BERTHOLD TECHNOLOGIES LB 480, Руководство пользователя, Страница: 344 / 450

54733-10BA2L
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02.2017
Menu Structure Volume 3
2 Product Density
This parameter is required for Calibration Method 1-POINT to
determine the full count rate automatically.
For liquids you have to enter the fluid density in kg/m
3
, for solids,
the bulk density.
If you known the fluid density and the bulk density only approxi-
mately, then you have to enter the lowest expected value.
3 Compensation Mode
The following settings are possible:
• OFF
The compensation is switched off.
• AUTO PRC (Product Radiation Compensation)
Only required for level measurements on products containing
natural radioactivity. This requires a compensation measure-
ment which consists of the same detectors and is mounted at
the same height on the container as the level measurement.
The compensation measurement should not receive any radia-
tion from the radiation source for the level measurement.
Therefore it is mounted on the container offset by 90 degrees.
For calibration, the compensation measurement must be
mounted and connected, and level measurement must be
logged in at the master. Additional parameters required for this
calibration appear on the Calibration menu.
The following requirements are necessary for a PRC-measure-
ment:
–
the detector for the compensation measurement must be
the same as for the level measurement
– the distance to the vessel wall must be equal for both
detectors
– the vertical mounting position of the two detectors must be
equal
– the vessel wall thickness of the two detectors must be equal
– the radioactivity present in the product must be evenly dis-
tributed
– the 0% and the 100% point must be calibrated. The back-
ground of both detectors must be less than the respective
100% value.
The PRC measurement cannot be used if the radiation source is
mounted in a dip tube in the container, because the radiation from
this source would also be measured by the PRC-detector.
Please note that complete data archiving is not possible with the
PRC function enabled.
Detector for
compensation
measurement
Detector for level
measurement