Working principle and technical questions and answers of infrared thermometer
1. Why use a non-contact infrared thermometer?
Non-contact infrared thermometers use infrared technology to quickly and easily measure the surface temperature of objects. Quickly obtain temperature readings without mechanical contact with the measured object. Just aim, press the trigger, and read the temperature data on the LCD display. Infrared thermometers are lightweight, compact, easy to use, and reliably measure hot, hazardous, or hard-to-reach objects without contaminating or damaging the object being measured. Infrared thermometers can take several readings per second, while contact thermometers take several minutes to measure per second.
2. How does the infrared thermometer work?
Infrared thermometers receive invisible infrared energy emitted by various objects themselves. Infrared radiation is part of the electromagnetic spectrum, which includes radio waves, microwaves, visible light, ultraviolet, R-rays and X-rays. Infrared is located between visible light and radio waves. Infrared wavelengths are often expressed in microns, and the wavelength range is 0.7 microns to 1000 microns. In fact, the 0.7 microns to 14 microns band is used for infrared thermometers.
3. How to ensure the temperature measurement accuracy of the infrared thermometer?
An undisputed understanding of infrared technology and its principles for its precise temperature measurement. When the temperature is measured by an infrared thermometer, the infrared energy emitted by the measured object is converted into an electrical signal on the detector through the optical system of the infrared thermometer, and the temperature reading of the signal is displayed. The most important factors are the emissivity, the field of view, the distance to the spot and the position of the spot. Emissivity, all objects reflect, transmit, and emit energy, and only the emitted energy gives an indication of the object's temperature. When an infrared thermometer measures surface temperature, the instrument receives all three types of energy. Therefore, all infrared thermometers must be tuned to read only emitted energy. Measurement errors are often caused by infrared energy reflected from other light sources. Some infrared thermometers can vary the emissivity, and emissivity values for various materials can be found in published emissivity tables. Other instruments were fixed with an emissivity preset of 0.95. This emissivity value is for the surface temperature of most organic materials, painted or oxidized surfaces, and is compensated by applying a tape or flat black paint to the surface being measured. When the tape or varnish reaches the same temperature as the base material, measure the temperature of the surface of the tape or varnish, which is its true temperature. The ratio of the distance to the spot, the optical system of the infrared thermometer collects energy from the circular measuring spot and focuses it on the detector, the optical resolution is defined as the ratio of the distance from the infrared thermometer to the object and the measured spot size (D :S). The larger the ratio, the better the resolution of the infrared thermometer and the smaller the measured spot size. Laser aiming, only to aid in aiming at the measuring point. The Zxin improvement of infrared optics is the addition of near-focus characteristics, which can provide accurate measurements on small target areas and also prevent the influence of background temperature. Field of view, make sure that the target is larger than the spot size of the infrared thermometer. The smaller the target, the closer it should be. When accuracy is critical, make sure the target is at least 2x the spot size.
4. How to measure temperature with infrared thermometer?
In order to measure the temperature of the infrared thermometer, point the infrared thermometer at the object to be measured, press the trigger to read the temperature data on the LCD of the instrument, and ensure that the ratio of the distance to the spot size and the field of view are arranged. There are a few important things to remember when using an infrared thermometer:
1. Only the surface temperature is measured, and the infrared thermometer cannot measure the internal temperature.
2. The temperature cannot be measured through the glass. The glass has very special reflection and transmission characteristics, which does not allow accurate infrared temperature readings. But the temperature can be measured through the infrared window. Infrared thermometers are best not used for temperature measurement on bright or polished metal surfaces (stainless steel, aluminum, etc.).
3. Locate the hot spot. To find the hot spot, the instrument aims at the target, and then scans up and down on the target until the hot spot is determined.
4. Pay attention to environmental conditions: steam, dust, smoke, etc. It blocks the optical system of the instrument and affects accurate temperature measurement.
5. Ambient temperature, if the infrared thermometer is suddenly exposed to an ambient temperature difference of 20 degrees or higher, allow the instrument to adjust to the new ambient temperature within 20 minutes.
