Product category:
Humidity and Environmental Sensors
News Release from: Michell Instruments | Subject: Optidew
Edited by the Engineeringtalk Editorial
Team on 18 March 2003
Humidity verification for environmental
chambers
The Optidew cooled mirror dewpoint hygrometer is stable, fast responding and accurate over the whole operating range of an environmental chamber, from the driest conditions to saturation.
Environmental chambers are widely used for the testing of a huge range of products, such as electronic equipment, pharmaceuticals and food packaging Historically, wet/dry bulb psychrometers and capacitive relative humidity probes have been used both for the control and validation of such chambers
This article was originally published on Engineeringtalk on 3 Jun 2002 at 8.00am (UK)
Related stories
High accuracy from novel cooled-mirror technology
Michell Instruments reckons it is setting new standards of precision and reliability with the launch of Optidew, its latest cooled mirror dew point measurement technology.
Dewpoint meter is precise about humidity
Optidew Vision is a precision dewpoint meter with an LCD panel.
However, neither is particularly suitable for the highest level of validation of chamber performance.
Now, for the first time there exists an alternative in the form of a cooled mirror transmitter offering improved measurement capability and a flexibility that can be applied over a wide range of environmental conditions with ease.
In the past, a cooled mirror dew-point hygrometer was regarded as an expensive laboratory reference device that would be used for the calibration of lower specification instruments, such as psychrometers and RH sensors.
Further reading
Dewpoint sensor works at higher temperatures
A novel cooled mirror dewpoint sensor is capable of high temperature measurements.
Dewpoint sensors aid fuel cell development
A successful evaluation trial has led a major fuel cell development company to purchase four high-performance Optidew Vision optical dewpoint meters.
Limitations in electronics and in the design of early cooled mirror sensors rendered them inflexible when presented with extremes of temperature and humidity.
The design and development of Optidew has addressed these limitations and resulted in a cooled mirror dew-point hygrometer that is stable, fast responding and accurate over the whole operating range of an environmental chamber, from the driest conditions (typically -40C dewpoint) to saturation at the highest operating temperatures, automatically and without any need for user intervention.
The pedigree of the cooled mirror dew-point hygrometer as a calibration reference device is well established and Optidew follows in a long tradition.
Four-wire resistance temperature measurement, precision digital control and high quality sensor components with a corrosion-resistant hard gold mirror ensure reliable and accurate performance.
Calibration traceability to international standards (NPL and NIST primarily) along with the option for direct UKAS calibration make it suitable for verification of chamber performance, humidity profiling and for the calibration of chamber humidity control loop sensors.
But can Optidew replace those psychrometers and RH probes as the main measurement and control device for an environmental chamber? The results of independent tests suggest that this is possible.
The combination of Optidew's own intelligent control system and the improved sophistication of microprocessor based environmental chambers means that such an advanced, fundamentally based measurement system can now be applied with success to the control of enclosed environments. Request a free brochure from Michell Instruments ...
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