First encounters
4. Insert the screwdriver through the opening, and engage the pot. An LED
flash-light may be useful for locating the head.
5. Turn the pot either way until the offset readout is as close to 0 V as possible.
6. Repeat steps 2 – 5 for the North/South and East/West components.
3.4.2
Adjusting the mass position offsets with an HCU
Some 40T units are equipped with a remote mass centring option, which allows you
to adjust the internal potentiometers by applying voltages across control lines to the
sensor:
1. Bring the instrument into 1 second response mode by selecting
1 SEC VEL
from the
Velocity Select
switch.
2. Measure the vertical mass position output by selecting
MASS POS, V
from the
Hand-held Control Unit's
Display Select
knob.
3. Set the
Centring Select
knob to
V
.
4. Press the spring-loaded switch t or – to bring the mass position
offset from negative or positive values towards zero.
5. Repeat steps 3 and 4 for the
N/S
and
E/W
components.
12
Issue F - June 2019
