Fluke Biomedical 1060AM - Manual (Page 16)

Victoreen 1060AM
Operators Manual
2-4
2.4.1 Input Channel Selection
The Select Input Channel command (SIC) allows one of the four input processing circuits to be activated
as the input to the pulse processing circuitry. The following codes are used to select the active channel.
Input Channel Hex Entry TLA
GM input C 68
PMT with preamp input
Positive
pulse A 42
Negative pulse A 43
Proportional D 50
Neutron input D 70
PMT w/o preamp B 44
2.4.2 High Voltage Adjustment
The Set High Voltage (SHV) command allows the user to adjust the high voltage for the appropriate
detector. Photo multiplier tube/scintillation detectors generally require that the overall gain be set by the
high voltage. The high voltage setting affects the input pulse amplitude and for this reason controls the
calibration of the detector. A detector/1060 provided as a system is factory calibrated. Typical 943 family
of detectors are set to obtain approximately 1 V pulse amplitude/0.5 MeV. When adjusting the high
voltage, caution must be exercised so as not to exceed the rating of the detector.
2.4.3 Low Discriminator Adjustment
The Set Low Discriminator (SLD) command controls the voltage threshold above which input pulses will
be processed. Input pulses with an amplitude less than the low discriminator setting will not be counted.
The typical setting is approximately 0.200V or 100 KeV.
2.4.4 High Discriminator Adjustment
The Set High Discriminator (SHD) command controls the voltage threshold below which input pulses will
be processed. Input pulses with amplitude that exceeds the high discriminator setting will not be counted.
The typical setting is approximately 7.00 V or 3.5 Mev.
2.4.5 Using other detectors
Typically, the high voltage setting and the low discriminator setting are used to calibrate the system.
These values may be found on the Calibration Data Sheet, or through the manufacturer of the detector.
Follow the manufacturers recommended calibration procedure when calibrating the system. Caution must
be exercised when setting the high voltage so as not to
exceed the detector rating.
2.4.6 Typical Multi-Drop Interface
(Block
Diagram)
Figure 2-3 illustrates the typical multi-drop interface block
diagram.
Figure 2-3. Block Diagram