Thermocouple is a temperature meter with two heterogeneous metal wires as the main part. Among the wires used by thermocouple, platinum-rhodium thermocouple wire is the most accurate to react and measure the external temperature. Pt-rh thermocouple is also called high-temperature precious metal thermocouple, which is because both metal materials of pt-rh belong to precious metal, and the manufacturing cost of pt-rh thermocouple is relatively high.
The pt-rh thermocouple is divided into single pt-rh thermocouple and double pt-rh thermocouple, and their main function is to obtain the temperature of the measured object. Pt-rh thermocouple is often used with equipment such as temperature transmitter, temperature regulator and display instrument to form automatic control system to directly measure and control the temperature in various production processes.
The platinum rhodium thermocouple wire is made from platinum rhodium alloy and the diameter of the thermocouple wire should be 0.5 mm. The chemical composition of positive thermocouple wire is 30% rhodium and 70% platinum, while the chemical composition of negative thermocouple wire is 6% rhodium, which is also the reason for the naming of platinum and rhodium thermocouple.
The advantage of pt-rh thermocouple is that it has a wide range, especially a relatively high temperature measurement area. Meanwhile, pt-rh thermocouple has a long service life, the highest accuracy and the best stability. Another feature of the pt-rhodium thermocouple is that there is no need to use compensation wires. The pt-rhodium alloy has good oxidation resistance and can be used in oxidizing, inert and vacuum environment.
The pt-rh thermocouple also has some disadvantages. The main defects are low thermoelectric potential, low sensitivity and difficulty in achieving high mechanical strength at high temperature. Pt-rh thermocouple is a kind of thermocouple made with precious metal such as pt-rh. It has high production cost and is particularly sensitive to material pollution, so it needs high level of investment.
Stanford Advanced Materials supplies high-quality platinum-rhodium thermocouples products to meet our customers' R&D and production needs. Please visit http://www.samaterials.com for more information.