Dew point measurement and time trend analysis
AssigneeGeneral Signal Corporation
InventorCarl E. Schwab
Life of this patent
Estimating the term…
Abstract
A method and apparatus for determining the dew point or dew point depression which is arranged for unattended operation and is extremely accurate in the vicinity of very small dew point depressions. In addition to measuring present dew point depression, historical records are maintained and the device is arranged to perform a time trend analysis so as to provide for short term future prediction. Output is provided via a voice synthesizer and a radio. Dew point depression is computed by determining the adiabatic change in volume required to produce condensation. The change in volume is produced by rapidly expanding a test chamber. The measurement cycle concludes with a compression step to raise chamber temperature to at least freezing.
Claims15
A dew point depression measuring device comprising:
- a test chamber with conrollable volume,
- first means for introducing air into said chamber at near ambient temperature and pressure conditions,
- second means for opening and closing said test chamber to ambient atmospheric conditions,
- third means for abruptly expanding said test chmaber in volume after said test chamber is sealed from said atmosphere by said second means,
- fourth means for detecting formation of ice or water particles in the test chamber,
- and a microprocessor including:
- fifth means for recording test chamber volume at the time said fourth means detects said formation of ice or water particles, and
- sixth means for computing dew point based on ambient temperature and said recorded test chamber volume,
- whereby said test chamber is controlled in volume, and said second, third and fourth means are coordinated in operation by said microprocessor.
A method of accurately measuring dew point depression under high relative humidity conditions comprising a microprocessor to coordinate the steps of:
- (a) providing a valved test chamber of controllable volume,
- (b) introducing air to the test chamber at nearly ambient temperature and pressure conditions,
- (c) sealing the chamber,
- (d) abruptly increasing the volume of said chamber,
- (e) detecting the formation of ice or water particles,
- (f) recording the volume of said chamber at which said water or ice particles are formed, and
- (g) calculating, from said recorded volume of said chamber, the dew point depression.
Dependencies are inferred from the claim text.