Industrial thermocouple release time: the correct way of cleaning - 2019 06 - 03 viewed: zero

Thermocouple is the purpose of cleaning out the surface contamination, improve its thermal coupling properties, extend the life of the thermocouple. After using a period because, thermocouple, its thermoelectric properties change, especially in high temperature, corrosion aerosols of board and special measurement ( Such as high speed, high pressure, high temperature molten metal and surface temperature measurement, etc. ) , the effect is more serious when the thermocouple thermoelectric properties change in excess of the prescribed scope, the temperature of the thermocouple instructions and distortion, which will influence the process of temperature control and the quality of our products and caused serious damage to the product is unqualified and heating equipment. So, you need to clean thermocouple. 1. Sodium borate used cleaning thermocouple sodium borate cleaning after washing. First the thermocouple wire electrode on annealing on platinum rhodium, and then to adjust current, make very hot thermocouple to 1100 ℃. With massive boric acid sodium touch the hot electrode, boric acid solution along the electrode of the water, 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, thoroughly remove boric acid salt. Sodium borate clear purpose is mainly to clean off the insoluble in hydrochloric acid and metal oxide. Because the boron sodium in high temperature melting and attached to the thermocouple hot metal impurity on the electrode and metal oxide generated molten boron glass, postpone electrode slipping away, reach the purpose of clearing the outer electrode contamination. 2. Annealing annealing is to eliminate internal stress in the electrode, improve thermocouple phase stability of thermocouple. Through proper annealing temperature and annealing time, can achieve the purpose of prayer. Two ways: usually annealing electricity annealing, hang the thermocouple annealing furnace annealing on the ark of the platinum wire hook, two electrodes of the Angle is about 30 °, slowly adjust current, make the hot electrode temperature of 1100 ℃, ( 0. 5 mm diameter of about 1. 5 a current) At this temperature thermal insulation for an hour, gradually reduce the current. Main electrode by annealing the longitudinal heated evenly, and attached to the electrode surface of low melting material sufficiently volatile.