Calibration - Fuji Electric NRF50 User Manual

9.3

Calibration

This section describes the calibration procedures for NRF50.
Expose NRF50 to the gamma-ray sources such as
A dose should be measured by placing the source at a certain distance (calibration distance)
from reference point of NRF50 so that true value of the dose is traceable to the National
Standard.
(1) Determination of a reference dose value (R
- Determine a reference dose value (R
a. Calculate R
source and reference point of NRF50 (calibration distance) and irradiation time.
b. Or the dose rate value at the reference point may be simply well-known by field
alibration/characterization. In this case, reference dose value (R
known dose rate value and irradiation time.
(2) Dose value (R
- Place the source such as
NRF50.
- Take the dose reading (R
from the reference source activity, the distance between the reference
0
) measurement
1
137
Cs and
) after irradiation which gives enough statistical stability.
1
Example of Geometrical Conditions
137
Cs and
)
0
) by the following method:
0
60
Co at the calibration distance from reference point of
60
Co.
) can be calculated by the
0
TN5A2293a
c
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