Definition
A monochrome infrared temperature measuring gun is a non-contact temperature measuring instrument that detects the radiation energy of a specific infrared band on the surface of a target object and converts it into a temperature reading according to the laws of radiation. It belongs to a type of radiation thermometer and is named for its usual measurements in a single narrow infrared band. This equipment is widely used in industrial process monitoring, equipment maintenance, food safety, building testing, and scientific research experiments, and is suitable for occasions where fast and safe measurement of the surface temperature of objects is required.
Principle
The monochrome infrared thermometer works based on Planck's law of black-body radiation. Any object with a temperature above absolute zero will radiate electromagnetic waves outward, and its radiation energy is related to the wavelength and surface temperature of the object. The optical system of the thermometer gun collects the infrared radiation emitted by the target surface and focuses it onto the infrared detector. The detector converts the radiated energy into an electrical signal, which is amplified and processed by a circuit, and then converts the signal strength into the corresponding temperature value according to the simplified form of Stephen-Boltzmann's law through a built-in algorithm. Its basic relationship can be expressed as:
V = ε·σ· T4
Where V represents the radiation signal received by the detector, ε is the emissivity of the target surface, σ is the Stephen-Boltzmann constant, and T is the absolute temperature of the target. The instrument compensates for differences in radiation characteristics on the surface of different materials by ε preset or adjustable emissivity parameters, thereby estimating the surface temperature.
Measurement method
When measuring with a monochrome infrared thermometer, follow the prescriptive steps to ensure data reliability. First, the correct emissivity value should be set on the instrument according to the material of the object being measured. The emissivity of common materials can be referred to the relevant standards or materials manuals. Secondly, it should be ensured that the optical field of view of the temperature measuring gun completely covers the target area being measured, and the target size is usually required to be larger than the spot size calibrated by the instrument. During measurement, it is necessary to keep the gun body stable, perpendicular to the surface to be measured, and avoid the presence of interfering media such as steam and dust in the measurement environment. For highly reflective surfaces, the surface emission characteristics can be temporarily changed by applying temperature tape or matte coating. It is recommended to read and record the average multiple times for each measurement to reduce random error.
Influencing factors
The measurement accuracy of a monochrome infrared temperature gun is affected by a variety of factors. The emissivity of the target surface is the most critical parameter, and inaccurate settings can lead to significant system errors. Environmental factors such as drastic changes in ambient temperature, suspended particles in the air, or water vapor can absorb or scatter infrared radiation. It is important to note that the relationship between the measurement distance and the spot size is that an increase in distance will lead to an increase in the actual measurement area and may include non-target objects. The cleanliness and roughness of the measured surface also affect the radiation characteristics. In addition, background thermal radiation, especially when the target temperature is small compared to the ambient temperature, can cause interference. The response time, spectral response range, and long-term stability of the instrument itself are also technical parameters that need to be considered.
Application:
Monochrome infrared temperature guns play a role in experiments and detections in multiple industries. In the electronics manufacturing industry, it is used to detect the operating temperature rise of circuit board components and transformers. In food processing, the surface temperature of baking and sterilization processes is monitored. In the Building Materials Laboratory, evaluate the properties of insulation materials or test thermal bridges for building envelopes. In the machinery and energy industry, it is used to check the temperature distribution of motor bearings, transmission line joints, boiler walls. In scientific research experiments, it can be used to observe the surface temperature field of chemical reaction processes or physical changes. Its non-contact, fast response characteristics make it suitable for temperature measurement on moving objects, charged objects or surfaces that are not easily touched.
Selection
Choosing a suitable monochrome infrared temperature measuring gun requires comprehensive consideration of measurement needs and technical parameters. First, clarify the temperature measurement range and accuracy requirements. Secondly, focus on optical resolution, which is the distance factor ratio, which determines the minimum target size that can be accurately measured at a specific distance. The adjustable range and adjustment method of emissivity should meet the requirements of the material to be tested. Response time is important for dynamic process measurement. Environmental conditions need to be considered, such as whether dust and water resistance is required. The instrument's data output functions, such as whether it has an analog output or a digital interface for recording, can be selected according to the system integration needs. In addition, ergonomics, display clarity and battery life also affect the user experience. It is recommended to refer to the performance requirements of infrared thermometers in specific application scenarios in relevant national or international standards, and verify them in combination with actual tests.