Thermocouple measuring deviation of big reason?

Thermocouple measuring deviation of big reason? In the aluminium alloy cooling experiment, in order to measure the temperature variation curves of aluminous liquid during the cooling process, pull out a thermocouple in the aluminum liquid, in the process of aluminium liquid cooling and the liquid aluminum electromagnetic stirring. A once in a while, then to another thermocouple in liquid aluminum, the consequences found that two thermocouple readings are about 30 ~ 40 degrees. It makes me feel very strange, because ordinary, thermocouple bias is plus or minus 1%, even if a in favour, an under bias, reading the difference will not greater than 15 degrees.

the insertion order is: to pull out after the thermocouple temperature is high. Second, electromagnetic stirring not heating effect. Third, the models is armoured thermocouple k type thermocouple.

the above Issue ( The problem) Important first to understand, first pull out the thermocouple temperature high or pull out after the high temperature? Electromagnetic stirring had no heating effect? If have, that is, thermocouple by electromagnetic influence, try without electromagnetic stirring out under the condition of thermocouple http://www. wuxiyibiao。 com/。