Moisture analysis – How to choose a moisture analyzer?

303B Process 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.

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.

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.

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.

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.

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.

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.

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.

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.