If you wish to perform a microgravity survey within about a 2 mgal range, set the MVR system power supply voltage to 10 volts. You can clamp the dial in one place and simply record the Feedback Voltage output at each station. The calibration factor is then used to convert measured voltage differences to gravity differencess. One advantage of this form of surveying is that NOT turning the nulling dial eliminates any source of circular error when making a gravity measurement.

For standard point-to-point measurements of gravity differences, set the MVR system power supply voltage to 30 volts. Remember that when using MVR Feedback, the beam is ALWAYS being forced to the reading line, provided the nulling dial is set within the approximately 2 or 20 milligal range of the system. Turning the nulling dial causes the Feedback card to adjust the force required to KEEP the beam at the reading line.