A High-Quality Platinum Resistance Thermometer to 661°C

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A High-Quality Platinum Resistance Thermometer to 661°C (85.57 KB)

A new high quality 25-ohm platinum resistance thermometer with an inconel protection sheath was developed. The thermometer adopts SPRT design techniques and meets all of the requirements of the ITS-90. It is more durable and affordable than typical SPRTs.

The structure and design of the thermometer are briefly discussed in this paper. The test results of a group of thermometers are presented. The tests included long-term and short-term stability, thermal cycling, thermal hysteresis, insulation resistance and W(Ga) value. The test results show the thermometer to be an excellent secondary standard for a temperature laboratory in the range from –200°C to 661°C.