JPH0577036B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention uses a multi-channel wave height analyzer as a test device to visually determine the discrimination level of radiation measuring instruments such as scalers and rate meters. The present invention relates to a discrimination level setting device that can quickly and accurately set a discrimination level.

[Prior art and its problems] In order to accurately count and measure radiation, the discrimination level has conventionally been set using the following method. That is, as shown in FIG. 3, the level setter 6A of the discriminator 6 in the radiation measuring instrument 4 is varied in unit steps, and the counting circuit 7 measures the count value for each step. The counted values were plotted on a graph, the characteristics of the level setter 6A were determined from the graph, and the required discrimination level was set. Note that 1 is a radiation source, 2 is a radiation detector, and 3 is a radiation source.
is a preamplifier, 5 is a main amplifier, and 7 is a counting circuit.

In addition, the output signal value from the detector 2 was measured in advance with an oscilloscope, and based on the required value, a simulated signal was electrically inputted to set the discrimination level.

All of these setting methods require too much time to set the discrimination levels for a large number of measurement points, and the setting accuracy is extremely poor at about ±10%. There was a problem.

[Object of the Invention] In view of the above points, it is an object of the present invention to provide a discrimination level setting device that effectively solves the problems of the prior art, reduces setting time, and improves setting accuracy. With the goal.

[Summary of the Invention] In order to achieve the object as described above, the present invention includes a multi-channel wave height analyzer to which the discriminator output of a radiation measuring instrument is input as a gate signal, and the gate signal is a coincidence count or It is characterized in that the discrimination level is set image-wise by the number of channels of the radiation energy spectrum of the multi-channel pulse height analyzer by switching to non-coincident counting.

According to one embodiment of the present invention, the set value of the discrimination level of the multichannel pulse height analyzer can be output and stored numerically.

[Embodiments of the Invention] Next, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG.
The figure shows a radiation energy spectrum diagram based on FIG. 1, in which (A) shows the case where there is no gate signal, (B) shows the case where the gate signal is coincident, and (C) shows the case where the gate signal is non-coincident. In FIGS. 1 and 2, parts having the same functions as those in FIG. 3 are given the same reference numerals. The discrimination level setting device 100 includes a multichannel wave height analyzer 8 connected as a tester to the radiation measuring device 4 and a printer 9 connected to the analyzer 8.

With this configuration, the disc discriminator 6
When the discrimination level setter 6A provided in the controller is varied, the count value of the counting circuit 7 changes. Therefore, it is extremely important for radiation measurement to be able to identify where the discrimination level setting value is set on the radiation energy spectrum.
The output signal Do of is inputted to the multichannel pulse height analyzer 8 as a gate signal. On the other hand, the radiation energy spectrum Rs counted by the input signal Ip from the preamplifier 3 is displayed on the multichannel pulse height analyzer 8 as shown in FIG. 2A.
At this time, as shown in Fig. 2B and C, by switching the mode of the gate signal between simultaneous counting and non-simultaneous counting, the discrimination level DL can be clearly seen directly from the number of channels of this radiation energy spectrum Rs. can. Therefore, while looking directly at this discrimination level DL,
By operating the disc millinator setting device 6A, the disc elimination level DL can be set visually accurately and in a short time. According to the device of the present invention, the discrimination level setting accuracy is less than ±1%, and the time required for setting is reduced to less than 1/30 compared to the conventional technology.

Note that the set discrimination level DL can be recorded numerically by a printer 9 connected to the multichannel pulse height analyzer 8.

[Effects of the Invention] As explained above, the present invention solves the problems of the prior art by applying a multichannel wave height analyzer as a test device when setting the discrimination level of a radiation measuring instrument. has been effectively resolved, making it possible to set the discrimination level visually and numerically while directly viewing the radiation energy spectrum, improving setting accuracy, shortening the setting time, and reducing the setting value. This has effects such as being output and recorded.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG.
The figure shows the radiation energy spectrum diagram in Figure 1.
3 is a block diagram of a conventional radiation measuring instrument. FIG. 3 is a block diagram of a conventional radiation measuring instrument. 4: Radiation measuring instrument, 5: Main amplifier, 6: Discriminator, 6A: Discrimination level setter, 7: Counting circuit, 8: Multi-channel wave height analyzer, 9: Printer, 100: Discrimination Level setting device, DL: discrimination level, Do: discrimination level output signal, Ip: input signal,
Rs: Radiation energy spectrum.

Claims (1)

[Scope of Claims] 1. A multi-channel wave height analyzer to which a discriminator output of a radiation measuring instrument is inputted as a gate signal, the mode of the gate signal being switched to coincident counting and non-coincident counting, and the multi-channel wave height analyzer A discrimination level setting device characterized in that a discrimination level is set graphically from the number of channels of a radiation energy spectrum of a pulse height analyzer. 2. In the discrimination level setting device according to claim 1, there is provided a disk capable of outputting and numerically storing the setting value of the discrimination level of the multi-channel wave height analyzer. Elimination level setting device.