Common technical problems of infrared thermometer

I believe that many operators in the use of infrared thermometer have a variety of questions. Only by solving the questions can we work better. Nanjing Nuojin high speed analysis instrument factory has sorted out several common technical questions and answers of infrared thermometers. The free consultation hotline is 400-699-2086. Why use infrared thermometers?

Infrared thermometer adopts infrared technology, which can quickly and conveniently measure the surface temperature of objects. It does not need mechanical contact with the object to be measured and the temperature reading can be measured quickly. Just aim and press the trigger to read the temperature data on the LCD screen.

The infrared thermometer is light in weight, small in size and easy to use. It can reliably measure hot, dangerous or hard to touch objects without polluting or damaging the measured objects. The infrared thermometer can measure several readings per second, while the contact thermometer takes several minutes to measure each time.

2、 How does the infrared thermometer work?

Infrared thermometer receives invisible infrared energy from FA of various objects. Infrared radiation is a part of electromagnetic spectrum, including radio wave, microwave, visible light, ultraviolet, r-ray and X-ray. Infrared is located between visible light and radio waves. The infrared wavelength is usually expressed in micrometers, ranging from 0.7 μ m to 1000 μ M. in fact, the 0.7 μ M-14 μ M wave band is used for infrared thermometer.

3、 How to ensure the accuracy of infrared thermometer?

Infrared technology and its principle are understood as its accurate temperature measurement. When the temperature is measured by an infrared thermometer, the infrared energy emitted by the object FA 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.

There are several important factors that determine the accurate temperature measurement. The most important factors are fa emissivity, field of view, distance to the spot and the position of the spot.

FA emissivity, all objects will reflect, transmit and emit energy from FA. Only the energy emitted by FA can indicate the temperature of the object. When the infrared thermometer measures the surface temperature, the instrument can receive all three kinds of energy. Therefore, all infrared thermometers must be adjusted to read only the energy of FA emission. The measurement error is usually caused by the infrared energy reflected by other light sources. Some infrared thermometers can change the emissivity of FA, and the values of FA emissivity of various materials can be found in the published tables of FA emissivity. The other instruments are fixed with a fixed FA emissivity of 0.95. The FA emissivity value is the surface temperature of most organic materials, paints or oxidation surfaces, so it is necessary to use a kind of tape or flat black paint to compensate for the surface temperature. When the tape or paint reaches the same temperature as the base material, the temperature of the surface of the tape or paint is measured, which is the real temperature.

The optical system of the infrared thermometer collects energy from the circular measuring spot and focuses on the detector. The optical resolution is defined as the ratio of the distance from the infrared thermometer to the object and the size of the spot to be measured (D: s). The larger the ratio is, the better the resolution of the infrared thermometer is, and the smaller the spot size is. Laser aiming is only used to help aim at the measuring point. The improvement of infrared optics is to increase the near focus characteristic, which can provide accurate measurement for small target area and prevent the influence of background temperature.

Field of view to ensure that the target is larger than the spot size measured by the infrared thermometer. The smaller the target is, the closer it should be. When the accuracy is particularly important, it is necessary to ensure that the target is at least twice as large as the spot size.

4、 How to measure temperature with infrared thermometer?

In order to measure the temperature of the infrared thermometer, the infrared thermometer is aimed at the object to be measured, and the temperature data is read out on the LCD of the instrument according to the trigger, so as to ensure that the ratio of the distance to the spot size, and the field of view are arranged.

There are several important things to remember when using infrared thermometer:

1. Only the surface temperature is measured, but the internal temperature can not be measured by infrared thermometer.

2. Temperature measurement can not be carried out through glass. The glass has very special reflection and transmission characteristics, so accurate infrared temperature reading is not allowed. But the temperature can be measured by infrared window. It is better not to measure temperature on bright or polished metal surface (stainless steel, aluminum, etc.).

3. To locate the hot spot, the instrument aims at the target, and then scans the target up and down 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 the accurate temperature measurement.

5. Ambient temperature: if the infrared thermometer is suddenly exposed to the ambient temperature difference of 20 degrees or higher, the instrument is allowed to adjust to the new ambient temperature within 20 minutes.

5、 What are the most common applications of infrared thermometers?

1. Automotive Industry: diagnostic cylinders and heating / cooling systems.

2. HVAC: monitor air stratification, supply / return record, furnace performance.

3. Electrical: check for faulty transformers, electrical panels and connectors.

4. Food: scanning management, service and storage temperature.

5. Others: many engineering, base and transformation applications.

Nanjing Nuojin high speed analytical instrument factory

Technology Department