Operator's guide
Signal meter
The upper section of the HCU contains a simple voltmeter for
monitoring various signals from the instrument.
•
To monitor the velocity output, switch the dial to
V
VEL
.
•
To monitor the mass position output, switch the dial to
V
MASS
POS
.
•
You can set the range of the meter with the
RANGE
switch. When
switched to 10 V, the meter ranges from –10 to +10 V (as marked.)
When switched to 1 V, the range is –1 to +1 V.
Calibration and control
You can calibrate a 3V sensor through the HCU by connecting a signal
generator across the yellow and green
CALIBRATION SIGNAL
inputs
and turning the
CAL ENABLE
dial to
V
. The sensor's response can now
be monitored or recorded, and calibration calculations carried out.
The section of the HCU below the calibration lines controls the
instrument's mass control system. To initiate locking, unlocking, or
centring, hold down the
ENABLE
switch on the HCU
together with
the
appropriate switch for the command you want to issue for at least six
seconds.
Banana plugs
The remainder of the HCU provides useful connections for each of the
signal lines from the instrument, for aiaching to your own equipment
as necessary.
The inclinometer monitor unit
The borehole sensor system can operate successfully in boreholes with a
tilt angle up to 3.5 °. To check that the instrument is installed suitably
close to the vertical, a two-axis inclinometer is installed within the
sensor housing. The inclinometer monitor unit is used as a visual guide
to the sensor's tilt only, and should not be used if precise aiitude
information is required. You should check the inclination of the
instrument
before
unlocking the sensor masses, since too great a tilt can
damage the components.
December 2004
17
