This will also apply to materials which are transparent to the eye, such as glass, gases and thin, clear plastics, but in addition, some of the IR energy will also pass through the object. did not measure satisfactorily in most circumstances, though they Ultrasonic Flow Meters  |   In temperature measurement this is most significant in the case of infrared opaque materials which have an inherently low emissivity. superseded. Of the energy absorbed by the object, a proportion will be re-emitted and part will be reflected internally. ADDRESS:No.286 Tongtai Road, Jinhu, Huai'an, Jiangsu Province, China. Flowmeters  |   The inner surface of such a sphere will have an emissivity of 0.998. Infrared thermometers for non-contact temperature measurement are highly developed sensors which have wide-spread application in industrial processing and research. being measured; and an ambient temperature compensation circuit This paper describes, in non-mathematical terms, the theory upon which the measurement technology is based, and how this is used to deal with the variety of application parameters which confront the intending user. It originates in the old practice of relating visible color to temperature, hence "color temperature." Despite these limitations, the ratio method works well in a number of well-established applications, and in others is the best, if not the most preferred solution. Thermocouple  |   Cartridge Heaters  |   There are a lot of different types, but the most common is a thermistor. As stated earlier, only IR wavelengths between 0.7 microns and 20 microns are used for practical temperature measurement. Kirchoff's Law When an object is at thermal equilibrium, the amount of absorption will equal the amount of emission. An infrared temperature sensor is a mature but dynamic technology that has and the preferred method for some others. Working of an Infrared Thermometer. The modern IRT is founded on this concept, but is more technologically sophisticated to widen the scope of its application. Tubular Heaters  |   Darling (1) in his book "Pyrometry," published in 1911. Careful installation means ensuring that the sensor is operated within its specified environmental limits, and that adequate measures are taken to keep the optics clean and free from obstructions. to an electrical signal; an emissivity adjustment to match the The emissivity of all materials does not change equally at two different wavelengths. Please verify your address. Those materials that do are called "Greybodies." A practical example of this is metallic paints which incorporate significant amounts of aluminum. Data Acquisition  |   the very small amounts of energy available at wavelengths beyond Given that emissivity plays such a vital role in obtaining accurate Thermowell  |   This paper describes, in non-mathematical terms, the theory upon which the measurement technology is based, and how this is used to deal with the variety of application parameters which confront the intending user. temperature data from infrared thermometers, it is not surprising Heaters  |   an indispensable technique for many temperature measurement applications, A factor in the selection process, when choosing a manufacturer, should be the availability of protective and installation accessories, and also the extent to which these accessories allow rapid removal and replacement of the sensor for maintenance. usually result, providing the equipment is carefully installed. Within this wave band, only frequencies of 0.7 microns to 20 microns are used for practical, everyday temperature measurement. Thermocouple Cable | Pressure Transmitters  |   If these guidelines are followed, the modern infrared thermometer will operate more reliably than thermocouples or resistance thermometers in many cases. It is an indispensable technique for many temperature measurement applications, and the preferred method for some others. parameters are properly considered, a successful application will to 1000 micrometers (microns). This is because the IR detectors currently available to industry are not sensitive enough to detect the very small amounts of energy available at wavelengths beyond 20 microns. It is unlikely that most IRT users will need to make use of the formulas, but a knowledge of them will provide an appreciation of the interdependency of certain variables, and serve to clarify the foregoing text. reliably than thermocouples or resistance thermometers in many