Hanchen TRONOVO TR7800 User manual

Hanchen Instrument
TR7800 Surface Resistance Tester
Megohmmeter

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Introduction
The TR7800 megohmmeter is a simple tester for measuring surface
resistivity. The device has two parallel electrodes on the back. It is
suitable for testing according to ASTM-D-257. If it is tested
according to DIN EN 015/1 standard, it uses circular electrodes
(optional). The instrument is suitable for all aspects of material
production, including engineering maintenance, quality
control,inspection material, manufacturing and research.It is also
used in anti-static mats, floors, wristbands, work clothes, footwear,
bags, turnovers and other anti-static performance evaluation tests.
The instrument has high measurement accuracy, simple operation,
and convenient portability. It is an ideal choice for auditing and
measuring surface resistance and point-to-point resistance.
Decimal conversion table
103= 1 KΩ
104= 10 KΩ
105= 100 KΩ
106= 1 MΩ
107= 10 MΩ
108= 100 MΩ

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109= 1000 MΩ
1010= 10,000MΩ
1011= 100,000 MΩ
1012= 1,000,000 MΩ
The test value is displayed on the LCD display. Unlike meters with
LED that only indicate decimal measurements, the TR7800 will
display the actual value. 27 megohms (2.7x107) shows 2.7e07 ohms
/ square.
Test voltage
The test voltage is 10v and 100v. According to ESDA standard S4.1,
S7.1 and S11.11, for conductive surfaces less than 106, 10v should
be selected, and for materials of 106 or greater, 100v should be
selected. If the meter cannot automatically apply the correct voltage,
it is recommended that you manually change to the correct setting.
Use the switch on the front of the meter to change the voltage
setting.
According to the definition of the ESD Association, the values are
expressed as follows.

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Notes on Voltage
In the past, resistivity or resistance measurements were based on
ASTM D264, ASTM 991, NFPA 56A or NFPA 99 test standards,
which required 500V or 1000V voltage. But it posed a safety
problem for the people who were testing. ESDA standardizes the
testing process so that lower voltages can be used within a specific
range. TR7800 instruments use 9V batteries, but some instruments
with 9V batteries can not guarantee the accuracy required for testing,
especially for some impedance values greater than 107; TR7800 has
a transformer to convert the 9V into 10V or 100V and apply constant
charge throughout the voltage range. The accuracy depends on the
applied voltage, temperature and humidity.
Temperature and Humidity
Because humidity and temperature will affect the electrical
properties of the tested materials: low temperature and humidity will
increase resistance and slow down dissipation time.
Under high humidity conditions, a thin layer of water will condense

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on or be absorbed by the surface of the object to be measured. This
hygroscopicity increases the conductivity of the material, especially
for those materials with strong water absorption.
At high temperatures, the mobility of free electrons increases, thus
increasing the conductivity of materials, especially those of carbon
black, metal oxides, metals and other materials.
At low temperatures, internal stresses occur in materials, resulting in
an increase in the distance between conductive materials, thus
increasing the resistance value. Therefore, it is necessary to know
the temperature and humidity.
Recording Data
ASNI/ESDA Association and European CECC recognize the impact
of environmental conditions on measurement, so they require that
temperature and humidity should be recorded in their standards. If a
material is measured under high humidity and all measurement
requirements are passed, but when customers receive the material
and use it at low temperature and low humidity, it is possible that the
material cannot reach the requirement. Upon request, this will
inevitably lead to the return loss.
In ESD STM4.1 working surface-6.2.4 resistance measurement
section and ESD S7.1-1994 material impedance parameters, ground

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material 5.2.4 and 5.3.3 all require reporting temperature and
humidity while measuring.
Calibration
It is recommended that it be tested once a year. TR7800 instrument
supports third-party inspection agencies to re-examine (payment
item).
Internal Probe Measurement
Parallel electrode method conforms to ASTM-D-257 standard.
Horizontally place two conductive rods on the surface of the tested
object to quickly measure the resistivity of flat materials. Of course,
the temperature and humidity values should be written in the report.

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Exploration
When measuring between two parallel electrodes of the instrument,
the instrument will indicate the surface resistivity of the material be
measured.
A. Before testing, make sure that the surface to be tested is clean and
free of contaminants.
B. To measure in a new environment, the instrument needs to be
adapted for more than half an hour.
C. Place the instrument on the surface of the product to be tested.

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When measuring, the instrument must remain stationary and not be
moved.
D. Move the switch to the desired test voltage position, 10 or 100
volts, depending on the target range of the material.
E. Hold down the test button and apply approximately 5 pounds of
force. The display will show humidity and temperature. After about
ten seconds, the meter will display the surface resistivity in ohms per
square.
The meter will continuously update the display while the button is
held down. When the button is released, the last reading will be
displayed for about 20 seconds.
External Probe Measurement
When measuring with a 5 lb external probe, the tester will indicate
the resistance of the material in ohms.

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The resistance point-to-point (RTT) and grounding resistance (RTG)
can be measured by connecting the probe to the socket of TR7800.
The heavy hammer probe can be used to meet various standards,
including ANSI / ESDA STM4.1, ANSI / ESDA S7.1 material
impedance and floor material for measuring the resistance of
working surface.
After the inspection, please pull out the cable and put the probe into
the protective box. If the cable is not pulled out, the instrument
socket will become inelastic.
Resistance Point to Point (RTT)
RTT measurements can be used to evaluate floors, chairs, trolleys,

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working surfaces and other ESD control materials and products.
Procedure changes and sample preparation are related to the distance
of the 5-lb probe, and the correct test procedures and standards
should be selected according to the need.
A. Insert the audio plugs of the two test lines into the two jacks of
the meter and connect the other end of the two lines to two 5-pound
heavy probes.
B. Place two probes on the surface of the object to be measured
according to the test procedure or standard.
C. Press the test button and the value will be displayed on the LED.
The instrument will select the correct voltage (10V or 100V)
according to the measured value.

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D. Be careful not to touch the probe or lead when measuring, and
avoid overlap of lead, so as to make the reading more accurate.
RTT Example (Dissipative Floor Measurement)
Daily measurement is an important part of ground maintenance
when the surface is coated with consumable materials. Any ground
problems can be easily found by this method. The preservation of
temperature, humidity and electrical performance test records can
provide reference for maintenance of the ground. A good
preservation record can ensure the discovery and maintenance of the
ground in time.
In order to get the average measurement value of a ground, a 4’ * 4’
part and five test points (one at a time) need to be drawn in a square
area. Each side of the square and the diagonal line through the center
must be measured once (as shown below).
In each point-to-point (RTT) test, the 5-lb probe must be 36 inches
(36 inches/91.4 cm) away, connected to the test line and instrument,
and connected to a 5-lb probe at the end of each line (note the
distance of 36 inches above). Press the measurement button and hold
it until a value is displayed.

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(RTG) Point-to-Ground Resistance
Measurement Method
RTG measurements can be used to evaluate flooring, chairs, trolleys,
working surfaces and other ESD control materials and products.
Recorded test results of temperature, humidity and electrical
performance can provide reference.

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RTG Example (Dissipative Floor Measurement)
For ground resistance measurements, S7.1 requires a minimum of 5
test points for 5,000 square feet. Connect the cable of the external
probe to the instrument.
Connect a 5-lb probe to a cable and place the probe on the ground to
be tested. Then connect an alligator clamp to another cable well and
connect it to a ground or grounded point (RTGP). If you use a
ground adapter, please insert a banana plug into the adapter.

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RTG Example (Dissipative Table Mat
Measurement)
A. Use point-to-ground resistance measurement to measure a work
place. First connect the first cable to the instrument and connect a
5-lb probe. Then put the probe on the working table. Then connect
the instrument and grounding point with the second cable. If
connected to a point which can be grounded, the result is the
resistance of the point can be grounded (RTGB) not ground
resistance (RTG). Please use crocodile clips if necessary.
B Press the "Test" button and the value will be displayed on the LED.
When measuring, we should pay attention not to touch the probe or
lead and avoid overlap of lead, so that the reading can be accurate.
C. Resistance value is Ohm. Temperature and humidity should also
be taken into account when recording the test value, because the
environment will affect the test results.

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Volumetric Resistance Measurement
Volumetric Resistance Measurement is an important data for passing
the electrical property test of the material
A. Connect one end of the banana test lead to the instrument socket.
Connect the other end of the test coil wire to the 5-lb probe.
B. Place the sample material on a conductive metal plate (such as
stainless steel). Place a 5-lb probe on the material so that the material
is sandwiched between the probe and the metal plate. (See below)
C. Place the second 5-lb probe on the conductive metal plate.
D. Press the "Test" button and the value will be displayed on the

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LED. (Volumetric resistance in ohms-centimeters)
Calibration instructions
Please note that the calibration method is performed by the
following methods, and if verification cannot be achieved, it should
be returned to the supplier.
1. Range of 10 to 10 impedance bridge with accuracy of 1%, high
precision temperature and humidity meter
2. Open the meter cover, Be careful not to damage the two wires
connected to the power switch on the circuit board.
3. Find the three correction regulators on the lower right side of the
circuit board.

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4. Keep the meter under ambient conditions for at least half an
hour, and start the test after self-balancing.
5. Connect TR7800’s one end of the cable that comes with the meter
to a crocodile clip, and the other end to the banana plug.
6. Insert a 3.5mm long plug into the meter's socket.
7. The top one is humidity. The middle one is the resistor. The
bottom one is temperature. Use a small screwdriver to complete the
adjustment. The clockwise direction is to increase the value, and the
counterclockwise direction is to decrease the value.
8. Press the power button to calibrate the resistance value, humidity,
and temperature for comparison.
9. Release the power button, and slowly adjust the corresponding
adjustment regulator.
10. Press the power button again and observe the LCD screen. 12. If
you need to recalibrate, you can press the power switch and adjust
the corrector again.
10V gear accuracy 100V gear accuracy
103-104+/- 9% @ RH <90% 106-108+/- 5% @ RH <90%
104-108+/- 5% @ RH <90% 109-1010 +/- 9% @ RH <60%
108-109+/- 9% @ RH <90% 1010-1011 +/-15 % @ RH <50%
109-1010 +/- 25% @ RH <60% 1011-1012 +/- 25% @ RH <40%
Temperature and humidity accuracy

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Temperature ± 1.5 ℃@ <37.7℃
Humidity ± 8% RH @ <70%
Testing Equipment
*Decimal resistance box
* Test lead
A range from 1kΩ (103) to 999,999 MΩ (1012) is needed.
Connect the test lead from the decimal resistance box to the test
probe of the tester, set the decimal box to a fixed resistance, and then
press and hold the test button of the meter to compare the resistance
set by the decimal box with the resistance value displayed by the
instrument to verify the accuracy of the instrument.
Please note that the instrument has no internal components need to
be adjusted, so you can verify the calibration by using the above
process. If verification cannot be achieved, the instrument should be
returned to the supplier.

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TR7800 Resistivity Measuring Instrument
TR7800 is a lightweight pocket-type auto-range surface resistivity
measuring instrument. It is used to measure the impedance or
resistance of all conductive, antistatic and electrostatic discharge
surfaces.
Using Parallel Electrodes
Suitable for testing according to DIN EN100 015/1 and ASTM D257
standards.
Use with Heavy Hammer Kit (Purchased Separately)
It is suitable for testing according to IEC 61340-4-1, ANSI/ESDA
STM 4.1 and ANSI/ESDA S7.1 standards.
TR7800 resistivity meter includes
* Tester
* Two telescopic connectors
(audio plug to banana plug)
* Factory calibration certificate，certificate
Optional heavy hammer kits
includes
* Two 5-lb probes
* Sponge lined portable protective box
Measurement range
* Resistivity: 103-1012 Ohm/Square
* Resistance: 103-1012 Ohms
* Relative humidity：10%-90%RH
* Temperature: 0 - 37.7℃
* Measuring Voltage: 10V and 100V

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※Our Brand: Hanchen
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