A device and method for rapidly measuring surface infrared hemispheric emissivity

Abstract

The invention discloses a device and method for quickly measuring surface infrared hemispheric emissivity, which comprises an outer cylinder, an upper support plate and a lower support plate, a double-cavity main body is arranged in the outer cylinder, and the output shaft of a low-speed motor passes through the double-cavity main body The slender shaft in the middle is connected, and the upper end of the slender shaft is connected with a modulation plate; the double-cavity main body is symmetrical to the slender shaft, and there are two high-temperature thermal chambers with a large upper opening and a small lower opening, and a low-temperature thermal chamber. The base is fixed Holes are respectively opened at positions corresponding to the lower openings of the high-temperature thermal cavity and the low-temperature thermal cavity, and pyroelectric sensors are respectively arranged in the holes. Through the method of combining high and low temperature thermal cavity emission, mechanical modulation reflection, pyroelectric effect and lock-in amplification, it eliminates the influence of ordinary reflection method itself, the influence of environmental radiation and the shortcomings of not being suitable for high temperature measurement, and is suitable for field industry, etc. Online rapid measurement of emissivity in complex environments.

Description

technical field [0001] The invention relates to an emissivity measurement technology, in particular to a device and method for rapidly measuring the emissivity of a surface infrared hemisphere. Background technique [0002] Many emissivity measurements need to be done in the field or in harsh conditions. For example, in geological exploration, team members need to complete real-time measurements of soil emissivity to obtain important information such as temperature. Thermal emissivity requires a final verification locally at the launch site. In non-contact temperature measurement such as infrared thermal imaging cameras, emissivity is also one of the important factors affecting the accuracy of temperature measurement. Therefore, the portability, quickness and stability of the emissivity detector are very important. However, at present, the methods for measuring the surface emissivity of objects are mostly the steady-state method, which is generally completed in the laborat...

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Problems solved by technology

[0003] At present, measurement devices based on calorimetry generally use steady-state measurement, which takes a long time and requires high precision for various parameters such as temperature and heat capacity. Although the pulse heating transient calorimetry device of NIST in the United States has significantly improved the measurement accuracy and speed , but it can only be used to measure conductor materials

Although the measurement device based on the energy method can accurately measure the emissivity of the material in the spectral direction, it is also the main means of calibrating the emissivity, but due to the need for precision equipment such as light source and optical path, the cost is expensive and the structure is complicated, so it is not convenient for on-line measurement in field industry, etc.

However, the general measurement device based on the reflection method requires the temperature of the material to be tested to be much lower than the temperature of the reflective wall of the thermal cavity due to the influence of the radiation of the material itself. Accuracy is affected

The newly developed multi-wavelength method has fast measurement speed and no upper limit for temperature measurement, but there is no good algorithm suitable for all materials, and the accuracy still needs to be improved

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