Guralp Systems CMG-40T - Manual (Page 10)

CMG-40T
a DM24, you can do this by sending a CENTRE command. If you are
using a Handheld Control Unit, you should select 1 SEC VEL from the
Velocity Select switch.
2. Measure the vertical mass position output with a 10 V voltmeter (see
Appendix A, “Connector pinouts” ) or by selecting MASS POS, V from a
Handheld Control Unit's Display Select knob. If using a HCU, also
check that the Centring Select knob is set to OFF.
3. If the vertical component needs adjusting, remove the cap on the lid
which protects the Verticalpot with a flat-bladed screwdriver (provided).
4. Insert the screwdriver through the opening, and engage the pot. An LED
flashlight 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.
10 Issue A