高精度金-铂热电偶的制作和热电稳定性研究

金-铂热电偶是采用纯金和纯铂电极制成,长期使用过程中是否能够保持温度与热电势关系稳定是其准确测温的关键.首先,对热电极丝材进行剪切、清洗、退火并焊接组装成热电偶;然后,再对制作成的热电偶进行退火实验,热电偶在其使用上限965℃附近累计退火时间700 h,在银凝固点的稳定性达到±0.02℃.在制造热电偶过程中,采取了传统...

The Research on Construction the High Precision Au/Pt Thermocouple and its Stability of Thermoelectric Character

The stability of thermo-electric character in long term application of Au/Pt thermocouple, which is fabricated by a pure golden wire and a platinum wire, is a key to high accurate performance to in temperature measurement.Firstly, the thermo-elements were cut, cleaned, annealed, welded. Then, the thermo-elements were assembled to the thermocouples and were tested. The stability of whole thermocouples was proved within ±0.02℃ at Ag freezing point calibration, after ageing time of thermocouples was summed up to about 700h at temperature up to 965℃.The thermocouple measurement junction was constructed in three different ways: traditional type, mini-coil type and U shape type, the experiment results showed that the short-term stability is better for mini-coil type compare to U shape type applied to thermocouple measurement junction connection.