Frequently asked questions and answers for infrared thermometers
1、 The relationship between the size of the temperature measurement target and the temperature measurement distance (concept of optical resolution)?
The effective diameter D of measurable targets varies at different distances, so it is important to pay attention to the target distance when measuring small targets. The distance coefficient K of an infrared thermometer is defined as the ratio of the distance L of the measured target to the diameter D of the measured target, i.e. K=L/D
It is the relationship between the size of the temperature measurement target and the temperature measurement distance
2、 How to choose the emissivity of the tested substance?
Infrared thermometers are generally based on blackbody (emissivity ε= 1.00) graduated, but in reality, the emissivity of substances is less than 1.00. Therefore, when measuring the true temperature of the target, the emissivity value must be set. The emissivity of substances can be obtained from the "Data on the emissivity of objects in radiation thermometry".
3、 How to measure targets in a strong light background?
If the measured target has a bright background light (especially when exposed to direct sunlight or strong lights), the accuracy of the measurement will be affected. Therefore, objects can be used to block the strong light of the direct target to eliminate background light interference.
4、 How to measure small targets?
Aiming and focusing
Aiming: The small black dots in the eyepiece are the temperature measurement points, and the black dots are aimed at the measured target
Focusing: The objective lens moves back and forth until the measured target is clear. If the diameter of the measured target is much larger than the small black dot, * * focusing can be omitted. Please refer to the manual for the specific method of focusing
When measuring small targets, in order to ensure measurement accuracy
The thermometer should be fixed on a tripod (optional accessory)
(2) Focusing is required, that is, use the small black spots in the eyepiece to aim at the target (the target should be full of small black spots), adjust the lens back and forth, and shake the eyes slightly. If there is no relative movement between the small black dots measured, focusing is completed
