Standard Platinum Resistance Thermometer

Standard Platinum Resistance Thermometer 

I. Description

The Standard Platinum Resistance Thermometer is used for compensation in standard temperature range of 13.8033k—961.8°C, and used as a standard when testing a variety of standard thermometers and high-precision thermometers. Within the above the temperature zone, it is also used directly for measuring the temperature of high-accuracy.

The Standard Platinum Resistance Thermometer measures the temperature according to the changeable regularity of the resistance temperature of the platinum.

In accordance with the regulations of ITS90, the T₉₀ is defined by the platinum thermometer when triple point (13.8033K) of the nitrogen balance reaches to the temperature range of silver freezing point. It is indexed by using the group of required defined freezing point and reference function as well as the deviation function of the temperature interpolation.

The above temperature zoning is divided into several and decided to work normally within the sub-temperature zone by various different forms of structure of thermometers. 

See the detailed thermometers in the table below:

Note: The Rtp of the above thermometers is 25±1.0Ω.The external diameter of quartz tubes is φ7±0.6mm.our factory also manufactures the platinum thermometer with the temperature zone of 83.8058K~660.323℃ as the working basic standard instrument.

II.                Use Information

1.      Before using, firstly, check the thermometer number to be consistent with the test certificate.

2.      When using, according to the lug logo of the thermometer wire terminal, connect the wire correctly. The lug① of the red wire is connected to the current positive terminal; the lug③ of  the yellow wire, to the current negative terminal; and the lug② of  the black wire, to the potential positive terminal; the lug④ of  the green wire, to the potential negative terminal.    

The following is the outline of the thermometer:

3.      The current should be 1MA according to the measuring of the temperature component of the thermometer.

4.      For matching the electrical measurement device of the thermometer for measuring temperature, the low resistance potentiometer of grade 1 and the standard coil resistance of grade 0.1 or the measuring precise temperature  bridge as well as the accessories should be used. The complete set of electrical measuring device should be guaranteed to have the sensitivity to distinguish the changing of one ten-thousandth Ohm.

5.      During the process of using, preservation and transportation, try to avoid the severe mechanical vibration of the thermometer.

6.      When using the first grade Standard Platinum Resistance Thermometer to test the temperature of the second grade Standard Platinum Resistance Thermometer, should follow the verification procedures approved by National Measurement Bureau.

7.      The regular test of the thermometer should be done stringently according to the relevant verification procedures and regulations .