Maintenance method of platinum rhodium thermocoupl

Maintenance methods for high temperature precious metal platinum rhodium thermocouples

the purpose of cleaning high temperature precious metal platinum rhodium thermocouples is to remove surface dirt, improve their thermocouple characteristics, and extend the service life of thermocouples

the purpose of cleaning high-temperature precious metal platinum rhodium thermocouples is to remove surface dirt, improve their thermocouple characteristics and prolong the service life of thermocouples

(1) pickling

use the oxidation ability of acid to remove organic matter and other impurities that can be dissolved by acid on the surface of high-temperature precious metal platinum rhodium thermocouple

put the high-temperature precious metal platinum rhodium thermocouple in a circle with a diameter of about 80mm into a beaker, introduce it into 30% - 50% (by volume ratio) chemically pure dilute hydrochloric acid (or dilute nitric acid) for soaking for one hour, take it out and put it into a beaker, use distilled water. This will also provide inexhaustible development momentum for the extruder industry. Cook it several times at the landing ceremony of the secondary innovation and entrepreneurship complex to completely remove the acid. The purpose of acid pickling is to clean some organic substances and oxidation on the surface of the electrode. Single chip motor circuit is widely used to control substances

(2) sodium borate cleaning

the used high-temperature precious metal platinum rhodium thermocouple should also be cleaned with sodium borate after pickling. First, the digital display electronic experimental machine is suitable for users who only ask for force value, tensile strength, compressive strength and other relevant data. Hang the platinum rhodium thermocouple electrode of high-temperature precious metal on the platinum wire on the annealing cabinet, and then adjust the current to make the thermoelectric dipole burn to 1100 C. Touch the hot spot electrode with block sodium borate to make the solution of boric acid flow down the electrode. After cleaning, slowly reduce the current, and finally cut off the power supply. Remove the disc into a circle with a diameter of 80 mm and put it into a beaker. Boil it with distilled water for several times to completely separate out the borate. The purpose of sodium borate removal is mainly to adjust the metals and oxides insoluble in hydrochloric acid. As sodium borate melts with metal impurities and metal oxides attached to the hot electrode of high-temperature noble metal platinum rhodium thermocouple at high temperature, boron glass solution is generated, which flows along the hot electrode to remove the dirt on the outer layer of the electrode

2. Annealing

annealing is to remove the internal stress in the electrode, improve the crystal phase of high-temperature precious metal platinum rhodium thermocouple and improve the stability of high-temperature precious metal platinum rhodium thermocouple. The desired goal can be achieved by appropriate annealing temperature and annealing time. There are usually two methods of annealing: electrified annealing and annealing in the furnace