Electro-Tech systems 204 Operating Manual page 4

cost. The unit is a combination of an electrostatic fieldmeter, ±1200 Volt
charging source and a digital timer. The electrostatic detector is a non-
contacting, chopper type field sensor to ensure accurate and consistent
continuous measurements both in and outside ionized fields. The Model
204 displays both electrostatic voltage and decay time on a single 3½-
digit LCD meter with ½" character height. The meter is "zeroed" easily
with the turn of a small knob and does not need re-zeroing between
measurements.
The Model 204 has a detachable charged plate detector. When the
detector is installed the unit is a charged plate monitor with a range of
±2000V and a resolution of 1V.
With the detector removed the unit performs as an electrostatic fieldmeter
having a range of ±20kV at 1" (25.4mm) with a resolution of 10V.
Measurement accuracy is ±10% in this mode. It includes a convenient ¼"
(6.4mm) ground snap, compatible with most standard wrist strap cords, to
facilitate grounding and to increase accuracy.
The charging function automatically activates the timing mode. As the
applied 1200 Volt charge on the detector plate decays, either by
ionization or by dissipation through a resistance. The timer starts when
the measured voltage drops to 1000 Volts and stops when it decays to
100 Volts. Decay times to 60 sec. in 0.3 sec. increments, or as an option,
to 6 sec. in 0.3 sec. increments can be measured.
The 3½-digit LCD meter displays the voltage, polarity, or dissipation time
when the decay function of the Analyzer is used.
The Model 204 operates from a single 9V alkaline battery with a typical
operating life of approximately 20 hours. Low battery is indicated by all
decimal points illuminated on the DPM.
Figure 2-1: Model 204 Charged Plate Analyzer
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