Inventory the advantages and disadvantages of non-contact temperature measuring instruments
Non contact temperature measuring instruments are designed based on the principle of thermal radiation of objects. When measuring, the temperature sensing element is not in direct contact with the tested object and is usually used to measure the temperature or surface temperature of high-temperature objects that move, rotate, or react quickly above 1000 ℃.
Its advantages are:
(1) Wide temperature measurement range (theoretically without upper limit), suitable for high-temperature measurement;
(2) During the temperature measurement process, it does not damage the temperature field of the measured object and does not affect the distribution of the original temperature field;
(3) Capable of measuring the temperature of moving objects;
(4) Small thermal inertia, short response time of the detector, fast temperature measurement response speed, about 2-3s, easy to achieve fast and dynamic temperature measurement. Under certain specific conditions, such as nuclear radiation fields, radiation thermometry can be accurately and reliably measured.
The disadvantages of non-contact temperature measuring instruments are:
(1) It cannot directly measure the true temperature of the tested object. To obtain the true temperature, emissivity correction is required, and emissivity is a parameter with complex influencing factors, which increases the difficulty of processing measurement results.
(2) Due to non-contact. The measurement of radiation thermometers is greatly influenced by the intermediate medium. Waiting is under industrial site conditions. The surrounding environment is relatively harsh, and the intermediate medium has a greater impact on the measurement results. In this regard, the selection of the wavelength range of the thermometer is very important.
(3) Due to the complex principle of radiation temperature measurement, the structure of the thermometer is complex and the price is high.
Non contact temperature measuring instruments mainly include radiation thermometers, fiber optic radiation thermometers, etc. The former is further divided into total radiation thermometers, brightness thermometers (optical pyrometers, photoelectric pyrometers), and colorimetric thermometers.
