Thermocouple insulation problems _ instrument

First of all, its positive and negative level generally separated, have a plenty of in the ceramic tube is separated again! Thermocouple for temperature measurement accuracy long take a temperature compensation method, is to find a way to ensure the temperature measuring end has been a constant temperature constant, neither let it is affected by temperature environment. Moreover, thermocouple is through two kinds of metal wire electronic flow to test temperature, metal wire winding copper wire must surely have after the happening of the electromagnetic induction phenomenon, so look, to measure the temperature of the numerical error is for sure! Thermocouple of high temperature insulation problem for thermocouple wire insulation protection, relatively low temperature with enameled wire under 200 degrees, and a polymer material 200 degrees, at up to 600 - 800 ℃ have that kind of stainless steel are directly related to the high temperature alloy alive inside the thermocouple as cable material coated, thermocouple integrated structure of direct powder magnesium oxide powder insulation, the metal coating lines smaller diameter can be less than 0. 5mm。 Thermocouple problems of several kinds of solutions to a problem of high temperature insulation, carried out in accordance with the instrument wiring diagram wiring right after electrify, first instrument display instrument of thermocouple indexing number, and then display instrument range limits, and measuring instrument discharge of digital tube display set temperature, the digital tube display on the meter measuring temperature. If digital tube display on the meter is not the temperature of the heating element, which shows the 'OVER', '0000' or '000', etc, that instrument malfunction, input parts should be done the following test: ( 1) The thermocouple from the meter thermocouple input to be removed, then the instrument with any wire thermocouple input terminal short circuit. On the electricity, instrument digital tube display value approximately at room temperature, thermocouple internal connection open circuit, the same type thermocouple should be changed. If still the status of the said above that instrument in the process of transportation, the input end of the instrument is damaged, to change the instrument. （ 2) The above fault instrument of thermocouple down, switch to run next to normal the same degree, access to the instrument of thermocouple, after electrify, the original fault instrument digital tube display on the heating element temperature, thermocouple internal connection open circuit, replace the same type thermocouple. If still the status of the said above that instrument in the process of transportation, the input end of the instrument is damaged, to replace the instrument. （ 3) The defective thermocouple removed from the instrument, measured with a multimeter in ohms ( R） * 1 file, use multimeter thermocouple at both ends, two table stick to test if the multimeter display on resistance value is very big, thermocouple internal connection open circuit, replace the same type thermocouple. Or have a certain value, the instrument input has a problem, should replace the instrument. （ 4) According to the instrument wiring diagram wiring is correct, if the instrument after electrify, digital tube display meter race such as negative phenomenon, illustrate access instrument thermocouple '+' and '- 'Wrong. Just need to change. （ 5) Wiring correct instrument at run time, the temperature of the instrument on the digital tube display and the actual measurement of the temperature difference of 40 degrees to 70 degrees. Even bigger difference, the instrument of indexing, and thermocouple dividing, make a mistake. By thermocouple indexing, B, S, K, E, etc. The temperature of the thermocouple and the millivolt ( MV） The value of the corresponding relation, under the condition of same temperature, the millivolt values ( MV） B the minimum degree, S degree, small, K index number is larger, E index number is larger, discriminant according to this principle.