8 Maintenance
Maintenance
8.1 VM-810/VM-850 Receiver Calibration
The centerline, signal strength, and depth of your VM-810/VM-850 Receiver have
been calibrated to factory specified tolerances. It is to your advantage to monitor the
performance of your VM-810/VM-850 Receiver on a weekly basis.
Vivax-Metrotech recommends using a known conductor of which you know both
the location and the depth to test your VM-810/VM-850 Receiver, for example, a
buried service lone at your work location. If the Receiver gives significantly different
centerline, signal strength, or depth information from what you know to be true, it
should be re-calibrated by Vivax-Metrotech or a Vivax-Metrotech authorized Service
Center.
8.2 Replacing the VM-810/VM-850 Receiver Batteries
1. Have ready two D cell, 1.5V NEDA 13A, IEC LR20 (Int’l Std), or JIS AM1 (Jpn
Std.) type alkaline batteries.
2. Unscrew the retaining screw on the rear of the receiver.
3. Pull away the battery compartment from the receiver.
4. Unclip the two retaining lugs at the top of the battery holder allowing the lid to
hinge back.
5. Remove the two spent batteries and replace with fresh ones noting the polarity as
indicated on the battery holder. Close the lid ensuring the lugs have clipped into
place. Return the holder to the receiver and hand tighten the retaining screw.
8.3 Replacing the VM-810 Transmitter Batteries
Check the VM-810/VM-850 Transmitter batteries by pressing the POWER ON button.
The battery indicator lights will indicate if the batteries are good. If you need to replace
the batteries, follow the steps below:
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