Solutions of individual nuclides
Activity standards in the form of solutions are delivered in sealed Jena glass ampoules. They are 15.2 mm in diameter, about 60 mm in height, and their wall thickness is 0.5 mm. They normally contain 2 mL of the respective solution.
The chemical composition of the solution is selected such that its stability is guaranteed at a minimum concentration of solid matter and acid. When dilutions are prepared, in particular in glass jars, the concentration of the inactive carrier stated in the calibration certificate should at least be maintained to avoid wall adsorption of the radionuclide.
On request, solutions of lower specific activity can be prepared by dilution of the solutions available. The customer will be charged with the production costs of the solution.
At irregular intervals, activity standards of other nuclides than those stated in the Table "Activity standards in the form of solutions" can be delivered in the form of solutions (cf. above: Activity standards).
The calibration certificate is accompanied by a data sheet stating the values of the radionuclide constants (photon energies and photon emission probabilities per decay and, where appropriate, maximum and mean beta-particle energies) recommended by the PTB.
Figure 1: Ampoule dimensions (in millimetres)
Table 2: Activity standards in the form of solutions
| Nuclide |
Half-
life |
Chemical compo-
sition of the
solution |
Specific
Activity
in kBq/g |
Uncer-
tainty
in % (3) |
Availa-
bility |
| H-3 |
12.33 a |
H2O |
5
50;500
5000;50000 |
1.7
1.4
1.4
|
ex stock |
| Be-7 |
53.23 d |
BeCl2
HCL 0.1 mol/L |
200;2000 |
1.4
|
(2) |
| C-14 |
5730 a |
Na2CO3
NAOH 0.001 mol/L
|
10;100
1000;10000 |
3.3
3.3
|
ex stock |
| Na-22 |
950.5 d |
NaCl
HCL 0.1 mol/L |
10
100;1000 |
1
0.7
|
ex stock |
| Cr-51 |
27.71 d |
CrCl3
HCL 0.1 mol/L |
20
200;2000 |
1.4
1 |
(1) |
| Mn-54 |
312.15 d |
MnCl2
HCL 0.1 mol/L |
10
100;1000 |
1
0.7
|
ex stock |
| Fe-55 |
1005 d |
FeCl3
HCL 0.1 mol/L |
200;2000 |
2.5 |
ex stock |
| Co-57 |
271.83 d |
CoCl2
HCL 0.1 mol/L |
20
200:2000 |
1.4
1
|
ex stock |
| Co-60 |
1925.3 d |
CoCl2
HCL 0.1 mol/L |
4:40
400:4000 |
1
0.7
|
ex stock |
| Zn-65 |
243.94 d |
ZnCl2
HCL 0.1 mol/L |
20
200;2000 |
1.4
1.4
|
ex stock |
| Sr-85 |
64.85 d |
SrCl2
HCL 0.1 mol/L |
20
200;2000 |
1.4
1
|
(2) |
| Y-88 |
106.63 d |
YCl3
HCL 0.1 mol/L |
10
100;1000 |
1.4
1
|
(2) |
| Sr-89 |
50.53 d |
SrCl2
HCL 0.1 mol/L |
2;20
200;2000 |
2
1.7
|
(1) |
| Sr-90 |
28.81 a |
SrCl2 + YCl3
HCL 0.1 mol/L |
0,4;4
40;400;4000 |
1.7
1.5
|
ex stock |
| Cd-109 |
462.1 d |
CdCl2
HCL 0.1 mol/L |
10;100
1000 |
1.7
1.7
|
ex stock |
| Sb-125 |
1007.7 d |
SbCl3 und Weinsäure
HCL 2 mol/L |
10
100;1000 |
1.7
1.4
|
ex stock |
| I-125 |
59.39 d |
NaI und Na2S2O3 mit
0.1 % Formalin |
10
100;1000 |
1.7
1.4
|
(1) |
| I-129 |
1.57*107 a |
NaI und Na2S2O3 mit
0.1 % Formalin |
1 |
3.3
|
ex stock |
| I-131 |
8.021 d |
NaI und Na2S2O3 mit
0.1 % Formalin |
4
1000 |
1
1.7
|
March/
April |
| Ba-133 |
10.54 a |
BaCl2
HCL 0.1 mol/L |
0,4;4
40;400;1000 |
1.4
1
|
ex stock |
| Cs-134 |
754.0 d |
CsCl
HCL 0.1 mol/L |
10
100;1000 |
1
0.7
|
ex stock |
| Cs-137 |
30.13 a |
CsCl
HCL 0,1 mol/L |
0,4;4
40;400;4000 |
1.4
1
|
ex stock |
| Ce-139 |
137.66 d |
CeCl3
HCL 1 mol/L |
10;100
1000 |
1
1
|
(2) |
| Ce-144 |
284.7 d |
CeCl3
HCL 1 mol/L |
10;100
1000 |
1.4
1.4
|
ex stock |
| Pm-147 |
958.20 d |
NdCl3
HCL 0,5 mol/L |
40;400
4000 |
2
2
|
ex stock |
| Eu-152 |
13.53 a |
EuCl3
HCL 0,1 mol/L |
4
40;400;4000 |
2
1.4
|
ex stock |
| Tl-204 |
1381 a |
Tl2SO4
HNO3 0,1 mol/L |
6
60;600 |
1.7
1.4
|
ex stock |
| Bi-207 |
31.55 a |
BiCl3
HCL 1 mol/L |
15 |
1.5
|
ex stock |
| Pb-210 |
22.3 a |
Pb(NO3)2 + Bi(NO3)3
HNO3 1,2 mol/L |
1,5
15;150;1500 |
2
1.5
|
ex stock |
| Ra-226 |
1600 a |
BaCl2
HCL |
0,1;1 |
1.4
|
ex stock |
| Am-241 |
432,2 a |
La(NO3)3
HNO3 0,1 mol/L |
1;4
10;400;4000 |
1.4
1
|
ex stock |
| (1) |
The solutions are prepared and delivered yearly. The dates of delivery will be announced in good time. Please let us know about which deliveries you wish to be informed. |
|
|
| (2) |
Raw solutions of this radionuclide are offered only rarely by the producers. The dates of delivery for activity standards are, therefore, undefined. |
|
|
| (3) |
The uncertainty stated is the relative expanded uncertainty of measurement in percent obtained by multiplying the standard uncertainty by a coverage factor k = 2. |
Mixed solutions
These solutions are intended to serve as calibration solutions for systems used to measure aqueous samples of low activity at short distances from the detector.
Available are plastic bottles (content: 100 mL) or glass ampoules (content: 2 mL) of identical total activity. The carrier concentration of the solution in plastic bottles is so high that a filling quantity of up to 1 L can be obtained when water which has been distilled twice is added after the solution has been filled into the measuring vessel. The ampoules are delivered together with a carrier solution. A data sheet states recommended values of half-lives, photon energies and photon emission probabilities per decay.
Mixed solution 2 (ML 2) is intended to serve as a reference solution for waste water measurements in nuclear power plants.
Mixed solution 4 (ML 4) allows germanium detectors to be quickly and accurately calibrated in the low-energy range between 40 keV and 130 keV. As no experience has so far been gained as regards the stability of this solution during further processing, the PTB's advice is not to mix this solution with other solutions.
Mixed solution 5 (ML 5) serves to quickly and accurately calibrate radiation detectors - in particular NaI(Tl) detectors - with respect to the efficiencies specific to the cesium isotopes contained in it. The activity values A are set in such a way that, related to January 1,1996, the following is valid:
A(Cs-137)/A(Cs-134) = 6.8.
The relative expanded measurement uncertainty (k = 2) of the individual activity values lie between 1.0 % and 1.7 % for all solutions.
Mixed solutions of other radionuclide compositions are available from commercial suppliers who have a calibration laboratory which has been accredited within the German Calibration Service (DKD). DKD-calibration certificates issued by accredited laboratories document that the object calibrated is traceable to national standards of the PTB. Please phone PTB in case of need.
Table 3: Composition of the mixed solutions
Mixed solution 2
|
|
Gamma radiation |
|
| Nuclide |
Half
life |
Energy
in keV |
Emmission-
probability
in % |
Activity
in kBq |
| Co-60 |
1925.3 d |
1173.2
1332.5
|
99.587
99.983
|
10 |
| Cs-134 |
754.0 d |
569.3
604.7
795.9
|
15.39
97.63
85.4
|
10 |
| Cs-137 |
30.13 a |
661.7
|
85.1
|
10 |
|
|
Gamma radiation |
|
| Nuclide |
Half-
life |
Energy
in keV |
Emmission-
probability
in % |
Activity
in kBq |
| Co-57 |
271.83 d |
122.1
136.5
|
85.60
10.68
|
4 |
| Cd-109 |
462.1 d |
88.0 |
3.63 |
20 |
| Pb-210 |
22.3 a |
46.54 |
4.24 |
20 |
| Am-241 |
432.2 a |
59.54 |
36.0 |
4 |
Mixed solution 5
Cs-134/Cs-137-mixed solution
|
|
Gamma radiation |
|
| Nuclide |
Half-
life |
Energy
in keV |
Emmission-
probability
in % |
Activity
in kBq at
1.1.1996 |
| Cs-134 |
754.0 d |
569.3
604.7
795.9
|
15.39
97.63
85.4
|
3 |
| Cs-137 |
30.13 a |
661.7
|
85.1
|
19 |
The statements for the emission probabilities per decay in table 3 are partly incomplete. Additionel photon radiations with low emission probabilities are listed in the report PTB-Ra-16.
