Monroe Electronics Electrostatic Fieldmeter - Static Monitor - model 177A - Manual (Page 16)

15
"E-rings" installed on them under the cover plate to make the screws captive and prevent their falling
into machinery below.
The probe assembly will need to be removed from the cover plate, for standardizing, calibration, or to
replace the gradient cap. This is done by removing the four cross point screws which secure the
phenolic mounting block to the hex standoffs, leaving the standoffs attached to the cover plate.
To reassemble the probe unit, reverse the above procedure. After the phenolic mounting block has
been re-secured to the four hex standoffs, the probe unit should be inspected to assure that an even
air gap exists completely around the gradient cap between the cap and the cover plate. If not, loosen
the two cross point screws which secure the probe body to the phenolic mounting block, and adjust
the probe body so that it is centered and completely surrounded by an even air gap.
Partially mate the card-edge fingers into the terminal block connector in the housing and tighten the
four outer screws in the cover plate 1-1½ turns at a time until the assembly is secured in the housing.
Standardization:
A simple accurate means of standardizing Model 1036 probes using any channel of the Model 177A
Static Monitor as a test vehicle is given here.
The primary reason for standardization of type 1036 probes is to assure interchangeability of probes.
The procedure is not suggested as routine, but is presented here in the event it becomes necessary
to re-standardize following replacement of a gradient cap or major probe overhaul. It should be
performed only under controlled conditions in a suitably equipped electronics laboratory. Monroe
Electronics recommends that all probe standardization be performed at its facility.
All type 1036 probes are shipped from the factory standardized in a uniform (parallel) electric field
using a fixture similar to that shown in Figure 12. The fixture consists of two flat rigid metal plates,
which are parallel and separated with insulators by a distance "d" of one inch and have side
dimensions of at least 5d (the bigger, the better; within practical limitations). The ground plate has a
hole in its center just large enough to provide clearance around the probe so that the probe does not
make contact with the plate. A calibrating voltage is applied to the gradient plate to establish a
reference field in the volume between the plates. This fixture is available from Monroe Electronics,
Inc. as part number 96102A.
Figure 12: Standardization Fixture (P.N. 96102) Setup for 1036 Probes
A Probe Standardization/Test Cable, Model number 1036/22C shown in Figure 13 below is required
to standardize or bench-test type 1036E-X probes. No special cable is required for type 1036F-X
probes.
1 0 3 6 P ro b e
A s s e m b ly