Quartz technology boost for moisture
15 Jan 2000
Traditional aluminium oxide-based moisture analysers are under threat from a new quartz-crystal-based instrument from Ametek Process Instruments.
Until now the quartz-crystal technology has only been available at a premium price, but the Model 3050 OLV analyser is the first in the aluminium oxide price range to offer real-time performance verification, on demand, and an end to the problem of `dying in place'.
According to Ametek, aluminium oxide probes are notorious for their slow speed of response, a problem made even more acute if the analyser, with its permeable metallic electrode, has to dry down from a high moisture reading. This can take up to eight hours, whereas with quartz-crystal technology moisture molecules do not permeate the sensor but sit on its surface and can be quickly swept away.
`Dying in place' happens when a fouled aluminium oxide sensor becomes unresponsive to moisture but continues to give an output signal - leaving the process unmonitored and unprotected with no alarm indication either on the instrument or in the control room. Quartz crystal sensors, however, are far less susceptible to fouling and damage by process stream chemicals.
