Pyrometry thermometers

In this range (100 to 550°) the domains of pyrometry and thermometry overlap somewhat, for high-temperature resistance thermometers and thermocouples generally classed as pyrometers are often used below 550°C. These instruments will not be... 

Equation (5) states that the total radiation of all wave lengths emitted by a black body is proportional to These two laws which form the basis of optical and radiation pyrometry respectively are in agreement with the temperature scale defined by the gas thermometer up to 1,550°C., the upper limit at which a gas thermometer has been used satisfactorily. Above this range to 2,500°C. the scales defined by these two laws have been found, experimentally, to be in mutual agreement, and it is believed that they correctly represent the thermodynamic scale for all temperatures. 

Recording Pyrometry.—The pyrometers which can be made to record automatically fall under the following classifications (1) Gas, saturated vapor, and liquid thermometers (2) resistance thermometers (3) thermoelectric pyrometers (4) radiation pyrometers. 

Temperature is undeniably the most important property for all calorimetric measurements, because it is the common denominator. Two different techniques for temperature measurements are used for pulse calorimetry contact thermometry (e.g. thermocouples) and radiation thermometry or pyrometry. Because pulse calorimetry is often used to handle and measure liquid materials, non-contact radiation thermometry is far more common in pulse-heating than contact thermometry. Other reasons for non-contact temperature measurement methods include the fast heating rates and temperature gradients (inertia of the thermocouples), difficulties mounting the contact thermometers (good thermal contact needed), and stray pick-up in the thermocouple signal because the sample is electrically self-heated. 

There is a general agreement that the application of fiber-optic thermometers is a reliable way to determine temperature under microwave conditions. However, according to some studies in which the reaction mixture was also monitored with a thermovision camera, it was shown that for the reactions in heterogeneous systems under microwave irradiation, the temperature measurement with a fiber-optic thermometer can lead to serious errors like pyrometry in particular, this is observed in those experiments that are planned without any attention being paid to temperature homogeneity of the reaction mixture. ... 

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