Understand infrared pyrometer in one second

(2)Wide measurement range: because it is non-contact temperature measurement, so the thermometer is not in a higher or lower temperature field, but in the normal temperature or the conditions allowed by the thermometer. Under normal circumstances can be measured from negative tens of degrees to more than three thousand degrees.

(3)Fast temperature measurement speed: that is, fast response time. As long as the infrared radiation of the target is received, the temperature can be fixed in a short time.

(4)High accuracy: infrared temperature measurement will not destroy the temperature distribution of the object itself as the contact temperature measurement, so the measurement accuracy is high. Infrared thermometers are usually accurate to within 1 degree.

(5) high sensitivity: as long as the object temperature has a small change, the radiation energy has a large change, easy to measure. Can be used for temperature measurement and micro temperature field

(3) Only measuring the external temperature of the object is not convenient to measure the temperature inside the object and when there are obstacles

Three, infrared thermometer performance indicators and selection

The performance indicators of infrared thermometer are: temperature range, display resolution, accuracy, working environment temperature range, repeatability, relative humidity, response time, power supply, response spectrum, size, maximum display, weight, emissivity, etc.

(1) Determine the temperature measurement range: the temperature measurement range is one of the most important performance indicators of the thermometer. Each type of thermometer has its own specific temperature range. Therefore, the user's measured temperature range must be considered accurate and comprehensive, neither too narrow, nor too wide. According to the Blackbody radiation law, the change in radiant energy due to temperature in the short wavelength of the spectrum will exceed that due to the emissivity error.

(2) Determine the target size: infrared thermometer can be divided into monochromatic thermometer and two-color thermometer (radiation colorimetric thermometer) according to the principle. For monochromatic thermometers, the area of the object to be measured should fill the field of view of the thermometer when the temperature is measured. It is recommended that the measured target size exceed 50% of the field of view. If the size of the target is smaller than the field of view, the background radiation energy will enter the visual signal branch of the thermometer and interfere with the temperature reading, resulting in errors. Conversely, if the target is larger than the thermometer's field of view, the thermometer is not affected by the background outside the measurement area. For a bicolor thermometer, the temperature is determined by the ratio of the radiated energy within two independent wavelength bands. Therefore, when the measured target is small, the field of view is not full, and there is smoke, dust, obstruction and attenuation of radiation energy in the measurement path, the measurement results will not have a significant impact. For small objects in motion or vibration, two-color thermometers are the best choice. This is due to the light's small diameter, flexibility, and ability to transmit radiation energy through curved, blocked, and folded channels.

(3)Determine the distance coefficient (optical resolution) : the distance coefficient is determined by the ratio of D: S, that is, the ratio of the distance between the probe of the thermometer and the target and the diameter of the measured target. If the thermometer must be located far away from the target due to environmental conditions and small targets are to be measured, a high optical resolution thermometer should be selected. The higher the optical resolution, the higher the D: S ratio, the higher the cost of the thermometer. If the thermometer is far from the target and the target is small, a thermometer with a high range coefficient should be selected. For a fixed focal length thermometer, the spot is the smallest at the focal point of the optical system, and the spot increases near and far from the focal point. There are two distance coefficients.

(4) Determine the wavelength range: the emissivity and surface characteristics of the target material determine the spectral wavelength of the thermometer for high reflectivity alloy materials, there are low or varying emissivity. In the high temperature region, the best wavelength for measuring metal materials is near infrared, 0.8 ~ 1.0μm can be selected. Other temperature zones can be selected 1.6μm,2.2μm and 3.9μm. Since some materials are transparent at certain wavelengths and infrared energy penetrates these materials, a special wavelength should be chosen for such materials.

(5)Determine the response time: the response time represents the response speed of the infrared thermometer to the temperature change measured, defined as the time required to reach 95% of the energy of the final reading, which is related to the time constant of the photodetector, signal processing circuit and display system. If the target is moving at a fast speed or the target is heated quickly, the fast response infrared thermometer should be selected, otherwise the signal response cannot be enough and the measurement accuracy will be reduced. However, not all applications require fast responsive infrared thermometers. For stationary or target thermal processes with thermal inertia, the response time of the thermometer can be relaxed.

(6)signal processing functions: given the discrete process (e.g., parts production) and continuous process is different, so the requirement of infrared thermometer has multiple signal processing function (e.g., peak and valley value be, average) available for selection, such as temperature measurement when the bottle on the conveyor belt, with peak holding, the temperature of the output signals to the controller. Otherwise the thermometer reads the lower temperature value between the bottles. With peak holding, set the thermometer response time to be slightly longer than the time interval between bottles so that at least one bottle is always being measured.
(7)Consideration of environmental conditions: the environmental conditions of the thermometer have a great impact on the measurement results, should be considered and properly resolved, otherwise it will affect the temperature accuracy and even cause damage. When the ambient temperature is high and there is dust, smoke and steam, you can choose the protective sleeve, water cooling, air cooling system, air purifier and other accessories provided by the manufacturer. These accessories effectively solve the environmental impact and protect the thermometer to achieve accurate temperature measurement. When determining attachments, standardized services should be required whenever possible to reduce installation costs.

(8)Infrared radiation thermometer calibration: infrared thermometer must be calibrated to make it correctly display the temperature of the measured target. If the temperature measuring instrument is out of tolerance during use, it must be returned to the manufacturer or maintenance center for re-calibration.

Four, the application of infrared thermometer

People use:

Infrared thermometer is not only used for daily body temperature measurement, but also suitable for rapid monitoring of body surface temperature in public places with large human flow. For example, infrared body temperature monitor, it has the advantages of non-contact temperature measurement, high accuracy, fast measurement speed, overtemperature voice alarm, especially suitable for entry and exit ports, ports, airports, docks, stations, offices, schools, theaters and other occasions.

Industrial external testing:

The industrial infrared thermometer measures the surface temperature of the object, and its light sensor radiates, reflects and transmits energy, and then the energy is collected and focused by the probe, and then the information is converted into readings displayed on the machine by other circuits. The laser lamp equipped with this machine is more effective in alignment with the object to be measured and improve the measurement accuracy.
Infrared thermometers have proved to be effective tools for detecting and diagnosing electronic equipment faults. Can save a lot of money, using infrared thermometer, you can diagnosis electronic connection issue and continuously by looking on the DC battery output filter joint of hot spots, to detect the function of the uninterrupted power supply (UPS), you can check the battery components and power panel terminals, switch gear or fuse connection, prevent energy consumption; Because loose connectors and combinations generate heat, infrared thermometers help identify insulation failures in loop interrupters. Or monitor the electronic compressor; Routine scanning of transformer hot spots can detect cracked windings and terminals.

Animal husbandry:
According to The Planck principle, the animal infrared non-contact thermometer can accurately display the individual body temperature of an animal by accurately measuring the body temperature of a specific part of the animal's body surface and correcting the difference between the body surface temperature and the actual temperature.