Ultra Stable Surface DC Voltmeter Instructions
This meter uses a recessed rotating sensor (at the end of the metal cylindrical probe) to measure the voltage on conductive surfaces. (On insulating surfaces, the voltage is not as clearly defined, but this meter reads a number proportional to the electric field on insulating surfaces.) The reading is not affected by ions in the air.
To use, first plug in the probe and the 20 foot ground cable (supplied) into the side of the meter, and connect the alligator clip side of the ground cable to ground (such as metal plumbing, or the slightly-unscrewed screw from a wall outlet or switch plate). This defines the "zero" voltage. To adjust the OFFSET of the meter, turn the knob to 1999.9, with the black plastic (conductive) cap securely in place over the end of the probe. Then adjust the OFFSET so the display reads zero (+/- .1).
The meter is now ready to use. Turn the knob either to 19999 or 1999.9, which are the two ranges, in volts (at 1"). Remove the cap and hold the end of the probe a certain distance away from a surface to measure the voltage or electric field of that surface. At 1", the display shows voltage (+/-2%) of a conductive surface. At 2" it is half as sensitive (that is, a reading of 1500.0 means 3000 volts). These are correct numbers if the conductor is wide; that is, if it covers most of the "horizon" as seen by the probe. The above numbers are also correct if the surface is an insulator that is coated onto a (large) metal surface (that is, the insulator has a "ground plane".
However, if the surface is a bare insulator (without a ground plane or metal backing) that is charged, then the insulator will emit an electric field (but will not have a well-defined voltage). The electric field will be approximately the same at all distances from the charged sheet, and will not be 1/2 at 2", etc. The electric field in volts per meter is approximately 30 times the reading on the display. For example if the display reads 1000.0, the electric field is 30 KV/m. This is correct again if the sheet covers a majority of the "horizon" and if the sheet has a uniform amount of charge per area. If less than the full "horizon" is covered, the display will read a lower number. (This also works when measuring the atmospheric electric field; point the sensor upward. Remember that nearby conductive objects that are above the horizon will reduce the electric field).
If LOW BATTERY is displayed, push inward and slide off the back door to replace the 9-volt battery.
