JPH02248890A - Body surface monitor - Google Patents

Abstract

PURPOSE:To facilitate the checking of a scaler for normality by providing a reference pulse generator for testing within the scaler to integrate a reference pulse for testing inputted within a specified test time. CONSTITUTION:A measuring device 11 sets testing time periodically or properly once for several back ground measurements and switches a radiation detector 8 over to a pulse generator 10 to input a reference pulse for testing generated from the pulse generator 10 into an integrating counter 9A. After a specified time, the measuring device 11 stops the integration of the reference pulse from the generator 10 with the counter 9A to judge whether the number of pulses integrated is normal or not. This facilitates the checking of the scaler 9 for normality constantly and automatically and also enables discrimination even when a pulse signal of the radiation detector is abnormal.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is installed at the boundary between a radiation control area and a general area in a nuclear power plant or a radioactive material handling facility,
A body surface monitor that measures the amount of radioactive material adhering to the body surface of a subject who is leaving the room, especially a body surface monitor that can check the normality of a scaler that uses a pulse signal input from a radiation detector. I'm involved.

(Prior Art) FIG. 3 shows a schematic configuration diagram of a conventional body surface monitor. In the figure, the body surface monitor 1 mainly consists of the front detector housing section 2.
, a rear detector accommodating part 3, an exit side detector accommodating part 4, a head detector accommodating part 5, a bottom detector accommodating part 6, an entrance side detector accommodating part (not shown), etc. A radiation detector (not shown) is housed therein.

Furthermore, an operation instruction display section 7 for displaying an instruction on the operation state of the body surface monitor 1 is arranged in the front detector housing section 2 . The entrance side detector housing part and the exit side detector housing part 4, which are not shown, have functions as an entrance door and an exit door that can be opened and closed, respectively, and enter the room from the entrance side detector housing part side. After the degree of contamination by radioactive substances has been measured, exit is made from the exit side detector accommodating section 4 side.

Measurement of the degree of contamination by such radioactive substances is carried out using the h'
A scaler (not shown) inputs pulse signals from the i-ray detector at any time and sieves the pulse signals by 1f1.

(Problem to be Solved by the Invention) However, in order to test the normality of this scaler, if necessary, for example in the event of a scaler failure, a pulse generator is connected in place of the radiation detector, and this Decisions were made by examining a certain amount of pulse signals using a scaler. Therefore,
Testing was time-consuming, and it was not possible to constantly check whether the system was working properly during a song.

Furthermore, when the integrated value of the scaler is abnormal, there is a problem in that it is impossible to determine whether the problem is due to an abnormality in the radiation detector or the scaler.

In view of the above points, the present invention effectively solves the problems of the prior art and improves the normality of the scaler. It is an object of the present invention to provide a body surface monitor that allows easy identification and also makes it easy to determine whether an abnormality is occurring in a pHr14 ray detector or a scaler.

(Means for Solving the 8 Problems) In order to achieve such an object, the body surface monitor of the present invention includes a pulse generator installed in a scaler for generating a test reference pulse, and a test timer for the scaler. a measuring device that switches the pulse signal of the radiation detector to the test reference pulse and inputs data accumulated from the test reference pulse that is input to the scaler for a predetermined period of time to determine the normality of the scaler; Equipped with

(Function) With this technical means, the normality of the scaler can be constantly and automatically checked using data obtained by integrating the number of test reference pulses generated at fixed time intervals from the pulse generator installed in the scaler. It is possible. In addition, even when the pulse signal of the radiation detector is abnormal, by integrating the number of pulses of the pulse generator and confirming the normality of the scaler, it is possible to detect the pulse signal of the radiation detector rather than the abnormality of the scaler. It is determined that there is an abnormality.

(Example) Next, an example of the present invention will be described in detail based on the drawings.

FIG. 1 shows a schematic configuration diagram of an embodiment of the present invention. In FIG. 2, 8 is a radiation detector, 9 and 9A are a scaler and an integration counter, 10 is a pulse generator housed in the scaler 9, and 11 is a Measurement vtt! ! Reference numerals f and 12 are changeover switches that are provided in the scaler 9 and can be switched freely by the changeover signal output from the measurement Vi1M11. Radiation detector 8
The pulse signals inputted to the scaler 9 at any time are multiplied by the integration counter 9A at regular intervals to check for radioactive contamination.

By the way, when the radiation detector 8 is not detecting a specific object to be measured, for example at night when background measurement is being performed, the measuring device 11 sets the test time once every several background measurements. Set regularly or as appropriate,
The radiation detector 8 is switched to the pulse generator 10, and the test reference pulse generated by the pulse generator 10 is input to the integration counter 9A. After a predetermined time, the measurement wave [11 is
Stop the integration of the reference pulses from the pulse generator 10 by the integration counter 9A, read out the m brightness data a, and compare it with the normal integration value of the reference pulses to determine that the integrated number of pulses is normal. Decide whether or not.

Next, FIG. 2 is a flowchart of a scaler test of the body surface monitor shown in FIG. In the figure, the A system corresponds to the test of the scaler 9, and the 8 systems correspond to the background measurement. The measuring device 11 determines whether it is the scaler test time (step S1), and if it is the test time, switches from the pulse signal of the radiation detector 8 to the data (test reference pulse) input of the pulse generator 10 ( Step 82). This test time is arbitrarily selected. When the test time has elapsed, the integration of the reference pulses is stopped (step 83), and the integrated data of the reference pulses by the integration counter 9A is input to the measuring device 11, and the data is checked (step 84). As a result, W4
If there is an abnormality in the calculation data (step S5), the abnormality is displayed (step 86), and if there is no abnormality, the system moves to the B system and measures the background until the next scaler test time. Note that if the test time has not elapsed (step S1), data input to the pulse generator 10 is continued until the test time is reached.

In the background measurement of system B, the data of the pulse generator 10 is switched to the data input of the radiation detector 8 (step 87), and when the measurement time elapses, the integration of the detector output is stopped (step S8). , this integrated data is input to the scaler 9 (step S9). If the measurement time has not elapsed, background measurement is continued based on data input from the radiation detector 8.

(Effects of the Invention) As described above, according to the present invention, the body surface monitor includes a pulse generator provided in a scaler that generates a test reference pulse, and a pulse generator that sets the test time of the scaler to detect radiation. After switching the pulse signal of the device to the test reference pulse and inputting it to the scaler for a predetermined period of time to integrate the pulses, the test reference pulse signal is changed to the test reference pulse. The problems of the prior art are effectively solved by providing a measuring device that reads out the A brightness data and determines the normality of the scaler. By calculating the number of reference pulses by 8N, check the normality of the scaler! ? In addition, even when the pulse signal of the radiation detector is abnormal, if the normality of the scaler is confirmed by integrating the number of pulses of the pulse generator, the scaler can be checked automatically. This has the effect of determining that it is not an abnormality but an abnormality in the radiation detector.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG.
FIG. 3 is a flowchart of a scaler test of a body surface monitor shown in the figure, and FIG. 3 is a schematic configuration diagram of a conventional body surface monitor. 8... Radiation detector, 9... Scaler, 10... Pulse generator, 11... Measurement 8W1. 12... Selector switch. Seki Seki

Claims (1)

[Claims] 1) A radiation detector that detects radioactive contamination on the surface of the human body;
This body surface monitor includes a scaler that integrates pulse signals output from the radiation detector for a predetermined period of time, and a pulse generator that is installed in the scaler and generates a test reference pulse, and a pulse generator that sets the test time of the scaler and and a measuring device for determining the normality of the scaler by inputting data obtained by switching the pulse signal of the radiation detector to the test reference pulse and integrating the test reference pulse inputted to the scaler for a predetermined period of time. A body surface monitor featuring: