DESCO WEST
- 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST
- One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website:
Desco.com
TB-3062
Page 6 of 8
© 2013 DESCO INDUSTRIES, INC.
Employee Owned
Desco
50005
Concentric Ring Probe
Cleaning the Digital Surface Resistance Meter
The area surrounding the cable jacks at the top end of the
meter should be wiped with a clean, isopropanol-alcohol
moistened cloth to remove skin oils that will accumulate
and affect the meter’s accuracy at high resistances. The
frequency of cleaning will depend on usage. Desco
recommends cleaning this area once a month. Cable jackets
should also be cleaned in this fashion.
Cleaning the Five Pound Electrodes
Per ANSI/ESD S4.1 “Clean the electrodes with a minimum
70% isopropanol-water solution. Make sure the 5 pound
electrodes’ conductive pads are dry prior to use.”
See specific product test standards for test lab specimen
cleaning instructions. Per ANSI/ESD S4.1 Worksurfaces
“The test specimens and electrodes shall be cleaned twice
with a minimum 70% isopropanol-water solution using a
clean, low-linting cloth each time.” (Note: The item should
then be conditioned for 72 hours minimum)
Calibration
The Digital Surface Resistance Meter is calibrated to NIST
traceable standards. Most users require calibration annually
which is our recomendation. Please e-mail
for details. In-house calibration can be
performed by using 1% resistors in each of the meter ranges.
Simply attach the resistors to the test leads using clips and
record the meter’s display. Keep the test leads uncrossed
and separated from one another. Should adjustment be
necessary, Desco recommends to return the unit to the
factory. Special equipment is required to adjust the meter.
Required Equipment
• Digital Multimeter: accurate to 1.25% @ 10VDC and
100VDC
• Fixed Decade Box with values from 10
3
- 10
12
:
accurate to ±2%, except at 10
11
and 10
12
(±5%)
• Thermometer: accurate to ±1°F
• Relative Humidity Meter: accurate to 2%
• Test Leads
• 99% Isopropyl Alcohol and Cleaning Wipes
Setup
• Test Area
- needs to be free of any high voltage
transformers or power supplies and away from any type
of fluorescent lighting or high power lighting.
• Worksurface
- needs to be covered with a grounded
conductive mat at 1.0 x 10
3
or less.
• Technician
- needs to be connected to equipment
ground with a 0 ohm resistor in the ground cord.
• Decade Box
- needs to be connected to equipment
ground.
Figure 7. Desco
50005
Concentric Ring Probe
The Desco
50005
Concentric Ring Probe is an instrument to
be used in conjunction with a resistance meter, such as the
Desco
19787
Digital Surface Resistance Meter, to measure
surface resistance per ANSI/ESD STM11.11 the test method
listed in Packaging standard ANSI/ESD S541 for surface
resistance of planar materials.
The Concentric Ring Probe (Ref: ANSI/ESD STM11.12) can
measure the volume resistance of planar materials using a
flat conductive metal plate (not included).
The Concentric Ring Probe may be used for the resistance
measurements of ESD packaging including static shielding
and other bags.
See
TB-3063
for more information.
Maintenance
The Digital Surface Resistance Meter requires little
maintenance. There are no user serviceable parts. If your
meter requires service beyond cleaning the electrodes or
replacing the batteries, please contact the factory.
This product utilizes a high frequency switching circuit to step
up the 3 volts from the batteries to the 100 volt test level.
Some users are able to discern a slight hum or buzzing when
the meter is powered. This is perfectly normal and is not
considered a flaw or defect.
Battery Replacement
The Function LEDs located above the push buttons will flash
when the battery voltage drops to approximately 2 volts.
This indicates that the meter’s batteries should be replaced.
Open the compartment located on the back of the meter
to replace the batteries. The meter uses two AA alkaline
batteries. Ensure that the batteries’ polarities are oriented in
the correct fashion to avoid any possible circuit damage.
