CharlesWater Micro Meg Installation guide

Micro Meg™ Pocket Megohmmeter
Operation and Maintenance
Figure 1. 99035 MicroMeg Pocket
Megohmmeter
Description
The Charleswater 99035 Micro
Meg Pocket Megohmmeter is a
portable test instrument designed
for measuring both surface and
surface-to-ground resistance of static
dissipative and conductive materials.
Seven color-coded LEDs, read from
right to left, easily identify static
dissipative and conductive ranges.
The Micro Meg will test materials
with surface resistivity of 1x10E5
to 1x10E10. This test instrument is
ideally suited for Quality Control and
Field Service personnel as well as
for use in routine auditing of your
ESD protective materials. The Micro
Meg features simple one-button
operation and a 9V battery for ease
of use and maximum portability. This
auto-ranging instrument weighs only
six ounces. The high-impact plastic
case ensures durability despite the
meter’s light weight.
The Micro Meg has not been
designed to meet IEC 61340-4-1
test equipment requirements and
therefore measurements obtained
with this device may not agree with
measurements taken according to
the EN 61340-5-1 Test method A.1
test procedure. This test instrument is
intended for use only as an auxiliary
tool for monitoring surface resistance
performance.
If you are interested in obtaining a
meter which does meet all the test
equipment requirements of IEC
61340-4-1, we recommend our model
99105 Surface Resistance Test Kit.
For more information on this product
ask for Techical Bulletin PPE-5075.E.
Installation
Remove the meter from the carton
and inspect for damage. Each unit
should be fully charged and includes:
1 Micro Meg Pocket Megohmmeter
1 Surface-to-Ground, cord assembly
1 9V battery
Properly store the megohmmeter and
its component assemblies when not
in use.
Operation
The Micro Meg will perform Surface
Resistivity and Surface-to-Ground
resistance measurements. Work
surfaces and materials to be tested
should be cleaned prior to testing
to ensure that surface dirt and
contamination do not affect results.
It is recommended that non-silicone
and non-alcohol based cleaners
such as Charleswater’s Reztore™
Surface and Mat Cleaner be used for
regular cleaning of ESD protective
work surfaces. When non-ESD
surfaces are being used, Reztore™
Topical Antistat is recommended for
eliminating static charge generation.
Surface and Surface-to-Ground
resistance readings are indicated by
the series of LEDs on the face of the
meter. The LEDs are read from right
to left as follows:
1. RED – Meter on and battery
functioning
2. GREEN – 5 x 10E10
3. GREEN – 1 x 10E9
4. GREEN – 1 x 10E8
5. GREEN – 1 x 10E7
6. YELLOW – 1 x 10E6
7. YELLOW – 1 x 10E5
Each LED indicates one order of
magnitude of resistance. If the test
surface is conductive to less than
10E5, all the LEDs will be lit. If
it is neither conductive nor static
dissipative, only the red “On” LED will
be lit.
Surface Resistivity
Measurements
Surface resistivity measurements
are made using only the meter
without the cord assembly. When
the white button is depressed a test
voltage of 9 VDC is applied to the
meter’s center electrode. The second
resistivity electrode will supply the
resistance bridge and provide the
measurement. To perform surface
resistivity tests, follow these simple
instructions:
A. Check battery operation by
depressing the white button on the
center of the megohmmeter. The red
“On” lamp at the far right should light
to indicate that the unit is functioning
properly.
B. Place the meter on the surface
being tested. All three electrodes
should make contact with the surface.
C. Press the white button. The
surface resistance will be indicated
by the number of LEDs which light
up. The more lights illuminated,
the greater the conductivity of the
surface. The measurement is in
ohms/square.
Made in the
United States of America
TECHNICAL BULLETIN PPE-5046.E
Unit 17. Millbrook Business Park, Sybron Way • Crowborough, East Sussex TN6 3JZ United Kingdom
Phone: [phone], Fax: [phone] • Internet: Charleswater.co.uk
PPE-5046.E September 2011 Page 1 of 3 © 2011 CHARLESWATER LTD.
Figure 2. Cleaning the work surface
before testing.

Figure 3. Measuring surface
resistivity.
Surface -to-Ground
Measurements (RTG)
The Surface-to-Ground feature is
best used when expected results
are less than 10E6 ohms, and when
residual voltages can be removed
from the test surface. Residual
voltages may cause the two upper
range LEDs to light, resulting in a
false reading.
When the Surface-to-Ground cord is
plugged in, voltage is diverted from
the center electrode to the cord in
order to measure resistance. When
making Surface-to-Ground tests,
follow these procedures:
A. Check battery operation by
depressing the white button. The red
“On” lamp will indicate that the unit is
functioning properly.
B. Plug the Surface-to-Ground
cord into the left side of the
megohmmeter.
Figure 4. Installing Surface-to-Ground
cord assembly.
C. Place the Micro Meg on the test
surface.
D. Connect the test cord to the
ground-point for the surface.
E. Press the white button. The LEDs
will indicate the test results. The
measurement is in ohms.
Figure 5. Measuring
Surface-to-Ground resistance.
F. Unplug the cord when testing is
finished.
Battery Operation
Battery function is automatically
checked by the unit when the meter
is turned on. If the battery voltage
drops below 8 VDC, the red LED on
the far right of the meter will not light,
indicating a “low battery” condition.
Replace battery with a new 9V
alkaline battery.
Maintenance
Your Micro Meg will require very
little maintenance, and there are few
user-serviceable parts. If your meter
requires service beyond the simple
procedures described below please
contact the factory.
Electrode Cleaning
To assure accurate measurements
the electrodes should be kept as
clean as possible. A thorough
cleaning at least every 3 months is
recommended. The following is the
recommended cleaning procedure:
1. Carefully remove the electrodes
from their snap-jacks using a screw
driver or other blunt flat bladed
object. Avoid scratching or bending
electrodes.
2. Clean both the snap stud and the
electrodes with a cotton swab soaked
in isopropyl alcohol. Check the rubber
centers for wear - the rubber should
form a convex spot on the bottom of
the electrode. The three electrodes
will be checked with each annual,
factory calibration. If electrode
replacement is recommended,
the customer will be notified with
estimated charges before any
changes are made.
Theory of Operation
The Micro Meg measures resistance
by setting up a bridge between two
precision 1% resistors of known value
and the surface tested, of unknown
value. When the white button is
depressed a test voltage of 9 VDC is
applied to the megohmmeter’s center
electrode or ground cord, depending
on the test being performed. One of
the bottom electrodes on the outside
of the meter supplies the resistance
bridge. The test voltage resulting
from the bridge is compared to
reference voltages established by
six trimming potentiometers. Two
integrated circuits are configured
as comparators to check the
voltage from the bridge against
the potentiometers. Based on the
setting of each potentiometer, the
appropriate LED is lit.
Specifications
Sensitivity Range
Surface Resistivity
Less than 10E10 ohms/sq
Surface-to-Ground
Less than 10E9 ohms
LED Key (from right to left)
1. Red
>10E10, Meter On, and
Battery OK
2. Green
10E10 Static Dissipative
3. Green
10E9 Static Dissipative
4. Green
10E8 Static Dissipative
5. Green
10E7 Static Dissipative
6. Yellow
10E6 Static Dissipative
7. Yellow
10E5 Conductive
Snap Socket
Conductive Rubber
Snap Stud
Unit 17. Millbrook Business Park, Sybron Way • Crowborough, East Sussex TN6 3JZ United Kingdom
Phone: [phone], Fax: [phone] • Internet: Charleswater.co.uk
PPE-5046.E Page 2 of 3 © 2011 CHARLESWATER LTD.
Figure 6. Cleaning the electrodes.

Test Sample Size
7.62cm x 3.81cm or larger
General Characteristics
Power Supply
9 volt alkaline battery(included)
Test Voltage
Nominal 9 volts
Electrodes
Steel and conductive rubber
Temperature Range
Operating 10°C to 40°C
Storage -15°C to +60°C
Relative Humidity
0% to 99% (non-condensing)
Operation
Resistance bridge
Readout
Seven LEDs
Resolution
One order of magnitude
Accuracy
±10% all, except ±20% 10E9, 10E10
Repeatability
±3%
Weight
6 ounces
Dimensions
10.16cm x 6.35cm x 4.45cm
Calibration
The Micro Meg is calibrated to NIST
traceable standards. It may be
returned to the factory for calibration.
Contact our Customer Service
Department at 0044 (0) 1462 672005
for a Return Material Authorization.
Written Purchase Orders are required
for calibration services.
A check on the function of the Micro
Meg can be performed with the
following procedure. You will need
1% resistors of the following values:
5 x 10E5 ohms; 5 x 10E6 ohms; 5
x 10E7 ohms; 5 x 10E8 ohms, 5 x
10E9 ohms, and 1 x 10E10 ohms.
These precision resistors will be
placed across the two electrodes on
the bottom of the meter (see Figure
7).
A. Place the Micro Meg on an
insulator (e.g. Teflon or glass) and
press the white test button. Only the
first red LED on the right, marked
“On” should be illuminated. If this
LED fails to light, the battery should
be replaced before proceeding.
B. Place the 1 x 10E10 ohms resistor
across the middle electrode and the
side electrode as illustrated in Figure
7. Press the test button. The second
LED should light. Be sure not to
contact the leads or the buttons as
your body’s resistance will affect the
readings. Then use the 5 x 10E9,
the 3rd LED should light. Continue
down the line of resistors to test all
the ranges.
Figure 7. Calibration of the Micro
Meg
C. Continue this process with each
consecutive resistor, checking to
make sure the appropriate LEDs
are illuminated. If all resistors check
properly, the unit’s calibration is
verified.
Adjustment
Unauthorized servicing or
modifications to the Micro Meg will
void the product warranty. Servicing
should only be performed by the
factory. See warranty section for
repair charges.
Resistor
Electrode
Unit 17. Millbrook Business Park, Sybron Way • Crowborough, East Sussex TN6 3JZ United Kingdom
Phone: [phone], Fax: [phone] • Internet: Charleswater.co.uk
PPE-5046.E Page 3 of 3 © 2011 CHARLESWATER LTD.
Limited Warranty
Charleswater expressly warrants that
for a period of one (1) year from the
date of purchase, Charleswater
Micro
Megs
will be free of defects in material
(parts). Within the warranty period,
the material will be tested, repaired
or replaced at Charleswater’s option,
free of charge. Call Customer Service
at 00 44 (0) 1892-665313 for a Return
Material Authorisation (RMA) and for
proper shipping instructions and address.
You should include a copy of your
original packing slip, invoice, or other
proof of purchase date. Any unit under
warranty should be shipped prepaid
to the Charleswater factory. Warranty
replacements will take approximately two
weeks.
Warranty Exclusions
THE FOREGOING EXPRESS
WARRANTY IS MADE IN LIEU OF ALL
OTHER PRODUCT WARRANTIES,
EXPRESSED AND IMPLIED,
INCLUDING MERCHANTABILITY
AND FITNESS FOR A PARTICULAR
PURPOSE WHICH ARE
SPECIFICALLY DISCLAIMED. The
express warranty will not apply to
defects or damage due to accidents,
neglect, misuse, alterations, operator
error, or failure to properly maintain,
clean or repair products.
Limit of Liability
In no event will Charleswater or any
seller be responsible or liable for
any inury, loss or damage, direct or
consequential, arising out of the use
of or the inability to use the product.
Before using, users shall determine
the suitability of the product for their
intended use, and users assume all risk
and liability whatsoever in connection
therewith.
LED Value Resistance Value
10E10 Green < 5 x 10E10 ohms
10E9 Green < 1 x 10E10 ohms
10E8 Green < 1 x 10E9 ohms
10E7 Green < 1 x 10E8 ohms
10E6 Yellow < 1 x 10E7 ohms
10E5 Yellow < 1 x 10E6 ohms