At 4", multiply reading by 2 - 40kV
range
At 6.5", multiply reading by 3 -
60kV range
At 8.5", multiply reading by 4 -
80kV range
The LED rangefinder system is
calibrated at the 1" distance only.
2. Repeat the above for additional
measurements.
3. To turn the instrument off, press and
hold the HOLD/OFF button for at
least 3 seconds until display readings
disappear.
AUTO SHUTDOWN TIMER
During normal operation (not during
ZERO) a blinking decimal point
indicates the AUTO SHUTDOWN
TIMER is enabled. If the AUTO
SHUTDOWN TIMER is disabled the
decimal point will be on continuously.
Holding down the ZERO button, while
unit is ON, for less than 3 seconds
resets the AUTO SHUTDOWN TIMER
(if enabled). The AUTO SHUTDOWN
TIMER is enabled or disabled by
turning on the unit and keeping the
ON/ZERO button pressed then toggling
the HOLD/OFF button. Enable/disable
of the AUTO SHUTDOWN TIMER is
indicated by the decimal point:
DP on = timer on, DP off = timer off.
AUTO SHUTDOWN TIMER state is
maintained during power off. AUTO
SHUTDOWN TIMER can be
continually toggled as long as the
ON/ZERO button remains pressed, up
to 20 seconds, after which the unit will
turn off. A blinking decimal point
indicates the AUTO SHUTDOWN
TIMER is active. During the last minute
before power off ALL annunicators will
blink at a fast rate. Pressing any button
will reset the timer. Timeout is
nominally 15 minutes.
Operating Notes:
• The case of the instrument is made of
a material which is sufficiently
conductive to provide a grounding
path via the person holding the
instrument or a grounded wrist strap
in contact with the case.
• The output jack accepts a standard
3/32" (2.5mm) monaural phone plug
and is provided in order that the
output of the instrument may be
connected to an oscilloscope, strip
chart recorder, external meter or
other device. The output voltage at
this jack is ±2 volts for full input
(20kV/in. at 1") for high impedance
loads (100 k
S
or greater). It has an
impedance of approximately 100
S
.
The shell of this jack may be used to
provide a "hard ground" connection.
• If you press the on/zero button
during operation, the Field Meter
begins the auto zero function and
displays the value. It you do not
complete the auto zero operation, the
meter is not correctly zeroed.
• For extended monitoring of
materials, a +9 volt power supply
(such as Radio Shack #273-1552)
may be substituted for the battery.
Measurement Accuracy
The accuracy of measurement is
dependent on a stable ground reference
and the 1 inch measuring distance as
previously noted. It is also dependent on
the “aspect ratio,” relating the size of
the object to be measured to the
PS-2061
Page 2 of 4
Figure 3. Taking readings in the
“HOLD” mode
measurement distance. This ratio should
be at least 3 for best accuracy, i.e. the
object should be at least a 3 inch square
when measuring at a 1 inch distance.
Accurate measurements may be made at
other measurement distances by scaling
the meter range and observing the
proper aspect ratio. For example, at a
measurement distance of 3 inches, the
object being measured at this distance
should be at least a 9 inch square.
Auditing of Ionization
Equipment with the 42721
Due to its unique measuring circuit the
digital field meter will accurately
operate in an ionized air stream or
ionized field.
We offer a "Portable Ionization Test
Kit" (Item 42755) designed to facilitate
routine auditing and periodic testing of
ionization equipment. The Test Kit is
designed to be used in conjunction with
the 42721 meter. The Field Meter and
test kit combination can be used to audit
an ionizer's overall performance. The
highly portable Test Kit allows the user
to make quick and accurate balance
level and neutralization efficiency
measurements. The Test Kit is sold
separately as item 42755. The Portable
Ionization Test Kit includes a slide-on
adapter plate, a +/- 1000V charging unit
and a durable molded carrying case
along with the Digital Fieldmeter.
In order to test ionization equipment to
an industry recognized standard, we
recommend the test procedure published
by the ESD Association as Standard 3.1.
This standard may be obtained from the
ESD Association, 7902 Turin Road,
Suite 4, Rome, NY 13440-2069, (315)
339-6937.
Thousands
Tens
Hundred
© 2005 DESCO INDUSTRIES INC.
Employee Owned
