S type thermocouple method of maintenance

Platinum rhodium thermocouple is also called the s type thermocouple, the thermocouple is arguably China's industrialization and a very great invention, for we have brought huge profits, platinum rhodium thermocouple with high accuracy, high temperature resistant, temperature and other characteristics. Therefore platinum-rhodium thermocouple is also called high temperature metal thermocouple, suitable for all kinds of high temperature circumstance in the process of production, such as powder metallurgy, bright sintering furnace, such as smelting furnace temperature measurement of platinum-rhodium thermocouple used is very common.

so it is necessary to learn more about platinum rhodium thermocouple maintenance tips:

1) Pickling

using acid oxidation ability, high temperature to remove organic matter on the surface of the precious metal platinum rhodium thermocouple and other impurities can be acid dissolution.

will be high temperature metal platinum-rhodium thermocouple in diameter circle about 80 mm in the beaker, import - 30% 50% ( According to the volume ratio) Chemical pure dilute hydrochloric acid ( Or dilute nitric acid) One hour, take out into a beaker, thoroughly with distilled water for a few times to remove the acid. The purpose of pickling was part cleaning electrode surface oxide and organic materials.

2） Sodium borate cleaning

used high temperature metal platinum-rhodium thermocouple sodium borate cleaning after acid pickling. First high temperature metal platinum-rhodium thermocouple electrode hangs on the platinum wire annealing on the ark, and then to adjust current, make very hot thermocouple to 1100 ° C. With block sodium borate hit a hot spot, who make the boric acid solution down along the electrode, slowly reduce current after cleaning, the last cut off the power and take footwall in 80 mm diameter circle into a beaker, several times with distilled water to boil, completely precipitate boric acid salt. Sodium borate clear purpose is mainly appeal insoluble in hydrochloric acid and metal oxide. Because of sodium borate in high temperature melting and attached to the high temperature metal platinum-rhodium thermocouple hot metal impurity on the electrode and metal oxide generated boron glass solutions, suitable hot electrode outflow, reach the purpose of clearing the outer electrode contamination.

3） Annealing

annealing is to eliminate internal stress in the electrode, improve the high temperature metal platinum-rhodium thermocouple phase to improve stability of precious metals platinum rhodium thermocouple. Through proper annealing temperature and annealing time, can achieve the purpose of prayer. Annealing generally has two methods:, electric annealing furnace annealing.