Precision Hygrometers take readings from ice crystals.
Press Release Summary:
Capable of giving moisture readings down to -40°Cdp, Optidew chilled mirror instruments incorporate Frost Assurance System Technology (FAST) to provide accuracy and reliability. FAST ensures that, for temperatures below 0°C, the dew point reading is derived from ice crystals rather than water droplets. Using routine where mirror temperature is controlled and adjusted at certain levels, instruments help eliminate errors experienced in cases where water does not freeze at 0°C.
Original Press Release:
NEW Frost Assurance System Technology (FAST) to Improve Accuracy of Chilled Mirror Hygrometer
Michell Instruments has introduced a new technology to improve the accuracy and reliability of their chilled mirror instruments. The Frost Assurance System Technology FAST) works by ensuring that, for temperatures below 0°C, the 'dew point' reading is derived from ice crystals, rather than water droplets.
This system is now incorporated into the Optidew range of chilled mirror instruments. Although these precision hygrometers are already highly accurate and capable of giving moisture readings down to -40°Cdp, some applications need even higher levels of accuracy.
Water doesn't always freeze at 0°C - under certain conditions super-cooled water can exist at much lower temperatures. This can be caused by contaminants in the gas under test, or even build up of residue on the chilled mirror surface. Super-cooled water condenses at a slightly different temperature to 'normal' ice formation, and the errors can be as high as 10%.
Michell Instruments FAST technology was developed to avoid this effect by taking a special routine where the mirror temperature is controlled and adjusted at certain levels. The result is that accurate and reliable readings can be taken repeatable without human intervention.
For further information on how FAST increases the accuracy of a Chilled Mirror Hygrometer or the Optidew Precision Hygrometer range please contact:
Jack Herring, Sales and Marketing Manager North America
Michell Instruments Inc
11 Old Sugar Hollow Road
Danbury, CT 06810
Tel: (203) 744-6881
Fax: (203) 743-2051
e-mail: jack.herring@michell.com.
