How to choose thermocouple or temperature instrument?
 
Speaking of the thermocouple or temperature instrument, I believe that we are not strange, with its superior performance, thermocouple or temperature instrument has been widely used in industrial production measurement, how do we choose? The following is an introduction from several aspects:

(1) if the temperature of the measured object changes with time, can the lag of the temperature measuring element adapt to the temperature measurement requirements?
(2) whether the temperature measuring element is of appropriate size.
(3) the size and accuracy requirements of the temperature measurement range.
(4) whether the environmental conditions of the measured object have damage to the temperature measuring element.
(5) whether the temperature of the measured object needs to be recorded, alarm and automatic control, and whether it needs to be measured and transmitted from a distance.

The selection of thermocouple or temperature instrument is mainly based on the measurement range.When the measurement range is expected to be within the total range, platinum resistance sensor can be used.A narrow range generally requires the sensor to have a fairly high base resistance in order to obtain a large enough change in resistance.Thermistors provide enough resistance variation to make these sensors ideal for a narrow range of measurements.More applicable if the measurement range is fairly large.It is best to include the freezing point in this range, because the index table is based on this temperature.The linearity of the known range of sensors can also be used as an additional condition for selecting sensors.Response time is usually expressed in terms of time constant, which is another basic basis for selecting sensors.The time constant is less important when monitoring the temperature in the tank.However, when the temperature in the vibration tube must be measured during use, the time constant becomes the determining factor in the selection of the sensor.