top of page


Available at Alpha Process Sales - LA 


Michell Instruments is an international leader in high-precision sensing with 40 years’ experience in the field, specializing in instrumentation for dew point, relative humidity and oxygen analysis.


The company serves industries as diverse as petrochemical and pharmaceutical to power generation and food processing.




A fast-responding, easy to use, portable hygrometer for measurement of dewpoint and moisture content of compressed air and other gases.

Simple Operation: The menu-driven display, easily accessible gas connections and application software allow the user to quickly and easily set up the HygroPort and make measurements within minutes. All measurement parameters are available at the touch of a button. The numerous features are easy to navigate with our intuitive interface and multiple, large LCD displays.


Features & Benefits

  • FM/CSA certified for Class I, Division 1, Groups A, B, C, D hazardous environments

  • Dewpoint measurements from -148°F to +68°F; ±1.8°F typical dewpoint accuracy

  • Fast-responding internal ceramic sensor

  • Second process input channel for external transmitter

  • Internal data logging facility (log up to 320,000 points)

  • Bluetooth wireless interface to application software

  • 1/8" NPT inlet and outlet gas connections; stainless steel gas wetted parts

  • Pressure compensated PPMv, Lb/MMSCF or g/m3 measurements

  • 50 micron stainless steel sintered disk filter in the inlet port


Trace moisture measurement is essential for ensuring quality, safety and efficiency in thousands of applications across a wide range of industries. Water vapor is a serious contaminant in many processes, having a detrimental effect on the quality and integrity of final products. Water dew point is a specific category of moisture measurement and is the most common parameter selected when condensation or ice formation is to be avoided.
Applications for trace humidity range from medical breathing air and monitoring industrial dryers through to monitoring the dew point in natural gas to ensure it complies with international quality standards.
Dew-Point Transmitters
  • Dew-point sensors are easy to install and maintain

  • Measure dew point, moisture content and trace moisture in both gases and hydrocarbon liquids

  • Available with a sensor exchange program to minimize maintenance time, they are reliable and cost-effective.

  • Ceramic Metal-Oxide Moisture Sensor covers extremely dry parts per billion measurements (-120 °C dew point)

  • Polymer moisture sensor operates between -60 and +60 °C dew point and provides very fast responses to changes in moisture

  • Base transmitters can be supplied with sample conditioning systems for reliable and consistent measurements and displays for easy operation


Portable Hygrometers
  • Designed for daily use in demanding industrial environments they are housed in tough, durable cases rated to IP66/NEMA 4. Long battery life allows up to 48 hours of standard operation between charges and is ideal for field use in remote locations.

  • Calibrated traceable to National Standards (NPL and NIST). Alternatively, they can be calibrated in our UKAS Accredited calibration lab in accordance with the ISO17025 standard for testing and calibration laboratories.

  • Appropriate sample conditioning ensures optimal performance from your portable dew-point hygrometer. 

  • Easidew Portable and MDM50 both feature an integral sample conditioning system, while various sampling options are available for the MDM300 and MDM300 I.S.

  • The portable trace moisture hygrometers use Easidew and SF82 Dew-Point Transmitters, which are part of Michell’s sensor exchange programme. Under this scheme, users can keep their instruments fully calibrated with the minimum of downtime.


Precision Chilled Mirror Reference Hygrometers
  • Chilled mirror dew-point hygrometers measure the actual formation of liquid water on a temperature-controlled surface to determine the dew-point of the sample gas. 

  • Optimized for specific applications that require high-temperature or humidity, trace moisture or fast-response.

  • The S8000 and Optidew ranges share a common HMI and operating system making it simple for operators to transition between instruments. 

  • The operating system is intuitive, and the touch screen display makes setting parameters and logging quick and easy to do.


Humidity & Temperature Calibration
  • For cost-effective humidity calibrations on-site, these stable and reliable humidity generators can be used in combination with a chilled mirror reference for full traceability. 

  • Fully automatic, computer-controlled humidity calibration systems provide humidity generation, a climatic chamber and chilled mirror reference for professional calibrations.

  • Complete dew-point calibration package with optional compressor, dryer, dew-point generator, reference instrument and optional manifold. Capable of providing trace moisture calibrations down to -100 °C dew point


Trace Moisture Analyzers for Natural Gas Quality & Petrochemical Applications
  • Levels of moisture in natural gas are tightly controlled by international quality standards. The moisture analyzers provide online dew-point measurements of to ensure producers and gas transmission networks meet these requirements. Monitoring the moisture in the gas helps operators to save energy on natural gas dryers. Portable dew-point analyzers allow for spot checks at critical measurement points.

  • Moisture affects the quality of petrochemical products, disrupts processes and may lead to corrosion. Online process moisture analyzers not only improve quality but reduce the need for unscheduled maintenance or stoppages by avoiding damage to equipment and materials.

  • The analyzers and sampling systems meet the hazardous area safety standards from ATEX, IECEx, FM, cCSAus and GOST. 

  • The enclosed sample systems not only protect the instruments from weather but can also include heating and cooling systems to maintain optimum operating temperatures. As well as the standard stainless-steel sampling systems, Michell’s Systems Engineering department also provide custom designs for specific applications or combinations of instruments.

Hydrocarbon Dew-Point Analyzers for Natural Gas
  • The Condumax II is based on the patented Dark Spot chilled mirror sensor for fully automatic measurements of hydrocarbon condensate formation. We developed the Dark Spot™ hydrocarbon dew-point sensor in collaboration with Shell Research, and this now the accepted industry standard for fully automatic measurements of natural gas quality. For water dew-point measurements, it uses Michell’s Ceramic Metal-Oxide Moisture Sensor.

  • Standard and custom-designed sampling options are available. These include combinations of flow, temperature and pressure control as well as enclosure heating to ensure optimal sampling conditions.

  • The instruments are certified for use in zone 1 and zone 2 hazardous areas, with certification from IECEx, ATEX, CCSAUS, CQPSUS, and GOST Ex. 

Moisture in Hydrocarbon Liquid Analyzers
  • The Liquidew moisture in liquid analyzers are based on Michell’s Ceramic Metal-Oxide Moisture Sensor. This versatile moisture sensor is capable of both moisture in gas as well liquid measurements and means that the Liquidew analyzers are eligible for the sensor exchange program.

  • The moisture analyzers are designed for flammable and non-flammable liquid within hazardous areas. They carry global hazardous area certification from IECEx, ATEX, cCSAus, TR CU, FM and GOST.

  • Sample conditioning is essential for getting the best accuracy for moisture measurements in hydrocarbon liquids. Michell offer fully enclosed or panel-mounted sampling systems which feature flow control and particulate filtration.


SF82 Dewpoint Transmitter
  • Rugged design for wet environments and high humidity

  • -76°F to +140°F (-60°C to +60°C) dewpoint range

  • 0 to 24,000 PPMv moisture content

  • Linear 4-20 mA signal, MODBUS RTU digital output (optional)

  • 2-wire loop powered configuration

  • Accuracy to ±3.6°F

  • NIST traceable


Pura High Purity Gas Dewpoint Transmitter
  • Measure trace moisture in high purity gases

  • Dewpoints from -184°F (<1ppbv) to -40°F

  • VCR gas connection ports

  • 4-20mA and RS485 outputs

  • Pressures from 10-9 Torr to 3500 PSIG

  • Internal 0.25 Ra µm electro-polished finish

  • Fast response


HygroPort Portable Hygrometer
  • Dewpoints from -148°F to +68°F

  • Rugged thermoplastic case; NEMA 4 rated

  • Digital display, user selectable ranges and units

  • Fast-responding internal sensor

  • Second process input channel (4-20 mA) for external transmitters

  • Internal data logging facility (log up to 320,000 points)

  • Bluetooth wireless interface to application software

  • 1/8" NPT inlet and outlet gas connections; stainless steel gas wetted parts

  • 20 micron stainless steel sintered disk filter in the inlet port

  • Pressure and temperature compensation capabilities


HygroPort I.S. (Intrinsically Safe) Portable Hygrometer
  • FM/CSA certified for Class I, Division 1, Groups A, B, C, D hazardous environments

  • Dewpoint measurements from -148°F to +68°F; ±1.8°F typical dewpoint accuracy

  • Fast-responding internal ceramic sensor

  • Second process input channel for external transmitter

  • Internal data logging facility (log up to 320,000 points)

  • Bluetooth wireless interface to application software

  • 1/8" NPT inlet and outlet gas connections; stainless steel gas wetted parts

  • Pressure compensated PPMv, Lb/MMSCF or g/m3 measurements

  • 50 micron stainless steel sintered disk filter in the inlet port


 Easidew Plus Portable Hygrometer
  • Dewpoints from -58°F to +68°F

  • Accuracy to ±3.6°F

  • Pressures to 4300 PSIG

  • Exceptionally fast response

  • °F or °C display

  • Integrated sample system

  • NEMA 6 enclosure


Dew-Point Transmitter - Michell Easidew EA2.png
Portable Dew-Point Hygrometer - Michell MDM300 Series.png
Industrial Grade Chilled Mirror Hygrometer - Michell Optidew.png
Cost Effective Humidity Validator - Michell S904.png
Moisture in Natural Gas Analyzer - Michell OptiPEAK TDL600.png
Hydrocarbon Dew-Point Analyzer - Michell Condumax II.png
Trace Moisture & Dew-Point Measurement & Analysis


These instruments thermo-electrically chill a mirror surface until dew or frost begins to form, providing the most fundamental measurement of dew or frostpoint. Formation of dew or frost is precisely monitored by an electro-optical system; measurements are traceable to national and international standards. To account for the buildup of contaminants on the mirror surface, Kahn's system incorporates Automatic Balance Compensation (ABC). Periodically, the instrument automatically heats the mirror to vaporize the accumulated dew or frost, recalibrates itself for altered reflectivity due to contaminants, then returns to normal measuring.
Optidew Optical Dewpoint and RH Transmitter
  • Dewpoint, temperature and RH measurement
    Fundamental method of dewpoint and RH measurement
    Range:-40°F to +248°F; 0.45 to 100% RH
    Accuracy of ± 0.27°F
    Single, two stage and harsh environment sensor options
    Dual 4-20mA outputs; Alarm relay


Optisure Optical Hygrometer
  • Dewpoints from -76°F to +104°F
    Fundamental method of dewpoint measurement
    Accuracy to ± 0.18°F
    Internal and remote sensor options
    Dynamic Contamination Correction (DCC)
    4-20mA, 0-20mA, and 0-1 VDC outputs
    USB, MODBUS RTU digital outputs




Kahn offers off-the-shelf and custom designed calibration equipment to allow independent verification of the accuracy of your Kahn or other brand humidity sensors. We can design an entire system for you or you can purchase a fully capable, standard system.
Opti-Cal Humidity Calibrator

Stand-alone calibrator for relative humidity (RH) sensors providing automated humidity and temperature profiling with a built-in, NIST traceable, optical reference hygrometer.

  • Perform RH sensor calibration in-house

  • Digital control of temperature and relative humidity

  • Range 10% to 90% RH from 10° to 50°C chamber temperatures

  • Large, 122 cubic inch chamber

  • Integrated, precision, reference hygrometer with Windows application software

  • Best RH measurement capability <2% of reading


HG-1 Humidity Generator

Bench-mount calibrator for manual calibration of relative humidity and dewpoint sensors including aluminum oxide, ceramic and optical probes.

  • Manual calibration of dewpoint and relative humidity

  • Range 10% to 90% RH and -50°C to +50°C dewpoint

  • Accomodates up to 6 sensors

  • Integrated, precision, reference hygrometer

  • Best RH measurement capability <2% of reading; best dewpoint measurement capability ±0.2°C


bottom of page