Explanation of distance coefficient of infrared thermometer
The distance coefficient is determined by the ratio of D: S, which is the ratio of the distance D between the thermometer probe and the target to the diameter of the measured target. If the thermometer must be installed away from the target due to environmental conditions, and to measure small targets, a high optical resolution thermometer should be selected.
The higher the optical resolution, i.e. increasing the D: S ratio, the higher the cost of the thermometer. The Raytek infrared thermometer D: S ranges from 2:1 (low distance coefficient) to over 300:1 (high distance coefficient). If the thermometer is far from the target and the target is small, a thermometer with a high distance coefficient should be selected. The capacitance and inductance tester has the characteristics of small measurement workload, fast and simple, stable performance, accurate measurement, and high fault detection rate. It can also be used for measuring electrical equipment such as CVTs and lightning arresters.
For a fixed focal length thermometer, the focal point of the optical system is a small spot, and the spot near and far from the focal point will increase, resulting in two distance coefficients. Therefore, in order to accurately measure temperature at distances close to and far from the focal point, the size of the measured target should be greater than the size of the spot at the focal point; The zoom thermometer has a minimum focus position that can be adjusted based on the distance to the target. Increasing D: S reduces the received energy. Without increasing the receiving aperture, it is difficult to increase the distance coefficient D: S, which increases the instrument cost.
The non-contact infrared thermometer consists of an optical system, a photodetector, a signal amplifier, signal processing, display output, and other components. An optical system gathers the infrared energy emitted by a target object, focuses it on a photodetector, and converts it into corresponding electrical signals. After being processed by a circuit, it is converted into a linear temperature signal value of the measured target for further signal processing and control.
