Chilled Mirror

Experts in Humidity Measurement & Calibration Systems | Chilled Mirror Hygrometers

We are internationally recognized as a developer and manufacturer of the high-quality MBW Calibration chilled mirror dew point hygrometers used in a variety of humidity calibration, measurement and gas quality applications.  Most notably, our MBW instruments provide the calibration traceability for many laboratories such as humidity instrument manufacturers and National Metrology Institutes.  MBW chilled dew point mirrors continue to be chosen as transfer standards for inter-laboratory comparisons both regionally and internationally.

Our MBW chilled mirror condensation technology provides highly precise, stable, and repeatable results. Water vapor condenses onto a temperature-controlled mirror surface and this ‘dew point’ is detected with advanced optical electronics. Since dew point is specific to water vapor concentration and not temperature dependent, measurement precision is consistent across the full application range including high temperature and humidity conditions in climatic test chambers.

Despite its high performance and specification, our MBW Model 373 is easy to use and simple to maintain.  It is typically used as a calibration transfer standard, meteorology reference, in fundamental research projects, trace humidity measurement, critical process monitoring, and fuel cell research applications.  The touch panel user interface is simple and intuitive to use and enables even inexperienced users to perform measurements successfully. Even early instruments remain serviceable thanks to the use of industry standard components and careful control of software build records.  A unique feature of the 373 is its dual mirror PRT configuration.  In standards laboratories, this means that the user can use an external resistance bridge to measure the mirror temperature independent of the 373 electronics so that measurement uncertainty can be reduced, and long-term stability maintained in the event of changes to the 373 measurement electronics.  The latest 373 developments include improved materials of construction to further reduce sorption effects, higher pressure capability based on new measuring head designs, data acquisition software with automated humidity generator control, and multichannel thermometer data integration.

Cost-effective humidity measurement solution to monitor industrial and commercial environments

Our MBW chilled mirror hygrometers have a typical service life of more than 15 years thanks to the use of high-quality materials and Swiss precision engineering. The high-quality platinum resistance thermometer (PRT) element embedded within the mirror ensures excellent long-term measurement stability. Thanks to the precise dew point and temperature measurements as well as the stability and long service life, our MBW chilled mirrors are used by national standards and accredited laboratories worldwide. 

Climatic chambers are in widespread use across many industries. They are used to simulate climatic conditions including temperature, humidity, pressure, vibration and light intensity. Conditions must be controlled and varied according to user or test specifications. Products and samples are placed within the controlled environment according to defined test specifications that require certain conditions to be maintained. Examples include 40 °C / 75 %rh for drug stability and 85 °C / 85 %rh for electronic component testing. Confirmation that the correct environmental conditions have been achieved is a pre-requisite for compliance with the respective standards that apply in each industry.  Our MBW products can provide the simulation of climatic conditions including temperature, humidity, pressure, vibration and light intensity.  You can find our products in automotive component test chambers, pharmaceutical stability chambers, calibration test chambers, and military electronics testing.

Chilled mirror dew point hygrometers are used as reference standards in national and accredited laboratories, and increasingly for industrial applications such as climatic chamber calibration and validation. There are different types available to measure dew/frost points over the entire water vapor range from -95 °C frost point to +95 °C dew point. 

Temperature and Relative Humidity Uniformity

Measurement of temperature uniformity is the most important measurement when calibrating or validating climatic chambers. It is also typically the largest uncertainty contribution. The MBW T12 is a high precision multi-channel thermometer that is suitable for measurement of temperature uniformity in climatic chambers. It is combined with specially performance Pt100Ω platinum resistance thermometers (PRT) that are compact, precise and stable. 

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Reliable Humidity Measurement & Calibration Systems for High Purity Applications


  • Climatic chamber validation to IEC60068
  • Fuel cell research
  • Climatic test chambers
  • Humidity generators
  • Calibration systems
  • Meteorology
  • Climate research
  • On-site calibration of dew point sensors
  • Breathing gas quality
  • Compressed air systems
  • Standards laboratories
  • Validation of production and storage conditions
  • Dryer performance tests


  • Improved reliability
  • Low cost of ownership 
  • Meet compliance requirements
  • Backed by global service and support

Process Insights is committed to solving our customers’ most complex analytical and process challenges.  


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