JPS6156926A - Compensating device of radiation detector - Google Patents

Abstract

PURPOSE:To make it possible to perform correct measurement all the time, by correcting the decrease in output in a region, where radiation energy, which is inputted to a radiation detector, is high. CONSTITUTION:Inputted radiation energy L is converted into electric signal by a radiation detector 1. The output is amplified by an amplifying means 2 with the temperature being compensated by a temperature compensating signal (a). In a region, where the inputted radiation energy L is high and can be reproduced, the output of the means 2 is corrected by a correcting means 3. Even though the emissitivity of a body to be measured is decreased, the correct measurement can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of the Invention The present invention relates to a compensation device for a radiation detector that detects infrared radiation energy from a measurement object and measures its temperature.

(2) There are various types of conventional radiation detectors such as 8i, Pb8, etc., but when the incident energy becomes high, as shown in Fig. 1 (■), the measurement is performed when the radiograph of the object is 1.

The output decreases and eventually reaches saturation, resulting in poor linearity. Furthermore, when the energy incident on the detector increases, the detector itself is heated, and the ideal output shown in FIG.

Conventionally, the actual output shown in Fig. 1 (■) was used as the detector characteristic, and a scale was provided.

Therefore, in measurements with a low emissivity t = 0.5, □, because no large radiant energy is incident on the detector.

The output decrease as described above does not occur, and the output is as shown in FIG. 1 (■). However, due to the characteristics of the scale, the output in Figure 1 (■) is correct because it is 1/2 of the output in Figure 1 (■), so an error occurs.(3) Purpose of the Invention SUMMARY OF THE INVENTION In view of one or more points, it is an object of the present invention to provide a compensation device for a radiation detector that allows accurate measurements at all times even when the radiation energy incident on the radiation detector is high.

(4) Principle/Summary of the Invention This invention corrects the actual output shown in Fig. 1 so that the incident energy of the crystallizer is high and the ideal output as shown in Fig. 1 is achieved in a reproducible region S. By doing so, even if the incident energy decreases and becomes as shown in Fig. 1, accurate measurements can be made over a wide range.

In other words, the present invention provides means for correcting a decrease in detector output in a reproducible region where the radiant energy incident on the radiation detector that receives radiant energy and converts it into an electrical signal is high. This is a compensation circuit for a radiation detector.

(5) Embodiment of the Invention FIG. 2 is an explanatory diagram showing an embodiment of the invention.

In the figure, 1 is a radiation detector that converts incident radiant energy into an electrical signal, 2 is an amplification means that temperature-compensates and amplifies the output of the radiation detector 1 using its temperature compensation signal, and 3 is an input of the radiation detector 1. This is a correction means that corrects the output shown in FIG. 1 (2) as shown in FIG. 1 (■) in a high energy and reproducible region.

In other words, in a region where the radiation energy incident on the radiation detector 1 is high and reproducible.

The output amplified by the amplifying means 2 of the radiation detector 1 is:

Because correction means 3 has determined the correct ideal output.

Correct measurements are always possible even if the emissivity of the measurement object decreases.
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FIG. 3 shows another embodiment of the invention, in which the same reference numerals as in FIG. 2 indicate the same components.

In this example, the A-D converter 4° ROM is used as the correction means.
Notes like! J5. Using DA converter 6.

The correction coefficients are stored in the memory 5 in advance.

Radiation detector 1. The output of the amplifying means 2 is converted into a digital signal by the A-D converter 4, and the memory 5 is converted into a digital signal according to this digital signal value.
The correction coefficient is read out from the DA converter 6 and multiplied by the output of the amplifying means 2 to obtain a correct corrected signal.

By the way, in order to determine the correction value, 1. For example, radiant energy from a blackbody furnace at a constant temperature is incident on the radiation detector 1, and 2.
Using meshes with various transmittances, find the relationship between transmittance and output as shown in Figure 4 ■, and from this, Figure 4 ■
Find the correction value that results in an output as shown in .

In addition, as shown in Figure 5 (■), the temperature-output characteristic when emissivity ε = 1.0 and the temperature-output characteristic when emissivity t = 0.5 as shown in Figure 5 Φ. seek.

The curve shown in Figure 5 (■) is doubled to obtain the ideal output, and the correction value is determined from the difference between the curve shown in Figure 5 (2) and the curve shown in Figure 5 (2).

(6) Effect of corner cutting As mentioned above, in this invention, the radiation energy incident on the radiation detector is large, and correction is performed in a reproducible region, so the measurement operating range (dynamic range) is It can be expanded, the influence of minute temperature changes of the detector itself can be reduced, and even if the emissivity of the measurement target varies, accurate measurement is always possible.

[Brief explanation of the drawing]

FIG. 1, FIG. 4, and FIG. 5 are explanatory diagrams of the present invention. FIGS. 2 and 3 are configuration explanatory diagrams showing one embodiment of the present invention.

Claims (1)

[Claims] 1. A radiation detector that receives radiant energy and converts it into an electrical signal, and corrects a decrease in the output of the radiation detector in a region where the radiant energy incident on the radiation detector is high and is reproducible. 1. A compensation device for a radiation detector, characterized in that it is provided with a compensation means.