High precision ultrasonic chilled surface dew point hygrometry

• Main Authors: MILEHAM RUSSELL D, GALIPEAU DAVID W
• Format: Patent
• Language: English
• Published: 11.12.2001
• Edition: 7
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

A improvement for high precision ultrasonic chilled surface dew point hygrometry for measuring the density of condensation and the temperature at the same location on the surface of the sensor. The improvement for high precision ultrasonic chilled surface dew point hygrometry includes a piezoelectric substrate, and further having a conventional thermoelectric cooler connected thereto and a plurality of spaced heat sinks conventionally depending from the surface. Conventional acoustic devices are used to propagate surface acoustic waves and surface skimming bulk waves across the surface of the sensor. A series of the surface acoustic waves is used to measure the density of the condensation at a particular location on the surface of the sensor. A conventional wave detection device such as a phase detector detects the waves as to their velocity and amplitude and passes this information onto a computer microprocessor which is programmed to measure and control the density of the condensate located along the path of the waves across the surface of the sensor. A series of surface skimming bulk waves are preferably propagated across the surface of the sensor at generally an angle to the surface acoustic waves so as to measure temperature of the surface of the sensor without interfering with the surface acoustic waves. Other temperature measuring techniques can also be used, one of which includes using a conventional integrated resistive temperature device disposed in a nonobvious configuration so as not to interfere with the surface acoustic waves on the surface of the sensor.