Desco TB-3076 User manual

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Website: Desco.com
TB-3076 Page 1 of 8 © 2019 DESCO INDUSTRIES INC
Employee Owned
Digital Surface Resistance Meter Kit
Installation, Operation and Maintenance
Description
The Desco 19290 Digital Surface Resistance Meter
Kit is an instrument designed to measure resistance
point-to-point (Rtt) or surface to ground (Rtg).
Its test functions include:
• Resistance measurement accuracy of ±10%
(±20% accuracy for 1 x 1012 ohms and greater)
• Resistance range of <1 x 103ohms to >1 x 1012
ohms
• Under load voltages of 10 and 100 volts ±5%
• Electrification period of approximately 15 seconds
The Digital Surface Resistance Meter also measures
ambient temperature and relative humidity. Up to 100
measurements may be stored and recalled from the
meter's internal memory. This includes the resistance
value, temperature, relative humidity and test voltage at
the time of the measurement.
May 2019
The Surface Resistance Meter is referenced and
designed to be used to make measurements in
accordance with the test procedures in:
• Compliance Verification - ESD TR53 - Resistance
Measurements
• Worksurfaces - ANSI/ESD S4.1 Worksurfaces
• Floors - ANSI/ESD S7.1- Resistive Characterization
of Materials Floor Materials
• Foot Grounders - ESD SP9.2 - Foot Grounders
Resistive Characterization
• Garments - ANSI/ESD STM2.1 Garments
Seating - ANSI/ESD STM12.1- Seating - Resistive
Measurement
• Floor/Footwear - ANSI/ESD STM97.1 - Floor
Materials and Footwear- Resistance Measurement
in Combination with a Person
“A Compliance Verification Plan shall be established
to ensure the Organization’s fulfillment of the technical
requirements of the ESD Control Program Plan. Process
monitoring (measurements) shall be conducted in
accordance with a Compliance Verification Plan that
identifies the technical requirements to be verified, the
measurement limits and the frequency at which those
verifications shall occur. The Compliance Verification
Plan shall document the test methods and equipment
used for process monitoring and measurements. If the
test methods used by the Organization differ from any
of the standards referenced in this document, then
there must be a tailoring statement that is documented
as part of the ESD Control Program Plan. Compliance
verification records shall be established and maintained
to provide evidence of conformity to the technical
requirements. The test equipment selected shall be
capable of making the measurements defined in the
Compliance Verification Plan.” (ANSI/ESD S20.20
section 7.3)
Made in the
United States of America
TECHNICAL BULLETIN TB-3076
Figure 1. Desco Digital Surface Resistance Meter Kit

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Website: Desco.com
TB-3076 Page 2 of 8 © 2019 DESCO INDUSTRIES INC
Employee Owned
The Digital Surface Resistance Meter and its
accessories are available in the following item numbers:
Item Description
19290 Digital Surface Resistance Meter Kit
19291 Digital Surface Resistance Meter
19292 Carrying Case
19293 Electrode Spacers, 10" and 36"
19294 Test Leads
19295 Handheld Electrode
19296 Measurement Location Labels, 25 Pack
50003 Replacement 5 lbs. Electrodes
50004 Replacement T-Handles for 5 lbs. Electrodes
50005 Concentric Ring Probe
Packaging
19290 Digital Surface Resistance Meter Kit
1 Digital Surface Resistance Meter
2 Test Leads, 5' Length
2 5 lbs. Electrodes
1 Electrode Spacer, 10"
1 Electrode Spacer, 36"
4 AA Alkaline Batteries
1 Ground Plug Adapter
1 Gator Clip
25 Measurement Location Labels
1 Plastic Carrying Case
1 Certificate of Calibration
19291 Digital Surface Resistance Meter
1 Digital Surface Resistance Meter
4 AA Alkaline Batteries
1 Certificate of Calibration
Figure 3. Desco 19291 Digital Surface Resistance Meter
Figure 2. Desco 19290 Digital Surface Resistance Meter
Kit

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Website: Desco.com
TB-3076 Page 3 of 8 © 2019 DESCO INDUSTRIES INC
Employee Owned
Features and Components
Digital Surface Resistance Meter
A. Test Jacks: The shielded black test lead’s male
SMA connector connects into the meter's female SMA
connector, and the red test lead’s banana plug connects
into the meter's banana jack.
B. Exponent LEDs: These LEDs indicate the surface
resistance exponent value. They are color coded for
resistance decade quick checks.
Exponent Color
<3, 3 Yellow
4, 5, 6, 7, 8, 9, 10 Green
11, 12, >12 Red
(i.e. 8 = 10⁸ohms or 100,000,000 ohms).
C. OLED Display: Displays the temperature, relative
humidity, battery life, test voltage and resistance
measurement.
D. Power Switch: Slide the switch to the left to power
the meter OFF. Slide the switch to the right to power the
meter ON.
E. Black Pushbuttons: Each black pushbutton
corresponds to the prompts on the bottom-left and
bottom-right of the display. These buttons are used to
access the Settings and Memory Recall menus and
scroll up and down between menu options.
Figure 4. Digital Surface Resistance Meter features and
components
C
B
D
EE
G
F
A
F. Red Pushbutton: Corresponds to the prompts
located in the bottom-center of the display. This button
is used to perform tests and select menu options. Press
and hold this button when in the Settings and Memory
Recall menus to exit and return to the home screen.
G. Battery Compartment: Open this compartment to
install the four AA alkaline batteries needed to power
the meter. Replace the batteries once the battery icon
on the display is empty.

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Website: Desco.com
TB-3076 Page 4 of 8 © 2019 DESCO INDUSTRIES INC
Employee Owned
Home / Test Results Screen Memory Recall Menu
H
J
L
I
K
Figure 5. Home / Test Results screen
H. Battery Life Indicator: Displays the approximate life
of the meter's 4 AA alkaline batteries.
I. Relative Humidity: Displays the relative humidity.
J. Test Voltage: Displays the test voltage used to
complete the measurement.
K. Temperature: Displays the ambient temperature.
L. Resistance Measurement: Displays the resistance
measurement in ohms (Ω).
Settings Menu
M
N
Figure 6. Settings menu
M. Firmware Revision: Displays the meter's firmware
revision.
N. Temperature: Sets the unit of measurement for
temperature to either Fahrenheit (ºF) or Celsius (ºC).
O. Stabilization Mode: Sets the meter's electrification
period setting to either Auto and Fixed Stabilization.
Auto - Enables a 15-second electrification period when
the measured resistance is 1 x 1010 ohms or greater to
maintain test accuracy.
Fixed - Complies with ANSI/ESD S4.1 and enables a
15-second electrification period when the measured
resistance is 1 x 106ohms or greater.
P. Beep: Enables and disables the audible beep when
the meter's pushbuttons are pressed.
Q. Erase all memory: Erases all stored measurement
transactions saved in the meter's memory.
R S
Figure 7. Settings menu
R. Memory Slot Number: Indicates the memory slot
number.
S. Resistance Measurement: Indicates the resistance
measurement value for the respective memory slot.
Operation
General Guidelines
Use both 5-pound electrodes for Resistance
Point-to-Point (Rtt) measurements.
Use one 5-pound electrode, and connect the black
test lead to ground for Resistance-to-Ground (Rtg)
measurements.
Ensure that the item being measured is electrically
isolated (placed on an insulative surface). The meter will
measure the lowest resistance path.
The meter will automatically switch its test voltage from
10V to 100V when the measured resistance is 1 x 10⁶
ohms or greater to meet the test procedure outlined in
ESD TR53.
Minimize crossing the test leads when possible.
When using 5-pound electrodes:
• Place them no closer than 2" from the edge of the
surface being measured.
• Place them no closer than 3" to any groundable
point.
• Place them about 10" apart from each other for Rtt
measurements of a worksurface.
• Place them about 3' apart from each other for Rtt
measurement of a floor.
Preferable electrode placements include:
• Most commonly used area of a surface
• Most worn area
• Center of surface
• Furthest area from a grounded point
If the surface to be measured has sections (i.e. floor
tiles, garment panels), place the 5-pound electrodes on
different sections for Rtt measurements.
Clean the material’s surface for test lab measurements,
but do not clean the surface for materials that are
already installed. Only clean and re-test the installed
material if failure occurs.
O
P
Q

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Website: Desco.com
TB-3076 Page 5 of 8 © 2019 DESCO INDUSTRIES INC
Employee Owned
Measure Resistance-to-Ground (Rtg)
Test Procedure in accordance with ANSI/ESD S4.1
section 6.4 Periodic Worksurface Testing:
1. Do not clean the surface.
2. Remove from the surface only those items that
might interfere with the test. ESD sensitive devices
shall also be removed.
3. Connect the black test lead to a grounded point.
4. Connect the red test lead to one 5-pound electrode,
and place the electrode on the furthest convenient
point on the surface.
5. Push the red pushbutton to perform a measurement.
Should the 15-second electrification period appear,
it may be bypassed by pushing the red pushbutton
a second time.
6. Push the right black pushbutton to save the
measurement, and apply an included measurement
location label if desired.
7. Perform additional measurements by placing the
electrode on the most commonly used or worn area.
Figure 10. Using the Desco 19295 Handheld Electrode
to measure Floor Materials and Footwear - Resistance
Measurement in Combination with a Person (ANSI/ESD
STM97.1)
Figure 9. Applying a measurement location label to the
edge of a workstation
Figure 11. Using the Desco 19295 Handheld Electrode
Figure 8. Measuring the Resistance-to-Ground (Rtg) of a
worksurface mat

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Website: Desco.com
TB-3076 Page 6 of 8 © 2019 DESCO INDUSTRIES INC
Employee Owned
Maintenance
The Digital Surface Resistance Meter requires little
maintenance. There are no user serviceable parts. If the
meter requires service beyond cleaning the electrodes
or replacing the batteries, please contact the Desco
Customer Service.
Battery Replacement
Replace the batteries once the battery life indictator
is empty. Open the compartment located on the back
of the meter to replace the batteries. The meter uses
four AA alkaline batteries. Ensure that the batteries’
polarities are oriented in the correct fashion to avoid any
possible circuit damage.
Cleaning the Digital Surface Resistance Meter
The area surrounding the test 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 5 lbs. 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)
Figure 13. Measuring the Resistance Point-to-Point (Rtt)
of oor materials
Measure Resistance Point-to-Point (Rtt) on the
Surface
1. Do not clean the surface.
2. Remove from the surface only those items that
might interfere with the test. ESD sensitive devices
shall also be removed.
3. Connect both test leads to both 5-pound electrodes,
and place the electrodes on the most commonly
used area of the surface. Use the 10" electrode
spacer to space them 10" apart from each other.
The electrodes should also be 2" away from any
edge and 3" away from any grounded point. If the
most used area is not obvious, use two points near
the center of the surface.
4. Push the red pushbutton to perform a measurement.
Should the 15-second electrification period appear,
it may be bypassed by pushing the red pushbutton
a second time.
Figure 12. Electrication period timer
5. Push the right black pushbutton to save the
measurement if desired.
6. Perform additional measurements by placing the
electrode on the most commonly used or worn area.
Figure 12. Measuring the Resistance Point-to-Point (Rtt)
of a oor tile

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Website: Desco.com
TB-3076 Page 7 of 8 © 2019 DESCO INDUSTRIES INC
Employee Owned
Calibration
Frequency of recalibration should be based on the
critical nature of those ESD sensitive items handled
and the risk of failure for the ESD protective equipment
and materials. In general, Desco recommends that
calibration be performed annually.
In-house calibration can be performed by using ±1%
tolerance resistors in each of the meter's decade
ranges. Connect the resistors to the test leads using
clips and record the meter’s display. Minimize crossing
the test leads when possible. Contact Desco Customer
Service should adjustments be necessary. Special
equipment is required to adjust the meter.
Required Equipment
• Digital Multimeter (±1.25% accuracy @10VDC and
100VDC)
• Resistance Decade Box with a range of 10³to 1012
ohms (±2% accuracy @ 10³to 1010 ohms; ±5%
accuracy @ 1011 to 1012 ohms)
• Thermometer (±1°F accuracy)
• Relative Humidity Meter (±2% accuracy)
• 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 10³or 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.
Normalization of the Meter
The temperature inside the testing area needs to be
75°F ±3°F (23.9°C ±1.7°C) at 40% to 60% relative
humidity. The meter needs to stay at a temperature of
75°F ±3°F (23.9°C ±1.7°C) for approximately 1 hour for
proper readings. The meter cannot be normalized inside
objects, enclosed boxes, containers or cases. The
temperature inside an enclosed case will differ from the
outside temperature. These cases will act as insulators.
The meter must remain stationary in the testing area
for about 1 hour without any significant changes to the
temperature.
NOTE: Accuracy is measured after normalizing the
meter for a minimum of 1 hour.
Calibration Verification Procedure
1. Use only the test leads that were supplied with the
meter.
2. Use 99% isopropyl alcohol to clean the two test
jacks located at the top of the meter. Oil from
human fingers can affect the accuracy of the meter.
3. Connect the test leads to the test jacks located at
the top of the meter. Connect the opposite end of
the test leads to a DC voltmeter.
4. Press the red pushbutton. The measured voltage
should start at 10V ±5% and increase to 100V ±5%
at the end of the test cycle.
5. Connect the test leads to the Resistance Decade
Box. Apply the load resistance values indicated in
the table below. The meter should display accuracy
within ±10% of the loaded resistance value.
Load
Resistance (Ω) Accuracy
Display
Value
Exponent
LED
1 x 1012 +20% 1.20 x 1012 12
-20% 8.00 x 1011 11
1 x 1011 +10% 1.10 x 1011 11
-10% 9.00 x 1010 10
1 x 1010 +10% 1.10 x 1010 10
-10% 9.00 x 1009 9
1 x 109+10% 1.10 x 1009 9
-10% 9.00 x 1008 8
1 x 108+10% 1.10 x 1008 8
-10% 9.00 x 1007 7
1 x 107+10% 1.10 x 1007 7
-10% 9.00 x 1006 6
1 x 106+10% 1.10 x 1006 6
-10% 9.00 x 1005 5
1 x 105+10% 1.10 x 1005 5
-10% 9.00 x 1004 4
1 x 104+10% 1.10 x 1004 4
-10% 9.00 x 1003 3
1 x 103+10% 1.10 x 1003 3
-10% <1.0 x 1003 <3

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Website: Desco.com
TB-3076 Page 8 of 8 © 2019 DESCO INDUSTRIES INC
Employee Owned
Specifications
Resistance Ranges 1 x 103to 1 x 106ohms @ 10
Volts, complies with ANSI/
ESD S4.1
1 x 106to 1 x 1012 ohms @
100 Volts, complies with
ANSI/ESD S4.1
Resistance Accuracy
(@ 23ºC, 40% R.H.)
Resistance measurements
within ±10% (±20% accuracy
for 1 x 1012 ohms and
greater), complies with
ANSI/ESD S4.1. Under load
voltages of 10 Volts ±5%
and 100 Volts ±5% exceeds
requirements of ANSI/ESD
S4.1
Temperature Accuracy ±10%
Relative Humidity
Accuracy
±10 integers
Power Supply 4 AA alkaline batteries
Battery Life Approximately 1,500
measurements
Display OLED, 2.7" diagonal, 128 x
64 pixel resolution
Memory Capacity 100 measurements
Operating Temperature 41ºF to 85ºF (5ºC to 30ºC)
Environmental
Requirements
Indoor use only at altitudes
less than 6500 ft. (2 km)
Maximum relative humidity of
80% up to 85°F (30°C)
Dimensions
(meter)
3.94" x 8.27" x 1.26"
(100 mm x 210 mm x 32 mm)
Dimensions
(carrying case)
15.0" x 14.5" x 3.5"
(381 mm x 368 mm x 89 mm)
Weight
(meter with batteries)
0.9 lbs (0.4 kg)
Weight
(populated carrying
case)
13.0 lbs (5.9 kg)
Country of Origin United States of America
Limited Warranty, Warranty Exclusions, Limit
of Liability and RMA Request Instructions
See the Desco Warranty -
Desco.com/Limited-Warranty.aspx