**3.2.2 Validation of methods and establishment of equivalence by key comparisons**

**Definition of the Key Comparisons, according to VIM***: Selected comparisons taken formally into account for the establishment of equivalence.* CCRI(II) may approve also supplementary comparisons, initiated by other organizations, to be used for establishment of equivalence: EURAMET, COOMET, IAEA, JRC-IRMM, etc. Relative methods may be used at this level, in order to extend the applicability of the CIPM-MRA, Annex C.

The Comparisons are of the categories:


*Type: "EURAMET.RI(II)-S5.Radionuclide".* These comparisons are deployed as Decay Data Evaluation Projects-DDEP. The first step of comparisons is similar to the CCRI(II)-K2. The second step consists of the measurement of the emission intensities for *x* and gamma-rays. IFIN-HH, RML is registered with: 169Yb; 65Zn; 124Sb.

*"IAEA-CCRI(II). Matrix content. Radionuclides".* These comparisons are organized within the frame of the International Atomic Energy Agency (IAEA) - Coordinated Research Projects

in figure 1. The equivalence is demonstrated only by the participation at international comparisons. IFIN-HH, RML, has participated at international comparisons since 1962. *The Key Comparison Data Base (KCDB) Annex B of the CIPM – MRA*, can be found at the address: http://kcdb.bipm.org/AppendixB/KCDB\_ApB\_search.asp. The participants in CIPM-MRA are the National Institutes of Metrology (NMIs), but for specialized metrology branches as the ionizing radiations, the participants can be the Designated Institutes. In Romania, according to the protocol concluded between BRML-INM and IFIN-HH it is established that IFIN-HH is designed as the owner of the primary activity (Becquerel) and derived quantities



Due to its scientific authority, IFIN-HH became also: Member of the International Committee for Radionuclide Metrology (ICRM) in 1980 and Member of the Consultative

**3.2.2 Validation of methods and establishment of equivalence by key comparisons Definition of the Key Comparisons, according to VIM***: Selected comparisons taken formally into account for the establishment of equivalence.* CCRI(II) may approve also supplementary comparisons, initiated by other organizations, to be used for establishment of equivalence: EURAMET, COOMET, IAEA, JRC-IRMM, etc. Relative methods may be used at this level, in



*Type: "EURAMET.RI(II)-S5.Radionuclide".* These comparisons are deployed as Decay Data Evaluation Projects-DDEP. The first step of comparisons is similar to the CCRI(II)-K2. The second step consists of the measurement of the emission intensities for *x* and gamma-rays.

*"IAEA-CCRI(II). Matrix content. Radionuclides".* These comparisons are organized within the frame of the International Atomic Energy Agency (IAEA) - Coordinated Research Projects

standard, with national and international responsibilities in the field:

order to extend the applicability of the CIPM-MRA, Annex C.

*A of the CIPM-MRA, List of signatories.* 

Committee Section II, CCRI(II), in 2004

The Comparisons are of the categories:

192Ir, 177Lu, 54Mn, 32P, 75Se, 89Sr, 204Tl, 65Zn.

IFIN-HH, RML is registered with: 169Yb; 65Zn; 124Sb.

and 2007); 134Cs; 131I; 57Co; 137Cs - Supplementary Comparisons

Radiations, TC-IR

(CRPs) and are approved by the CCRI(II); they refer to special types of samples and relative methods are accepted. IFIN-HH, RML is registered as *"CCRI(II)-S6.Radionuclide*", for the radionuclides 57Co and 131I, of interest in nuclear medicine.
