Automatic compensation-type thermocouple metrological verification polarity extension connector

Abstract

The invention discloses an automatic compensation-type thermocouple metrological verification polarity extension connector which comprises a crocodile clip (1), a compensating conducting wire (2) and a copper conducting wire (3). One end of the compensating conducting wire (2) is connected to the crocodile clip (1) through positive and negative electrode guiding wires. The other end of the compensating conducting wire (2) is connected with the copper conducting wire (3) through positive and negative electrode outgoing wires. The other end of the copper conducting wire (3) is connected with two copper wiring forks (4). A free end (5) is arranged at the portion, close to the compensating conducting wire (2), of the copper conducting wire (3). The free end (5) is located in a freezing-point thermostat (10), and the temperature of the free end (5) is kept at 0 DEG C. The copper wiring forks (4) are used for being connected to a low-potential change-over switch (11) and a six half digital multimeter (12) to form a measurement circuit.

Description

technical field [0001] The invention relates to an automatic compensating thermocouple measurement verification polarity extension connector. Background technique [0002] For metrological verification of industrial thermocouples, including armored thermocouple cables, most of the connections between their free ends and test leads cannot be placed in a freezing point thermostat. For a long time, the cold junction temperature compensation method has been used, or the positive and negative poles of the compensation wires are used to weld the copper nickel-plated alligator clips, and the thermocouple leads are connected for verification. In the above two methods, the fluctuation of ambient temperature obviously affects the accuracy and reliability of the test results. Especially the connection and use of nickel-plated copper crocodile clips and ordinary compensation wires, although the connection is convenient during verification, the thermoelectric properties of nickel-plated...

AI Technical Summary

Problems solved by technology

In the above two methods, there is a problem that the fluctuation of ambient temperature obviously affects the accuracy and reliability of the verification results.

Especially the connection and use of nickel-plated copper crocodile clips and ordinary compensation wires, although the connection is convenient during verification, the thermoelectric properties of nickel-plated copper crocodile clips and thermocouples are completely different, and the error of ordinary compensation wires brings serious problems to the entire verification system. Considerable additional error and uncertainty

It is difficult to effectively guarantee the accuracy, repeatability and long-term reliability of metrological verification results

The problem is more obvious. For the same sample of armored thermocouple cable, the difference between the winter test results and the summer test results can be about 1.0°C. The reason for the above problems is the imperfect test device and method.

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