Monroe Electronics Electrostatic Voltmeter - Isoprobe® - model 244A - Manual (Page 10)

10
SECTION 3
CONTROLS AND INDICATORS
FRONT PANEL CONTROLS - FIG. 3-1
A. STANDBY/OPERATE SWITCH:
Controls the operating condition of the unit.
1. STANDBY - Starts the probe oscillating, but leaves the H.V. disabled, unless
activated by the remote (rear "slave") connector.
2. OPERATE - Turns on the H.V. supplies, only if the probe is plugged in and
the fork is oscillating. This position overrides the remote control.
B. ON INDICATOR:
Indicates that the low voltage supplies are on and operational status is
controllable by remote operation.
C. OPERATE INDICATOR:
Indicates that the H.V. is on and that the probe housing may be at any voltage
up to ±3400V. Excessive gain or excessive loading on the probe such as probe
contact to a grounded surface, causes the operate light to blink, indicating a
malfunction.
D. BALANCE:
Balances internal probe contact potential to obtain probe to surface spacing
insensitivity. This adjustment procedure is described in Section 4B (may also be
used for large zero offset when spacing insensitivity is not needed).
E. ZERO:
Compensates for unwanted offsets in the range of ±4 volts. This does not affect
probe-to-surface spacing sensitivity.
F. RESPONSE SPEED (GAIN):
Adjusts system speed-of-response, static accuracy and stability by varying open-
loop system gain. Excessive gain causes system instability and degradation in
static error. Insufficient gain produces static error and slow speed- of- response.
System gain and responses vary with probe-to- surface spacing and must be
compensated by adjustment of this control.
G. PROBE CONNECTOR:
Connector for attachment of 1017 probes. The connector is interlocked with the
operate switch and will shut down the high voltage section when probe is
disconnected.
NOTE: A special shortened pin is used in P201 (on probe) for safety purposes in
other instruments in the ISOPROBE Series.