The quartz thermometer is a high-precision, high accuracy temperature sensor. It measures temperature by measuring the frequency of a quartz crystal oscillator. The oscillator contains a specially cut crystal that results in a linear temperature coefficient of frequency, so the measurement of the temperature is essentially reduced to measurement of the oscillator frequency. Resolutions of .0001 °C, and accuracy of .02 °C from 0-100 °C are achievable. The high linearity makes it possible to achieve high accuracy over an important temperature range that contains only one convenient temperature reference point for calibration, the

triple point of water Water () is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "univer ...

. Introduced by Hewlett-Packard in 1965, the successor company,

Agilent Agilent Technologies, Inc. is an American life sciences company that provides instruments, software, services, and consumables for the entire laboratory workflow. Its global headquarters is located in Santa Clara, California. Agilent was establi ...

, has discontinued the Model 2804A Quartz Thermometer. Other manufacturers make nearly linear-in-temperature quartz crystals that may be used to construct thermometers of similar performance.

References

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original announcement2804A Quartz Thermometer discontinued
- last version of the manual, available here, is dated 1986
Quartz temperature sensors
- linear crystals for making thermometers Thermometers