Doza RPOGRESS-GAMMA Benutzerhandbuch - Seite 9

Blättern Sie online oder laden Sie pdf Benutzerhandbuch für Messgeräte Doza RPOGRESS-GAMMA herunter. Doza RPOGRESS-GAMMA 14 Seiten. Spectrometric complex for measurement of activity of alpha-, beta-, and gamma-emitting radionuclides

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2) In case that the difference between current and previously measured count rates in at least

one of the checked intervals exceeds the criterion preset in the software, it will warn the user about

change of the background spectrum.

If this is the case, eliminate the reason of increased background and perform two successive

measurements of background in accordance with step 1) above.

In case that during the last background measurements a high background warning will appear

again, results of the calibration should be considered negative with the wording «instability of the

background readings». It is recommended to dispatch gamma-spectrometer for repair.

3) Provided that background change warning does not appear upon completion of acquisition of

the background spectrum (3600 seconds), record the results of background measurements in the

table 4.3.

Table 4.3 - Results of background measurements.

Measured background spectrum

Previously measured

background spectrum

4.5.3.3 Measurement of the working standard activity

1) Perform energy calibration in accordance with section 4.5.3.1 and record results in the

table 4.2.

2) Remove calibration source out of the detector unit and place working standard with

geometry «Marinelli beaker 1 L» instead.

3) Start acquisition of the spectrum in the activity measurement mode by selecting geometry

«Marinelli - 1 L».

Record in the table 4.4 values of the measured specific activity and uncertainty of measurement

results for each of the gamma-emitting radionuclide included in the working standard together with

reference activity of this standard indicated in the calibration certificate for the working standard (after

correction for decay).

Table 4.4 - Results of specific activity measurements of the working standard.

Radionuclide

4.5.4 Processing of the measurement results

1) Calculate the mean value

4.5.3.3).

2) Calculate relative measurement error of the working standard activity by the following

formula

where А

– specific activity of the working standard OISN indicated in the calibration standard

(after correction for decay), Bq/kg;

 - mean value of measured specific activity of the working standard, Bq/kg.

Measured specific

activity



FVKM.412131.002-03RE

Count rate in the energy intervals, cps

Uncertainty

of measured activity of the working standard OISN (see













100



Reference specific

activity

(4.1)