a highly sensitive moisture analyzer for process applications where the continuous, reliable measurement of moisture in vapors and gases is required.
5000 Process Moisture Analyzer Series

The versatile 5000 is a highly sensitive moisture analyzer for process applications where the continuous, reliable measurement of moisture in vapors and gases is required. The analyzer measures moisture on-line by monitoring the vibrational frequency change of a hygroscopically sensitized quartz-crystal that is exposed alternately to wet sample and dry reference gas for 30 second periods. The reference gas is sample gas passed through a molecular sieve dryer to remove virtually all its moisture content. Many moisture analyzers are susceptible to attack by the process stream. Unsaturated hydrocarbons, compressor oils, oxygen, carbon dioxide, and others can permanently damage or destroy trace moisture sensors. Even worse, a fouled sensor can become completely unresponsive to moisture, yet continue to give an output, which could leave your process unmonitored. The 5000’s unique differential measurement principle, combined with continuous diagnostics, ensures reliable performance in critical moisture applications.

Field unit

The field unit is explosion-proof and is certified to comply with numerous international standards. It contains a sample cell, switching valves and associated electronic circuits mounted internally and a flowmeter, flow control valves and back pressure regulator mounted externally.

Controller

Designed for use in industrial areas, the controller is available with several standard and optional certifications. It provides all control and data processing, as well as a keypad and display interface. Outputs include RS-485 bidirectional serial data, two fully configurable 4-20 mA analog signals, and three configurable alarms. It can be separated from the field unit by up to 600 m (2000 ft).

External dryer

The external dryer supplies the analyzer with reference gas, by using a molecular sieve to dry the actual process gas.

Key benefits

  • Reliable performance
  • Internal verification on process gas
  • Fast response
  • Few interferences
  • No process temperature of pressure compensation required
  • Wide-range moisture

Applications

  • Catalytic reforming
  • Moisture in olefins
  • Moisture in natural gas
  • Other moisture analysis applications

Markets

  • Natural gas
  • Petrochemical
  • Refinery
  • Chemical
  • Other moisture analysis markets

2850 Process Moisture Analyzer Series

2850 Process Moisture Analyzer Series is the moisture analyzer of choice for monitoring process desiccant dryers, instrument air dryers, or air separators, and for industrial gas production and quality assurance.
2850 Process Moisture Analyzer Series

The 2850 is the moisture analyzer of choice for monitoring process desiccant dryers, instrument air dryers, or air separators, and for industrial gas production and quality assurance.

Ultra fast response

The 2850 reaches 63% of a steady state reading in less than five minutes, far faster than other moisture analyzers in the 1 to 100 parts per million by volume (ppmv) range. By using unique non-equilibrium measurement techniques, the 2850 provides this exceptional response speed drying-down as well as wetting-up.

Wide measurement range

The analyzer provides ±5% accuracy from 1 to 100 ppmv and indicates to 1000 ppmv. Between 100 parts per billion by volume (ppbv) and 1 ppmv, the measurement is exceptionally valuable as a sensitive trend indicator. Two customer-settable 4-20 mA analog outputs are provided which may be assigned to cover any portion of the operating range.

Internal verification

An internal, NIST-traceable moisture generator adds a known amount of moisture to conditioned sample gas. The resulting wet gas is then directed to the analyzer’s sensor to verify proper sensor and system operation. An alarm contact is provided to alert the operator, if the analyzer fails the verification process. Verification may be initiated on programmable schedule or on manual demand.

Key benefits

  • Most accurate trace moisture measurement technology available
  • Responds quickly to both increasing and decreasing moisture levels
  • Specific to moisture in most applications

Applications

  • Industrial gas production and quality assurance
  • Cryogenic air separation
  • Process dryers
  • Other moisture analysis applications

Markets

  • Air separation
  • Petrochemical
  • Chemical
  • Refinery
  • Other moisture analysis markets

5812 Process Moisture Analyzer Series

5812 Process Moisture Analyzer Series for Reliable moisture in natural gas measurement
5812 Process Moisture Analyzer Series

Measuring moisture in natural gas is not a difficult application, but reliably measuring on a continuous basis is. The 5812 Moisture Analyzer is designed specifically to meet the needs of the natural gas industry for reliable, low maintenance, and self-verifying moisture analysis. The 5812 measures moisture by monitoring the performance of a solid-state, water sensitized quartz-crystal. As wet sample gas passes over the crystal, moisture is sorbed onto the crystal’s coated surface. The crystal is then exposed to dried sample gas and moisture is released. The difference in the wet and dry performance of the crystal is proportional to sample moisture level. This continuous cycling between wet sample and dry sample gases results in the analyzer being constantly ready to detect and respond to changes in moisture. It is the combination of quartz-crystal sensing and asymmetrical sampling which provides the rugged, reliable, continuous performance demanded in natural gas moisture analysis.

Long sensor life

The 5812 has an exceptional sensor life due to its unique asymmetrical sensing technology, which limits the exposure of the sensing element to potentially dirty natural gas. During asymmetrical sensing, the 5812 directs natural gas into the sensor module for 30 seconds, then directs clean, dry gas for the next 9.5 minutes. In each 10-minute measurement period, the sensor module is exposed to dirty natural gas for only 5% of the time. For the remainder of the measurement period, clean gas protects the sensor and strips away volatile contaminants.

Wide performance range

The 5812 is calibrated from 1 to 1000 parts per million by volume (ppmv) and provides trend indication above the calibrated range. Alternative output in pounds per million cubic feet is standard.

True process analyzer features

Data is provided by RS485 digital interface and two fully programmable 4-20 mA analog outputs. Multiple programmable alarms allow the user to monitor both process conditions and analyzer performance. The RS485 is particularly useful for remote monitoring or troubleshooting an unattended 5812.

Key benefits

  • Reliable performance
  • Internal verification on process gas
  • Fast response

Applications

  • Moisture in natural gas
  • Other moisture analysis applications

Markets

  • Natural gas
  • Other moisture analysis markets

5820 Process Moisture Analyzer Series

5820 Process Moisture Analyzer Series for Ideal for critical low-level moisture measurement applications
5820 Process Moisture Analyzer Series

The 5820 is an easy-to-use process moisture analyzer that offers a wide range of performance features: exceptional accuracy, multi-gas compatibility, fast response speed, and a wide measurement range. Equipped with an online verification system, this state-of-the-art analyzer is designed to rapidly build and maintain operator confidence in its moisture analysis.

Multi-gas compatibility

The 5820 combines excellent multi-gas compatibility with an easy-to-use operator interface. A single, simple menu selection is all that is needed to reconfigure the 5820 for a new gas type. The analyzer is compatible with virtually all non-corrosive gases including inert gases (He, Ar, Ne, Xe, Kr), H2, O2, and N2, air, and many specialty gases like sulfur hexafluoride.

Exceptional accuracy

With an accuracy of ±10 parts per billion by volume (ppbv) or ±10% of reading, the 5820 is perfect for moisture applications that require accurate results. Quartz crystal technology and an online verification system combine to constantly provide assurance that the analyzer is continuing to provide you with this superior level of performance.

Wide measurement range

The 5820 accurately measures from 0.01 parts per million by volume (ppmv) to 100 ppmv. While the recommended usable range is between 0.01 ppmv to 100 ppmv, the analyzer will provide measurements up to 1000 ppmv to capture the nature of a process upset.

KEY BENEFITS

  • Quartz crystal technology provides accuracy, speed, and calibration stability
  • Online verification system confirms analytical performance
  • Intuitive, easy-to-use interface with keypad and display allows access to operating variables
  • Multi-gas compatibility for periodic testing of multiple gas samples
  • Menu-driven gas selection eliminates manual adjustments

Applications

  • High purity gas production
  • Semiconductor gases
  • Industrial gas production
  • Quality assurance
  • Air separation
  • Other moisture analysis applications

Markets

  • Semiconductor manufacturing
  • LCD/OLED display manufacturing
  • Other moisture analysis markets

5830 Process Moisture Analyzer Series

5830 Process Analyzer Series for Ideal for critical moisture measurement applications
5830 Process Analyzer Series

The 5830 Moisture Analyzer is an easy-to-use process moisture analyzer that offers a truly remarkable combination of performance features: exceptional accuracy, multi-gas compatibility, fast response speed, and wide measurement range. The 5830 is ideal for critical moisture measurement applications.

Online verification system

This state-of-the-art analyzer is designed to rapidly build and maintain operator confidence in its moisture analysis. The verification system allows the user to challenge the analyzer’s sensor at will with either a zero gas or a NIST-traceable moisture concentration, to check both its baseline stability and responsiveness to real moisture. An alarm contact alerts the operator if the analyzer fails verification. The verification sequences may be started on a programmable schedule or on manual demand.

Multi-gas compatibility

The 303B can be situated close to the sample tap, eliminating long tubing runs and reducing the sample transport time of the process gas which improves The 5830 is completely compatible with virtually all non-corrosive gases, including inerts – helium (He), argon (Ar), neon (Ne), xenon (Xe) and krypton (Kr) – oxygen (O2), hydrogen (H2), nitrogen (N2), air, and many specialty gases such as sulfur hexafluoride (SF6). A single, simple menu selection is all that is needed to re-configure the 5830 for a new gas type.

Fast response speed

The 5830 responds quickly to both increases and decreases in moisture concentration because the analyzer employs a unique non-equilibrium measurement technique. This technique continuously exposes the sensor to “wet” sample gas followed by “dry” sample gas to make its moisture analysis. With this technique, the analyzer never needs to wait for the sensor to reach equilibrium to establish its accurate measurement.

Wide measurement range

The 5830 responds quickly to both increases and decreases in moisture concentration because the analyzer employs a unique non-equilibrium The 5830 accurately measures from parts per million by volume (ppmv) (20 parts per billion by volume (ppbv) to 100 ppmv). While the recommended usable range is between 0 and 100 ppmv, the analyzer will provide measurements up to 1000 ppmv so the user can capture the nature of a process upset.

Key benefits

  • Exceptional accuracy at ±20 ppbv or ±10% of reading
  • Multi-gas compatibility
  • Menu-driven gas selection eliminates all manual adjustments
  • On-line verification system confirms analytical performance

Applications

  • Natural gas pipelines and gas treatment processes
  • High purity gas production
  • Semiconductor gases
  • Industrial gas production
  • Quality assurance
  • Other moisture analysis applications

Markets

  • Natural gas
  • Petrochemical
  • Chemical
  • Other moisture analysis markets

5920 Process Moisture Analyzer Series

The 5920 is an easy-to-use process moisture analyzer that offers a wide range of performance features: multi-gas compatibility, exceptional accuracy, on-line verification, fast response speed, and wide measurement range. Equipped with an on-line verification system, this state-of-the-art analyzer is designed to rapidly build and maintain operator confidence in its moisture analysis.

5920 Process Moisture Analyzer Series
5920 Process Moisture Analyzer Series

Multi-gas compatibility

5920 combines the excellent multi-gas compatibility with an easy-to-use operator interface. A single, simple menu selection is all that is needed to reconfigure the 5920 for a new gas type. The 5920 is compatible with virtually all bulk, ultra-high-purity gases including inerts – helium (He), argon (Ar), neon (Ne), xenon (Xe), krypton (Kr) –
hydrogen (H2), oxygen (O2), and nitrogen (N2).

Exceptional accuracy

With an accuracy of ±1 parts per billion by volume (ppbv)or ±10% of reading, the 5920 is perfect for moisture applications that require stable and accurate results. Quartz-crystal technology and an on-line verification system combine to constantly provide assurance that the analyzer is continuing to provide you with this superior level of performance.

Wide measurement range

The 5920 accurately measures from 1 to 150 ppbv. While this is the recommended operating range, the analyzer will provide trend indication up to 1000 ppbv, so that you can capture the nature of a process upset.

Key benefits

  • Quartz-crystal technology provides accuracy, speed, and calibration stability
  • Online zero gas verification confirms analytical stability
  • Intuitive, easy-to-use interface with keypad and display allows access to operating variables
  • Rack-mount design makes the analyzer ideal for analytical carts
  • Menu-driven gas selection eliminates all manual adjustments

Applications

  • Continuous emissions monitoring system
  • Spot monitoring
  • Cylinder
  • High purity gas production
  • Other moisture analysis applications

Markets

  • Semiconductor manufacturing
  • LCD/OLED display manufacturing
  • Air separation
  • Other moisture analysis markets

Need help choosing your moisture analyzer?

ASaP practical solutions

The practical solutions of ASaP are based on decades of experience, specific education, knowledge of the team members and, last but not least, the joy in our work. The well-established and complementary ASaP package of services and products is an important contribution to the right solutions for your analytical needs. Moreover, the team spirit and the cooperation with specific partners give us the opportunity to design, build, locally install and commission tailor made analyzer systems for you. All these products and systems can be carried out according to the latest guidelines, such as ATEX.

ASaP is a reputable provider of analytical solutions; We can provide you with a full-service package including engineering, manufacturing, offshore service, analyzers, system integration, and cutting-edge LNG Custody Transfer Systems (CTMS), LNG Probe-Vaporizers, advanced LNG Samplers, and precise NG analysis systems. You are kindly invited to consult us on any analytical challenge!