TECHNICAL BULLETIN TB-3014

Surface Resistance Test Kit

Operation and Maintenance Made in America

• Footwear - ESD S9.1 - Footwear -

Resistive Characterization
• Garments - ESD STM2.1 Garments
• Seating - ESD STM12.1- Seating -
Resistive Measurement
• Floor/Footwear - ESD STM97.1 -
Floor Materials and Footwear-
Resistance Measurement in
Combination with a Person
• Workstations - ESD-ADV53.1 - ESD
Protective Workstations

Versatility:
Measures RTT, RTG or Resistivity
(requires optional Resistivity Attachment,
item 19782)
• Quick Checks - Surface resistance exponent
number illuminates immediately i.e. 8 = 108 ohms or
100,000,000 ohms
• Periodic Checks of Installed Products - Surface
resistance exponent number illuminates immediately and
displays Temperature and Relative Humidity during 15
second electrification period making numerous measure-
ments and calculations to then display mantissa i.e. if
LED displays 8 and LCD displaying 7.14 as mantissa =
7.14 x 108 ohms or 714,000,000 ohms
• Test Lab Evaluation of Product - Display same as
Periodic Check above

Figure 1. Item 19780 Surface Resistance Test Kit The Surface Resistance Test Kit is NIST calibrated and
items available are:
Description Model Description Power
The Surface Resistance Test Kit is a portable, accurate, and 19780 Surface Resistance Test Kit 2 x AA Batteries
versatile instrument designed to measure resistance
between two points (RTT), surface to ground (RTG), and 19781 Meter & Attachment 2 x AA Batteries
surface resistivity in accordance with ESD Association 19782 Resistivity Attachment N/A
Standard S4.1 including:
• Resistance measuring accuracy ± 10% A pair of 5-pound Electrodes (item 50003), and or a pair of
(E12 & greater ±20%) Test Leads (item 19783) can be bought separately.
• Resistance range <1.0 x 103 ohms to >1012 ohms
• Open circuit voltages of 10 and 100 volts ± 5% Inspection
• Electrification period of 15 seconds Remove the meter from the carton and inspect for damage.
• Electrodes (two) 5 pounds ± 2 oz with 50-70 durometer Each Surface Resistance Test Kit should include the
conductive pads following:
1 Protective carrying case
In addition, the Meter measures ambient temperature and
1 Meter
relative humidity.
2 Test leads
The Surface Resistance Test Kit (or its Meter) is referenced 2 5-pound electrodes
and designed to be used to make measurements in 2 AA alkaline batteries
accordance with the test methods in:
• Worksurfaces - ESD S4.1 Worksurfaces - Resistance Properly store the Meter and component assemblies when
Measurements not in use.
• Floors - ANSI/ESD S7.1- Resistive Characterization of
Materials Floor Materials

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST - 90 Hudson Road, Canton, MA 02021-1407 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.desco.com

© 2005 DESCO INDUSTRIES INC.

TB-3014 6/05 Page 1 of 5 Employee Owned
 ESD protective products should be tested:
A. Prior to installation to qualify for listing in user's ESD E
control plan approved ESD protective materials (see
ANSI/ESD S20.20 paragraph 6.1.1.2)
B. During initial installation
C. For periodic checks of installed products as part of ESD
control plan compliance verification plan B A
Per ANSI/ESD S20.20, test equipment is required to enact
Compliance Verification Plan Requirement - "Test C
equipment shall be selected to make measurements of
appropriate properties of the technical requirements that are
incorporated into the ESD program plan."

Electrification Period G D
The Surface Resistance Test Kit provides the proper
electrification period of 15 seconds per ESD S4.1, after
numerous readings and calculations are executed, then F
displays surface resistance mantissa measurement (Note:
most analog type meters display measurements
instantaneously). Figure 2. Features of the Surface Resistance Meter

When the Test Button is depressed, the liquid crystal display

(LCD) will indicate: Exponent Color
• Temperature in degrees Fahrenheit (tolerance ±5°F, <3, 3 Red
typical) 4, 5 Green
• Temperature in degrees Celsius (tolerance ±3°C, typical) 6, 7, 8 Blue
• Humidity as percentage (from 5% - 95% tolerance, ±10 9, 10, 11 Green
typical) 12, >12 Yellow
• Surface resistance mantissa (with exponent displayed via
LED, measurement in ohms) Five Function LED’s identify the measurement being
displayed (see B below).
Measurement being displayed is identified by the • When battery voltage drops to approximately 2 volts, one
illuminated function LED. The surface resistance exponent of the Function LED's to the right of the red pushbutton
(or power of number) is immediately illuminated and switch will begin to flash, indicating the need to replace
remains illuminated measuring the range the surface batteries.
resistance in ohms.
B. Liquid Crystal Display (LCD): Mantissa is displayed via
Reference Literature 9/16" high liquid crystal display and provides easy to read
resistance (or resistivity) measurements.
In addition to those noted above:
ANSI/ESD S20.20 - Development of ESD Control Program When the Test Button is depressed, the LCD will indicate:
ESD ADV1.0 - Glossary of Terms • Temperature in degrees Fahrenheit
ANSI EOS/ESD S6.1- Grounding • Temperature in degrees Celsius
ANSI EOS/ESD S11.11 - Surface Resistivity • Humidity as percentage
• Surface resistance mantissa (with exponent displayed via
These documents can be obtained directly from the ESD LED, measurement in ohms)
Association, 7902 Turin Rd., Suite 4, Rome, NY 13440- Surface resistance ohm values are expressed with a
2069, (315) 339-6937 or www.esda.org. mantissa and exponent or power of the number. For
example, if "8" is illuminated by its LED and the LCD
Other standards are available from the agencies who displays a mantissa of "7.14", the measurement is 7.14 x
produce them. MIL-HDBK 263A, EIA-IS-5-A, ASTM-F-150, 108 ohms or 714,000,000 ohms
EN 100015, and EIA-625. If you need help in obtaining
these documents, please contact our customer service If surface is over 1012 ohms, the following will appear:
department. • "1____" on the LCD display indicate Overrange or that
the reading exceeds the display capabilities
Features
C. Test Button: This red button activates electrical power
A. LED Displays: Surface resistance exponent is displayed to the Meter. The exponent or power of the number is
via light emitting diodes illuminating 1/8" high number. displayed immediately with LED illuminating number. If "8"
There are 12 LEDs displaying surface resistance exponent is illuminated, the measurement is in the 108 or 10E8 ohm
measurement. They are color coded for quick checks:
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST - 90 Hudson Road, Canton, MA 02021-1407 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.desco.com

© 2005 DESCO INDUSTRIES INC.

TB-3014 Page 2 of 5 Employee Owned
 range. To make a measurement in accordance with ESD Power Requirements
S4.1, the button is to be depressed for 10-20 seconds for
The Meter is powered by two replaceable alkaline AA
the unit to make numerous readings and calculations.
batteries.
(Testing in accordance with ESD S4.1-1997 requires 15
seconds of electrification; in contrast, most analog type Battery Replacement
meters display measurements instantaneously.) The LCD
will display temperature (F), then temperature (C), then Depress buttons on both sides of bottom end cap of meter
relative humidity, and then the surface resistance mantissa. housing. Remove cap, press on right edge of protruding
For example, if the LCD displays a mantissa of "7.14", and battery door, unlatching it, and swing door open. Carefully
"8" is illuminates by its LED, the measurement is 7.14 x 108 replace batteries with alkaline Type AA. Polarity must be
ohms or 714,000,000 ohms. correct or damage may occur. Close battery door and re-
install bottom end cap on meter housing.
During the entire period, surface resistance exponent will be
displayed by LED illuminating number. Test Procedure
D. Override Test Range Voltage Button: When in the “up” General Guidelines:
position, during resistance portion of test, Meter will
• Use both 5# Electrodes for RTT
automatically switch to the correct voltage for the resistance
• Use one 5# Electrode and one lead to groundable point
range. LED will illuminate noting selected voltage. Con-
for RTG (note: groundable points are usually snaps
ductive material 105 ohms or less should be measured at 10
installed on the material or workstation)
volts. Dissipative material 106 or greater ohms should be
• Use optional Resistivity Attachment (removing leads &
tested at 100 volts. The button is a switch, which if
electrodes) for Resistivity measurements
depressed will override automatic voltage selection and test
• Ensure that item being measured is electrically isolated
will be performed at 10 volts regardless of resistance level.
(i.e. placed on an insulative surface) as Meter will
E. Jacks: One end of Test Leads has 3.5mm plug (fits measure lowest resistance path
Meter left jack). The 3.5mm plug is shielded (identified by • Ensure that test leads are separated or Meter may
insulated tip and barrel black lead) - see RTG test measure lower resistance path
procedure: Per ESD S4.1 "The sensing lead of the • When using 5# Electrodes:
resistance meter shall be connected to groundable point." • Place no closer than 2" from edge of surface being
One end of Test Lead has standard banana plug (fits 5# measured
Electrode jack). • Place no closer than 3" to any groundable point
• Place 5# Electrodes 10" apart for RTT
F. AA Battery Compartment. • Preferred placements include: most commonly used
G. Resistivity Parallel Attachment with Electrodes. surface portion, most worn, center, and furthest from
(optional Item number 19782) groundable point.
• For RTG, connect the sensing lead with shielded plug
Cleaning to groundable point
• If surface has sections (like floor tiles or garment panels),
Per ESD S4.1 "Clean the electrodes with a minimum 70%
for RTT place a 5 pound electrodes on different sections
isopropanol-water solution." Make sure conductive pads are
• Clean surface for Test Lab, but do not initially clean
dry prior to use.
surface for installed products (if fails, clean and retest).
See specific product test standard for test lab specimen
cleaning instructions. Per ESD S4.1 Worksurfaces "The Test Lab Test Procedure Guideline
test specimens and electrodes shall be cleaned twice with a For test lab use of ESD Worksurfaces, Floor Materials,
minimum 70% isopropanol-water solution using a clean, Footwear, Garments, or Seating, best advice is to follow
low-linting cloth each time." (Note: then conditioned for 72 procedures in applicable ESD Association standards (see
hours, minimum.) above) which include details regarding:
For installed product periodic testing, do not clean surfaces. • Cleaning (For example per S4.1 "The test specimens and
However, if any measurements lie outside acceptable range, electrodes shall be cleaned twice with a minimum 70%
then clean the surface and re-test. (Note: for worksurfaces, isopropanol-water solution using a clean, low-linting cloth
use Desco Reztore™ Antistatic Surface and Mat Cleaner each time). Allow to dry.
(item 10435) or other ESD cleaner not containing silicone. • Environmental chamber (For example per S4.1 control
Be sure the surface is dry before testing. relative humidity to 12 ±3% RH and 50 ±5% RH and
temperature to 23 ±1 degrees C)
Periodic maintenance - The area surrounding the cable • Specimen support surface (For example per S4.1 greater
jacks at the top end of the meter should be wiped with a than 1.0 x 1012 ohms such as PMMA, PTFE or
clean cloth moistened with alcohol to remove skin oils that polycarbonate)
will accumulate and affect the accuracy at high resistances. • Specimen Pre-Conditioning (For example per S4.1 at 23
The frequency of cleaning will depend on usage; once a ±1 degrees C; 3 specimens at 12 ±3% relative humidity
month would be a good starting point. Other items that for up to 72 hours minimum, and 3 specimens at 50 ±5%
should also be cleaned in this fashion are the cable jackets relative humidity for up to 72 hours minimum)
and the resistivity attachment, if included.
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST - 90 Hudson Road, Canton, MA 02021-1407 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.desco.com

© 2005 DESCO INDUSTRIES INC.

TB-3014 Page 3 of 5 Employee Owned
 • Reporting Test Results, for example per S4.1 Reporting • Press button and hold Test Button until measurement is
Test Results, Report: displayed
• Minimum, median and maximum readings for both • If the most used portion is not obvious, use two points
resistance-to-groundable point and point-to-point near the center of the surface
resistance in ohms at low relative humidity
• Minimum, median and maximum readings for both If measurement is outside acceptable limits, clean surface &
resistance-to-groundable point and point-to-point retest to determine if cause of failure is insulative dirt layer
resistance in ohms at moderate relative humidity or the ESD protective product. Note: Use an ESD cleaner
• Temperature containing no insulative silicone (i.e. Reztore™ Antistatic
• Relative humidity Surface and Mat Cleaner)
• Actual duration of conditioning
• Test equipment used

Periodic Checks of Installed Product Test

Procedure Guideline
Measure RTG Resistance to Ground
Test Procedure in accordance with ESD S4.1 paragraph 6.4 10
"
Periodic Worksurface Testing:
• Do not clean the surface
• Remove from the surface only those items that might
interfere with the test.
• ESD sensitive devices shall also be removed
• Clip the sensing test lead with shielded plug to
groundable point connected to ground Figure 4. Setting up for RTT testing.
• Use one 5# Electrode on other test lead and place
Electrode the farthest convenient point on the surface Reporting and Using Test Results
• Press button and hold Test Button until measurement is Different standards have different requirements; use
displayed requirements as specified in user's ESD control plan.
• Perform additional measurements placing Electrode on Examples are:
the most commonly used or most worn area
Per ESD 4.1 (worksurfaces), Report:
If measurement is outside acceptable limits, clean surface • RTG maximum and minimum values measured for
and retest to determine if cause of failure is insulative dirt resistance-to-ground
layer or the ESD protective product. Note: Use an ESD • RTT maximum and minimum values measured for point-
cleaner containing no insulative silicone (i.e. Reztore™ to-point resistance in ohms
Antistatic Surface and Mat Cleaner).
Per ESD 7.1 (floors) Report:
• RTG all values in ohms for resistance to ground
• RTT all values in ohms for point-to-point resistance
• Voltage level
• Test date
• Temperature
• Relative humidity
• Test equipment used
Summarize test data by reporting minimum, maximum,
median, and mean values obtained. Include a diagram
showing approximate electrode positions and ground
connections used.

Figure 3. Setting up for RTG testing. Recommended Frequency of Periodic Checks

of Installed Products
Measure RTT Resistance Between Two Points Note: "The frequency of periodic testing is normally
on the Surface specified in corporate operating procedures. …The
frequency of testing is driven by the amount of risk
• Do not clean the surface exposure that can occur between tests. For, example, what
• Remove from the surface only those items that might is the quantity of product handled between test periods?"
interfere with the test. (See ESD Handbook TR 20.20) However, a common guide
• ESD sensitive devices shall also be removed would be:
• Use two 5# Electrodes, place in the most commonly used • Worksurface - at least quarterly (see TR 20.20 paragraph
portion of the surface 10" apart (2" from any edge, 3" 5.3.1.13 Periodic Tests)
from any groundable point)
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST - 90 Hudson Road, Canton, MA 02021-1407 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.desco.com

© 2005 DESCO INDUSTRIES INC.

TB-3014 Page 4 of 5 Employee Owned
 • Footwear - "Incoming inspection on a lot sampling basis Test Switch: Press the red test button for 15-20 second
should be performed for all static control footwear." (see electrification period. Meter will immediately display surface
TR 20.20 paragraph 5.3.3.4 Testing) resistance exponent via LED. LCD will display temperature
• Floor - "The types of monitoring and type of equipment (both Fahrenheit & Celsius), then humidity, and after taking
are considerations. In some cases, a simple electrical numerous readings and making numerous calculations
resistance test with a megohmmeter may suffice. In display surface resistance mantissa.
others, a static charge generation test may be required."
(see TR 20.20 paragraph 5.3.4.13 Performance Note: Reporting test results, you may want to record the
Monitoring) resistance, humidity, temperature, and test voltage.
• Seating - "The recommended electrical resistance range
for seating is less than 1 x 109 ohms as tested in
Maintenance
accordance with ESD STM 12.1. This value should be Your Surface Resistance Test Kit will require little
during acceptance testing, installation and periodically maintenance, and there are no user serviceable parts. If
thereafter." (see TR 20.20 paragraph 5.3.5.3 Testing) your Meter requires service beyond cleaning the Electrodes
• Garments - "To maintain process control, it is imperative or replacing the batteries, please contact the factory.
that the garment be tested per ESD STM 2.1. The point
to point and sleeve to sleeve resistance test should be Calibration
*The
made." (see TR 20.20 paragraph 5.3.13.3.1.8 Periodic Surface Resistance Test Kit is calibrated to NIST
Testing) traceable standards. Most users require calibration annually.
Please call our Customer Service Department at 909-627-
Surface Resistivity 8178 (Chino, CA) or 781-821-8370 (Canton, MA) for details.
Theoretically Resistivity is 10 times greater than Resistance, In-house calibration can be performed by using 1% resistors
i.e. a material that measures 107 ohms RTT, Surface in each of the meter ranges. Simply attach the resistors to
Resistivity should measure 108 ohms/square.* the enclosed cords using grounding clips and recording the
meter display. Keep the cords separated. Should
Ref: ESD S11.11 paragraph 12.0 Conversion to Resistivity adjustment be necessary, it is recommended that the unit be
states, "When it is appropriate to convert a resistance returned to the factory as access to internal adjustments
obtained by this test method to an equivalent resistivity in requires special equipment and test cables.
ohms per square, multiply the resistance measurements
obtained by this method by 10. The conversion factor of 10 Specifications
is derived from the geometry of the electrode assembly."
Ranges: 1 x 103 - 1 x 1012 ohms @ 10 Volts
No conversion is required with the Surface Resistance Test complies with ESD-S4.1
Kit. The Meter incorporates provision to install optional 1x106 - 1x1012 ohms @ 100 Volts complies with ESD-S4.1
Resistivity Attachment which has parallel electrodes on Power Supply: Two AA alkaline batteries
bottom of the unit to make direct surface resistivity
measurements. These parallel electrodes allow for Accuracy is measured after normalizing the instrument
measurement of resistivity or when quick testing without the *
at 70-80 °F and 30-50% RH for a minimum of 4 hours.
use of 5 pound electrodes is desired.
*Note: Currently, there is discussion within the ESD Limited Warranty
Association if the proper unit of measurement of resistivity Desco expressly warrants that for a period of one (1) year from the date of purchase,
is ohms or ohms/square. S11.11-1993 uses ohms/square. Desco Test Kits will be free of defects in material (parts) and workmanship (labor). Within
the warranty period, the product will be tested, repaired, or replaced at Desco’s option,
Battery Life: Approximately 1,500 measurements free of charge. Call our Customer Service Department at 909-627-8178 (Chino, CA) or
781- 821-8370 (Canton, MA) for a Return Material Authorization (RMA) and proper shipping
Resistivity Electrodes: Two parallel conductive silicone instructions and address. 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 Desco
rubber electrodes (optional item) factory.Warranty repairs will take approximately two weeks.

External Electrodes: Two 5-pound (±2 oz) weighted If your unit is out of warranty call Customer Service at 909-627-8178 (Chino, CA) or 781-
electrodes, 2.5" in diameter, complies with ESD-S4.1 821-8370 (Canton, MA) for a Return Material Authorization (RMA) and proper shipping
instructions and address. Desco will quote repair charges necessary to bring your unit up
Display: One 3.5 digit .500" Liquid Crystal Display (LCD) to factory standards.
Display and seventeen Light Emitting Diodes (LED's) Warranty Exclusions
illuminate exponent numbers and function being performed. THE FOREGOING EXPRESS WARRANTY IS MADE IN LIEU OF ALL OTHER
PRODUCT WARRANTIES, EXPRESSED AND IMPLIED, INCLUDING
Accuracy: Resistance measurements within ±10% (E12 &
*
greater ±20%), complies with ESD-S4.1. Open circuit
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE WHICH ARE
SPECIFICALLY DISCLAIMED. The express warranty will not apply to defects or damage
voltages of 10 volts ± 5% and 100 volts ± 5% exceeds due to accidents, neglect, misuse, alterations, operator error, or failure to properly
maintain, clean or repair products.
requirements of ESD-S4.1
Limit of Liability
Meter Weight: 15.5 oz. In no event will Desco or any seller be responsible or liable for any injury, loss or damage,
direct or consequential, arising out of the use of or the inability to use the product. Before
Dimensions: 8"L x 4.3"W x 1.6"H using, users shall determine the suitability of the product for their intended use, and users
assume all risk and liability whatsoever in connection therewith.

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178 • Fax (909) 627-7449
DESCO EAST - 90 Hudson Road, Canton, MA 02021-1407 • (781) 821-8370 • Fax (781) 575-0172 • Web Site: http://www.desco.com

© 2005 DESCO INDUSTRIES INC.

TB-3014 Page 5 of 5 Employee Owned