Specific reasons caused thermocouple thermal response time is too long

Thermocouple, relatively cheap and high precision, and its relatively wide measuring range, so are widely used in many industries. But as in use process, interference by external factors, the performance and measuring will produce certain effect, such as response time.

in addition to the influence of external factors, thermocouple in the process of unceasing development, in order to adapt to different environment, the use of the type of thermocouple is not short in growth, and according to the American national standards institute ( ANSI) Convention, the larger letters indicate its composition. J type thermocouple, for example, by a metal conductor and a copper nickel alloy conductors. Thermocouple other types including B, E, K type thermocouple, N, R, S, and T. The following give you specific introduction of thermocouple thermal response time is too long.

the three major factors influencing the thermocouple response time:

a, the response time of the thermocouple and its structure and size. The hot electrode, protecting tube diameter is more coarse and wall more thick, then its inertia, the greater the making the interval of reaching stability state of thermocouple is longer, will also affect its response time.

2, thermocouple response time also along with the change of working condition is different, that is to say the same of the structure of the thermocouple, under the condition of different heat exchange, the response time is different.

3, the production of thermoelectric materials, heat conduction performance is also different. Such as metal protection tube compared with ceramic protection tube, the heat conduction performance is good, so the thermal inertia is small, and the interval of reaching stability state of thermocouple is short, short response time.