Ludlum Measurements 3100, Руководство пользователя

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A-5
1. Three point tritium calibration is recommended by ANSI 42.30 (2002), and for the Model 3100,
requires three tritium gas concentration levels of approximately 25 µCi/m
3
, 500 µCi/m
3
, and 7500
µCi/m
3
. Using this method, the calibration constant is adjusted to correct the displayed tritium
concentration value of the Model 3100 at each of the three ranges. See Section A.2 Use of the CL-
1 Tritium Gas Calibrator.
2. Single point calibration is easier, requiring a single tritium gas concentration value. A
calibration constant is adjusted at this one concentration point to correct the displayed tritium
concentration value of the Model 3100. Using this method, all three ranges are set to the same
calibration constant. See Section A.2 Use of the CL-1 Tritium Gas Calibrator.
3. Three point gamma calibration uses an open-air
137
Cs calibration range. This calibration method
uses a manufacturer-determined gamma equivalence value to determine gamma fields to establish
known readings in the middle of each range. Using this method, a calibration constant is adjusted
to correct the displayed tritium concentration value of the Model 3100 at each of the three ranges.
In this mode, the gamma compensation chamber is disabled by substituting the calibration kit’s
gamma +HV replacement “slug” in place of the gamma +HV battery. See Section A.3 Use of a
Cs-137 Gamma Calibration Range.
4. Single point gamma calibration uses an open-air
137
Cs calibration range. This calibration uses a
manufacturer-determined gamma equivalence value to determine a gamma field to establish a
known reading. A calibration constant is adjusted at this one concentration point to correct the
displayed tritium concentration value of the Model 3100. In this mode, the gamma compensation
chamber is disabled by substituting the calibration kit’s gamma +HV replacement “slug” in place
of the gamma +HV battery. Using this method, all three ranges are set to the same calibration
constant. See Section A.3 Use of a Cs-137 Gamma Calibration Range.
A.2 USE OF THE CL-1 TRITIUM GAS CALIBRATOR.
A.2.1 Equipment Required.
a. Becton Dickinson Cl-1 Tritium Calibrator or equivalent traceable tritium gas injection device.
A.2.2 Unpacking.
a. The calibrator is shipped disassembled (in accordance with government regulations) into three main
parts.
1. Gas cylinder containing approximately 60 liters of tritiated methane at approximately 1600 PSIG.
2. Lecture bottle regulator and adaptor fittings.
3. Calibrator base plate.
b. Unpack each part and inspect them for damage.
A.2.3 Assemble Calibrator.
a. Remove the cap plugs from the regulator connector and outlet valve connector of the regulator. Inspect
and clean the regulator connector, if necessary, to ensure that the sealing O-ring is in place. Inspect and
clean the outlet valve connector also, if necessary.
b. Remove the threaded dust plug from the gas cylinder and inspect and clean the sealing surface, if
necessary.
c.
Adjust pressure by slowly turning the outlet pressure adjust knob clockwise to approximately 15 PSIG
on the outlet pressure gauge.