Dew-Point Sensors, Dew-Point Meters and Sampling Systems

Field-proven humidity, dew-point & moisture sensors for accurate and reliable moisture measurement in gases and liquids

Compressed Air

Moisture in Liquids 

Medical Gas

CNG Stations

Trace Moisture

 More...

Michell's range of sensors allow for measurements of dew-point, moisture content and trace moisture in both gases and liquids. From extremely dry parts-per-billion measurements (-120°Cdp) to high-humidity conditions with dew-points up to +60°C, our sensors are designed to reliably measure moisture in a wide range of applications. Our globally approved intrinsically safe and explosion-proof/flame-proof transmitters are available for use in hazardous areas.

Michell has 40 years of expertise in designing, manufacturing, and calibrating humidity & moisture sensors, moisture meters and other instrumentation, based on a range of technologies. We continuously invest in research to improve our moisture sensing technologies. This includes our range of dew-point transmitters, which are based on our widely used and field-proven ceramic impedance technology.


NEW Application Section leads with Compressed Air.


Compressed Air
For 40 years Michell has been the leading supplier of dew-point sensors and portable moisture spot check instruments for moisture content on ISO 8573-1 Class 1,2 and 3 compressed air dryers.

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Industrial Dew-Point Sensors, Dew-Point Transmitters and Dew-Point Meters

Easidew Dew-Point Transmitter Series
Easidew Dew-Point Transmitter Series
Rugged and reliable industrial, loop-powered dew-point transmitter with a 5/8\ UNF or 3/4\" UNF process connection. The wide -100/+20°C (-110/+20°C Easidew 34) dew point measurement range makes it suitable for all industrial dryer applications. Available with MiniDIN 43650 C or M12 electrical connectors.

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Easidew 34 - Dew-Point Transmitter
Easidew 34 - Dew-Point Transmitter
Rugged and reliable industrial, loop-powered dew-point transmitter with the US industry standard 3/4\ UNF process connection. The wide -110/+20°C dew point measurement range makes it suitable for all industrial dryer applications."

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Easidew I.S. Dew-Point Transmitter - For Hazardous Area Applications
Easidew I.S. Dew-Point Transmitter - For Hazardous Area Applications
Intrinsically safe dew-point transmitter, based on field-proven Easidew transmitter technology. IECEx, CSA, FM, Gost K/R and ATEX certification makes the Easidew I.S. ideal for all global hazardous area applications. 5/8\ UNF G1/2\" BSP or 3/4\" UNF process connections."

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SF52 - Dew-point Transmitter
SF52 - Dew-point Transmitter
Fast-responding, cost effective dew-point transmitter designed for use in harsh industrial dryer applications. Available with G1/2\ or 1/2\" NPT process connections."

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Easidew Online - Dew-Point Hygrometer
Easidew Online - Dew-Point Hygrometer
A cost effective ppmV / dew-point meter including an Easidew Transmitter and digital display with analogue and digital outputs and dual alarms.

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SF72-TX-Rail - Dew-Point Transmitter for Rail Applications
SF72-TX-Rail - Dew-Point Transmitter for Rail Applications
A cost-effective moisture transmitter designed to continuously monitor the performance of the compressed air dryers on railway rolling stock to ensure both safety and efficiency of braking and other systems.

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Easidew Advanced Online - Dew-Point Hygrometer
Easidew Advanced Online - Dew-Point Hygrometer
A versatile touch-screen dew-point hygrometer with pressure compensation. This display provides analog, digital and 4 programmable relay alarm outputs with front screen or software app display configuration.

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SF82 Dew-Point Transmitter
SF82 Dew-Point Transmitter
Rugged and reliable fast response dew-point transmitter with a 5/8 UNF, ¾ UNF or G1/2 process connection. The sensor has analog and digital electrical outputs with MiniDIN 43650 C or M12 electrical connectors, which make it ideal for use in higher temperature compressor room type applications.

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SF82 Online - Fast-Response Dew-Point Hygrometer
SF82 Online - Fast-Response Dew-Point Hygrometer
Easy to install and maintain, the SF82 Online Fast Response Hygrometer measures and displays dew point and moisture content for use in a wide range of moisture applications. The SF82 Online display provides analog, digital and dual relay alarm outputs.

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Cermet II Hygrometer  - Reliable On-Line Dew-Point Measurement
Cermet II Hygrometer - Reliable On-Line Dew-Point Measurement
A full specification on-line hygrometer with wide operating range and multiple display options. Includes Cermet II transmitter, based on Easidew technology with digital output.
Obsolescence Notice from December 2022

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DryCheck Hygrometer / Sampler - Self-Contained Dew-Point Instrument
DryCheck Hygrometer / Sampler - Self-Contained Dew-Point Instrument
A simple and efficient, self-contained dew-point hygrometer based on Easidew technology, with filtration and flow control, for measurement of dew point or moisture content.

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Easidew Sampler - Low Cost Self-Contained Sampling System
Easidew Sampler - Low Cost Self-Contained Sampling System
A low-cost, self-contained sampling system, with filtration and flow control, for measurement of either pressure or atmospheric dew points.

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Process Dew-Point Sensors, Dew-Point Transmitters and Dew-Point Meters

Easidew PRO I.S. - Intrinsically Safe Dew-Point Transmitter
Easidew PRO I.S. - Intrinsically Safe Dew-Point Transmitter
Intrinsically safe transmitter for moisture measurement in gases and liquids, supporting ppmv, ppmw and dew-point output with ±1°C accuracy. IECEx, CSA, FM, Gost K/R and ATEX certified. 5/8 UNF process connection.

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Easidew Pro XP Transmitter - Explosion Proof Moisture Transmitter
Easidew Pro XP Transmitter - Explosion Proof Moisture Transmitter
Explosion proof dew-point transmitter, with ±1°C dew-point accuracy. IECEx, cQPSus, and ATEX certification makes the Easidew PRO XP ideal for a wide variety of explosion proof /flameproof rated applications. 3/4\ UNF process connection. Now available in a Service Exchange version.

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Intrinsically Safe Field Display - for use with Easidew I.S. and Easidew PRO I.S.
Intrinsically Safe Field Display - for use with Easidew I.S. and Easidew PRO I.S.
ATEX, IECEx, and FM certified, 4-digit loop-powered local monitor for the Easidew PRO I.S. and Easidew I.S. transmitters. IP66 enclosure.

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ES20 Compact Sampling System - Stainless Steel Sampling System
ES20 Compact Sampling System - Stainless Steel Sampling System
An economical, high quality sampling system, with a variety of enclosure, filtration, pressure, and tube fitting options.

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ES70 Sampling System
ES70 Sampling System
The ES70 series sampling system is designed to simplify system configuration by providing a set of choices for all requirements, such as panel or enclosure mount, filtering, upstream and downstream pressure and flow control etc.

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Moisture / Dew-Point Sensors for Pure Gases

Additional Information


High volume supply capabilities with consistently short lead times

As the largest manufacturer of dew-point transmitters in Europe, Michell Instruments has over 2000 transmitters under calibration at any moment in time, in our own production facility in Ely, UK, in addition to local calibration centres in Netherlands, France, Italy, Germany, China, Japan and USA.

Our manufacturing processes are optimized to meet high-volume ‘just in time’ agreements with major industrial equipment suppliers, and thousands of hygrometers leave our factory every month to measure and control moisture in some of the most demanding applications and locations around the world.

Sensor Service Exchange - A cost effective programme with zero down time


It is important all instruments are re-calibrated regularly to maintain accuracy and traceability. With Michell Instruments' unique Sensor Exchange Programme this can be achieved cost effectively and with virtually no down time. Simply request an exchange sensor from Michell or a local representative, then return your old sensor to us once you have removed and replaced it with the exchange sensor. All your calibration data is stored within the sensor, and each sensor comes with a traceable calibration certificate as standard.

Sensor Recalibration Program


Where Sensor calibration traceability is important, Michell offers an efficient recalibration service at our global service centres. Simply return the sensor to us, requesting the required calibration procedure and we will calibrate and return the sensor with a new traceable calibration certificate.

Customised products with worldwide support


If our standard products don’t quite meet your requirements, our team of process engineers and systems designers can work with you to take your project from the design and consultation phase, right through to manufacturing and commissioning. Our 10 global sales and service centers in Americas, Europe, Middle East and Asia and our worldwide distributor network are always on hand to provide support for your challenging applications. Click here to get in touch today.

Related Products

When warm compressed air leaves the compressor it will contain a high moisture content in the form of water vapour. Drying the air is important to prevent condensation forming in the distribution network, or at point of use.

Regenerative twin-column desiccant dryers are the most effective type of dryer. Measuring the dew-point at the dryer enables the columns to be switched-over only when performance in the active column starts to deteriorate, resulting in cost savings when air demand is low. This is known as dew-point dependent switching (DDS). More sophisticated DDS dryers also measure the inactive column to determine exactly when it has been regenerated, resulting in large savings in purge air and heating costs.

Measuring the amount of dissolved moisture dispersed throughout an immiscible process liquid is possible through the application of Henry’s Law. The transmitter calculates the moisture content using the measured water vapour pressure, saturation vapour pressure, and the user-entered saturation constant of the liquid.


  • Naphtha feedstock to isomerization catalyst
  • Hexane solvent in HDPE and LDPE process
  • Benzene in styrene manufacture
  • LNG LPG production and product checking
  • Diesel and aero-fuels to avoid liquid water phase separation
  • BTX process monitoring - benzene, toluene and xylene

High levels of water vapour in medical or breathing gases make them uncomfortable to breath and promote the growth of unwanted bacteria.

Pharmacological regulations state that the gases should periodically be tested to ensure that their dew point is sufficiently low.

More than 3 million vehicles world-wide are equipped to run on compressed natural gas, and the number of CNG filling stations is growing too. The ISO 15403:2000(E) states that ‘the single most important safety requirement of CNG fuel is a very low water dew-point to preclude the formation of liquid water at any time’.


  • Ethylene gas & solvent liquid dehydration in polymer plants
  • Aromatic hydrocarbons in BTX plants
  • Butadiene in synthetic rubber manufacture

For applications where keeping moisture levels as low as possible is of critical importance, sensitivity to (ppbV and ppmV) are required. Our advanced quartz crystal microbalance technology can help.


  • High purity gas production
  • Semiconductor grade gases
  • Industrial gas production
  • Specialist and cylinder gases

The applications for our dew-point transmitters are not limited to those listed on this page.


We have over 40 years experience measuring humidity & performing calibrations and can help you choose the best product for your application.