Ludlum Measurements 4404-16-4, Руководство пользователя

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Model 4404-16 Geo-Exploration System Technical Manual
Section 7
Ludlum Measurements, Inc. Page 49 April 2018
Hardware Calibration
A Ludlum Model 500 Pulser or equivalent is required. If the pulser does not
have a high-voltage readout, use a high impedance voltmeter with at least
1000 megohm input resistance to measure the detector voltage.
1. Remove the cover of the Model 4404-16.
2. Connect the Model 500 Pulser to the Model 4404-16 Channel #1
using an appropriate cable.
3. Adjust the pulser for 40,000 cpm and set the pulse amplitude to
-10 mV (negative amplitude).
4.
Start the Counter.exe program and “connect” to the Model 4404-
16.
5. Observe the Model 500 HV readout (or connect the high
impedance meter). Using your PC and the Model 4404-16
Counter software, set the HV control to 900 Vdc. Check for an
actual high voltage reading of 900 V ±4 volts and adjust if
necessary the potentiometer on top of the slave board (#1) and
closest to front panel for a reading of 900 Vdc on the voltmeter or
pulser. Connect the voltmeter between the HVR test point (+) on
the rear panel of Slave #1 and ground (the screw head (-) located
just to the right of the LMI logo on the panel). Adjust the HVR
pot located closest to the rear panel for a meter reading of 0.900
Vdc ±0.004 Vdc.
6. Set the HV to 500 and finally to 1200 Vdc and confirm that the
reading of the HV meter corresponds to the external voltmeter
within

5% of each reading.
7. Set the LLD for all channels to 100 and set the ULD to 200.
Note: this results in a calibration level of 10 mV threshold and 10
mV window.
Section
7