FlowStar2 LB 514
6. Validation using 3H- und 14C-Test sources
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6. Validation using 3H- und 14C-Test sources
The
3
H and
14
C-Test sources are specially developed to check and validate
the function of the FlowStar². The ID chip inside the test cell stores all rel-
evant information which will be transmitted to the FlowStar² when needed.
These test cells contain a sealed radioactive source. The source is sealed
in a plastic container and leakage tested. The radioactivity of the test cell
is far below the permitted limit. It might be required to register this cell if
you have a handling permit for radioactive sources. The nominal activity of
the
14
C test cell is around 200Bq. The nominal activity of the
3
H test cell is
about 6kBq. Precise activities can be found in the corresponding cell cer-
tificate.
Structure
A thick-walled plastic cuvette in a metal cell inset is filled with scintillator
and sealed on both sides. The radioactivity (
3
H or
14
C) was adsorbed on
the surface of the solid scintillator in a stable form. The cuvette was seal-
tested in accordance with 150/DIN 9978 (draft) (DIN 25426, see certifi-
cate).
Storage
The test source should be stored well protected in a dark room.
Procedure
An initial validation is necessary when the test source is used for the first
time. This initial validation measures the variation between the nominal
value of the test source and the measured value of the detector and spec-
ifies an initial nominal value. This variation is due to instrument / detector
variations mainly caused by the used photo multiplier tubes (PMT).
If another test source was used before the validation history must be reset
since a validation is always bound to a specific test source serial number.
This can only be done through the Berthold service.
In case of further validation measurements the results are compared with
the initial nominal value. If the variation is within the defined tolerance level
the validation is passed This procedure ensures a constant operation and
detects possible instrument problems. The Validation can be performed
with the 3H or 14C test sources (own, home made gamma source optional)
as well as the background cell. Since the background is depending on the
local conditions (cosmic radiation etc.) variations in the background could
occour.
