12-02-2013, 01:58 PM
Linear quartz thermometers
[attachment=50577]
INTRODUCTION
A thermometer is a device that measures temperature or temperature gradient using a variety of different principles.
The different types of thermometers are
Liquid-in-glass thermometer
Gas thermometer
Infrared thermometers
Bi-metallic stemmed thermometers
Thermocouples
Resistance thermometer
INTRODUCTION
It has long been recognized that the temperature dependence of quartz crystal resonators was a potential basis for the accurate measurement of temperature.
In practice, however, it has not previously been satisfactory to make wide-range temperature-measuring systems based on quartz resonators because of the large non-linearity in the temperature coefficient of frequency of available quartz wafers.
SENSOR CONSTRUCTION
Gold is deposited on electrodes on the surface of the quarter inch diameter quartz wafer. Each wafer is brazed to three small ribbons so that it can be placed in a transistor case.
The wafer case is hermetically sealed in a helium atmosphere which provides both a good heat conduction path and a passive atmosphere for long term resonator stability.
[attachment=50577]
INTRODUCTION
A thermometer is a device that measures temperature or temperature gradient using a variety of different principles.
The different types of thermometers are
Liquid-in-glass thermometer
Gas thermometer
Infrared thermometers
Bi-metallic stemmed thermometers
Thermocouples
Resistance thermometer
INTRODUCTION
It has long been recognized that the temperature dependence of quartz crystal resonators was a potential basis for the accurate measurement of temperature.
In practice, however, it has not previously been satisfactory to make wide-range temperature-measuring systems based on quartz resonators because of the large non-linearity in the temperature coefficient of frequency of available quartz wafers.
SENSOR CONSTRUCTION
Gold is deposited on electrodes on the surface of the quarter inch diameter quartz wafer. Each wafer is brazed to three small ribbons so that it can be placed in a transistor case.
The wafer case is hermetically sealed in a helium atmosphere which provides both a good heat conduction path and a passive atmosphere for long term resonator stability.