GB/T 24247-2009Calibration and usage of ionization chamber systems for assay of radionuclides (English PDF)

Foreword

This Standard modifies and adopts IEC 61145:1992 Calibration and Usage of

Ionization Chamber Systems for Assay of Radionuclides (English version).

In comparison with IEC 61145:1992, this Standard has following differences:

---The definition of "accuracy" is modified; the index is modified from 10% to 5%,

and calculated in accordance with the formula of measurement error (see

Chapter 1, 3.1 and 4.6.1);

---reproducible is translated as "repeatable"; "repeatability" is modified from 5% to

2%; the formula of calculated by relative standard deviation is added (see

Chapter 1 and 4.6.2);

---The foreword and introduction part of IEC 61145 are deleted; the description of

"system" in the introduction part is brought into Chapter 1 "Scope";

---In "Normative References", Chinese national standards are used to replace IEC

standards quoted in IEC 61145 (Chapter 2);

---In "Terms and Definitions" in Chapter 3, "Uncertainty of Measurement" (3.2) and

"Repeatability (of results of measurements)" (3.3) are added; "shall" and

"should" are deleted;

---Two typical representatives of radionuclide source are added (131I, 60Co); the

calibrated energy range is expanded (4.3.3);

---The title of Chapter 5 is modified from "Error Source" into "Uncertainty

Component"; two components of instrument, "inherent error" and "repeatability"

are added;

---The title of Chapter 6 is modified from "Prompts" into "Main Factors Causing

Measurement Differences".

This Standard as proposed by China National Nuclear Corporation.

This Standard shall be under the jurisdiction of National Technical Committee on

Nuclear Instruments of Standardization Administration of China.

The drafting organizations of this Standard: Shenzhen Academy of Metrology & Quality

Inspection; Nuclear Industry Standardization Institute.

1 Scope

This Standard specifies the quantitative technique for the determination of

radionuclides' activity using various ionization chambers that are currently available.

The application of this Standard is limited to instruments that contain well-type

ionization chambers as detectors. It is a composite system that includes an ionization

chamber and an appropriate circuit in overall connection to it that converts the current

in the ionization chamber into a reading in the unit of activity.

This Standard provides methods to obtain measurement whose accuracy does not

exceed ± 6% and whose repeatability is not more than 2% (generally for radionuclides

larger than 3.7 x 106 Bq (100 µCi)).

2 Normative References

Through the reference in this Standard, the clauses of the following documents

become clauses of this Standard. In terms of references with a specified date, all the

subsequent modification sheets (excluding the corrected content) or revised versions

are not applicable to this Part. However, the various parties that reach an agreement

in accordance with this Part are encouraged to explore the possibility of adopting the

latest version of these documents. In terms of references without a specified date, the

latest version is applicable to this Part.

GB/T 4960.6-2008 Glossary of Terms for Nuclear Science and Technology - Part 6:

Nuclear Instrumentation

GB/T 4078-2008 Dimension of Sample Planchets, Vials and Test Tubes for

Radioactivity Measurement

3 Terms and Definitions

What is defined in GB/T 4960.6-2008, and the following terms and definitions are

applicable to this Standard.