IR thermometers (pyrometers) are used to measure the temperature of objects at a distance. The principle of operation of this measuring device consists in measuring the heat radiation of the controlled object in the infrared range. The measurements of the device are loose objects, solids, and various liquids. Non-contact thermometers are most often designed for use in industry, in housing and in conducting energy audits. However, their application is possible in life and in Amateur practice.
the Basic parameters
The main specifications of thermometers include temperature measurement range. Even an inexpensive measuring instruments (e.g., models BALTECH TL-0212C) able to measure temperatures within the range -50…+1000 degrees. Pyrometer up to 1000 degrees able to cover quite a wide range of tasks.
The second important parameter of the contactless apparatus – the accuracy of the measurement. The pyrometers average price accuracy can be 1ºC. However, much depends on the temperature range. If it is 0 – 1000 degrees, the accuracy is 1.5 ºC. In the negative range (-50ºC 0ºC…) this figure will be below 3ºC.
The third important characteristic is the time of measurement. Modern pyrometer to 1000 degrees pretty quickly measures the temperature of the object, maximum per second.
The fourth characteristic – setting the emissivity. The surface structure of various materials at different emits energy and absorbs it. Therefore, when measuring temperature the thermometer on the brick, water, paper capacity of reflection will be 10-20%, reflecting (shiny) material (e.g., tungsten, gold, aluminum, metal) – 70-80%.
emissivity is the ratio of the two energies at a given temperature: the emitted object to the absolute emitted by the emitter. The emissivity in the range 0.1 – 1.0 (sometimes indicated as a percentage of 10% – 100%). If the pyrometer the option of setting this coefficient is missing for reflecting materials, the results will be quite dramatically different from the real temperature value. Therefore, before buying you should consult with a specialist. It will tell you whether your chosen model of the device for the required measurements or not.
Note that for user compiled a special table, which lists the emissivity of various materials. But in the expensive models, for the convenience of users, this data is already built into the phone’s memory.
For more information and a deeper study of methods of measuring temperature, we encourage you to sign up for training courses TOP-104.