### EARTH HiTESTER 3143, 3151

```EARTH HiTESTER 3143, 3151
Field measuring instruments
Ground resistance meter
Say goodbye auxiliary grounding
rods with the 3143.
3-electrode measurement on the 3151 gives greater precision!
Tangle-free
1
The 3143 requires no auxiliary grounding rods,
making measurement easy.
Presenting a next-generation ground
resistance meter
Grounding is increasingly important for the safe
operation and maintenance of communications
equipment and many other types of facilities. However,
in an urban environment where the ground is covered
with concrete or asphalt, conventional measurement
methods that require inserting auxiliary grounding
electrodes are difficult to use. The 3143 uses a
new measurement principle that makes auxiliary
grounding electrodes unnecessary, so it can be
used to measure ground resistance on paved roads.
Using the 3143
1. Wire as shown in the diagram.
2. Turn the rotary knob to measure.
As the rotary knob is turned, the lowest resistance value that is
displayed is the grounding resistance value.
String along the
ground (20m)
Return Earth
Rx
Features
■Auxiliary grounding rods are unnecessary, greatly
reducing time and effort.
Measurement can be done easily on concrete or asphalt
pavements.
A large digital display shows measured values.
■Resistant to dirt.
Dust resistance of parts such as the power switch and
measurement dial has been increased and durability has been
improved.
Measurement Principle of the 3143
The 3143 obtains ground resistance Rx by measuring the loop
impedance of the closed path that goes from the lead wire to
earth, then back to a return line which is strung along the surface
of the earth.
The drawing below shows an equivalent circuit, where Rx is
the ground resistance of the object being measured, C is the
capacitance of the return wire relative to ground, and L is the
inductance of the measurement cable.
By varying the frequency of the measurement signal source so
that LCR is serially resonant, the ground resistance Rx can be
determined as follows.
Rx = Vm / (Vc - Vm) × Ro
Here, Vc is the signal source voltage, Vm is the voltage between the
measurement terminals, and Ro is the signal source output resistance.
With the 3143 you turn the measurement knob to vary the signal
source frequency. As the knob is turned, the smallest value
that appears (the value at the resonance point) is the ground
resistance value Rx.
Wire
Return Wire
Ground being
measured
3143
Equivalent Circuit Model
Ground
3143
Equivalent Circuit At Resonance
The 3143 is most appropriate for measuring the ground
resistance of an individually grounded rod-shaped
electrode.
Convenient Features
Bar graph display makes it easy to find measured resistance.
Turn the rotary knob so that the graduations are centered.
Dust-resistant
switch
Large, easy to read LCD display
Easy-grip elastomer knob
Differences from the Previous Instrument (Model 3151)
Common ground resistance meters such as the 3151 measure the
resistance using a frequency between 500 Hz and several kHz.
The 3143 uses a frequency between 100 kHz and 1.5 MHz, close
to that of a lightning surge. Therefore, measurement errors can
result if the 3143 is used in situations such as the following. In
these instances, we recommend using Model 3151.
• Electrical grounding or mesh grounding.
• Electrical power equipment grounding.
• When the measurement point is located at a distance from the
insertion point of the grounding electrode.
2
Count on The 3151 for Dependable Measurements
The 3151 is a Standard Ground
Resistance Meter
Ground resistance measurement involves factors
that are not encountered during ordinary resistance
measurement, such as polarization of the earth, the
influence of grounding current due to leak current
and grounding voltage, and the influence of auxiliary
grounding resistance. The 3151 is able to make more
accurate measurements more safely under difficult
conditions because it uses the alternating current
potentiometer method to provide measurement
accuracy, and because it contains features such as
an auxiliary grounding resistance check feature and
measurement frequency switching.
Features
■ A ground resistance meter that meets EN standards
Its safety and reliability know no borders. Use it anywhere
with confidence.
■ Wide measurement range
Take measurements to 115% of the measurement range.
■ More stable measurement
Easily check the grounding condition of auxiliary grounding
rods for better accuracy. Further, the measurement frequency
switching lets you avoid influences such as that of high
frequency grounding current.
■ Simple measurement feature
Switch between "normal" and "simple" measurement modes
with the press of a button.
■ Overvoltage protection and alarm feature
If wires are incorrectly connected (as often happens during
simple measurement of commercial power supplies), safety is
provided by an alarm buzzer and overvoltage protection.
■ Resistant to dirt
Parts such as the measurement switches and measurement dial
have increased dust resistance and durability.
■ More convenient accessories
A cable winder ensures freedom from cable tangles, and a
convenient carrying case accommodates all measurement
materials.
Using the 3151
Normal Measurement (3 Electrode Method)
1.Wire as shown in the diagram.
2.Set the 2/3 electrode method switch to 3 electrode
measurement.
3.Check for grounding voltage in the grounding voltage
range.
4.Check the auxiliary grounding resistance values for C
and P in the auxiliary grounding resistance range.
5.Measure using the appropriate resistance range.
While pressing the measurement button, turn the resistance
dial knob and read the resistance when the galvanometer
reaches a balance.
C
E
P
E
C
Rx
5~10m
5~10m
Simple Measurement (2 Electrode Method)
1.Wire as shown in the diagram. (Example of power
supply grounding line connection)
2.Set the 2/3 electrode method switch to 2 electrode
measurement.
3.Check for grounding voltage in the grounding voltage
range.
4.Take measurements, choosing either ×10 or ×100.
While pressing the measurement button, turn the resistance
dial knob and read the resistance when the galvanometer
reaches a balance. (Measured value = Rx + Ro.)
AC 250 V max
E
Convenient Features
P
C
Rx
Ro
5M
minimum
Shock resistant
taut band meter
Overvoltage protection and alarm buzzer
Prevents damage due to incorrect connection during simple measurement
(commercial power supply grounding), and warns of incorrect connection by buzzer.
The resistance measurement is
increased to 115% of range
Accessories for Greater Convenience
High durability
measurement switches
with dust-resistant
construction
Auxiliary resistance (P/C) check feature
Check the ground condition of auxiliary grounding resistance,
which can cause measurement error.
• Convenient cable winder for total away the
measurement cable.
• Carrying case holds everything for total
portability.
Easy-grip elastomer knob
Measurement method and frequency switching switches
Push a button to select simple measurement (two electrode method).
And, a feature to select the measurement frequency in order to reduce the influence
of grounding voltage or grounding current due to high power supply frequency.
3
3143 Specifications
3151 Specifications
Measurement
Item
Measurement Range
Accuracy
Grounding
Resistance
20.0 to 49.9 Ω
± 10% rdg.
50.0 to 500.0 W
± 5% rdg.
Measurement
Item
Grounding
Resistance
(Temperature and humidity: Within rated operating temperature and humidity range.)
●Display: 4-digit LCD, values above 999.9 Ω displayed as "OF"
●Influence of grounding voltage: ± 5% rdg. for 0 to 10 V
●Principle of operation: voltage comparison method
(Measurement of voltage at loop impedance serial resonance)
●Open circuit voltage: AC 1 Vp typ
●Measurement current: AC 3.6 mA max (With terminals shorted)
●Measurement frequency: 100 kHz to 1.5 MHz
●Features:
• Energy saving mode: after 3 minutes with no operation, displays
"HOLD" and enters the standby state
• Resonance indicator: bar graph indicator shows approximate
location of resonance point
• Battery check: battery light flashes when the power supply voltage
drops
●Operating temperature and humidity:
0 to 40˚C, 80% rh maximum (no condensation)
●Storage temperature and humidity:
-10 to 50˚C, 80% rh maximum (no condensation)
●Applicable standards:
• Safety: EN61010-1 + A2, overvoltage category I, pollution level 2
• EMC: EN61326-1 + A1 class B
●Power supply: LR6 alkaline battery × 4
●Operating time: 8 hours continuous (23˚C reference value)
●Approximate dimensions and weight:
155 (W) × 98 (H) × 49 (D) mm (not including projections),
380 g (main unit only)
●Accessories:
MEASURING CABLE 9265
(black 1 m, red 20 m, one each; CABLE WINDER 9216 × 1)
PORTABLE CASE 9338
Measurement Range
Nominal
Deviation
10 Ω (0 to 11.5 Ω)
± 2.5 % f.s.
100 Ω (0 to 115 Ω)
± 2.5 % f.s.
1000 Ω (0 to 1150 Ω)
± 2.5 % f.s.
30 V (0 to 30 V)
± 3.0 % f.s.
Grounding
Voltage
(Temperature and humidity: 23˚C ± 5˚C, 80% rh maximum)
(100Ω/1000Ω ranges only with 2 electrode measurement)
●Influence of auxiliary grounding resistance:
± 5% for a fluctuation of 0 to 5 kΩ
●Influence of grounding voltage:
± 2% for 0 to 5 V
± 5% for 0 to 10 V (for 50/60 Hz)
± 5% for 0 to 3 V (for DC, 162/3, 400 Hz)
●Influence of power supply voltage:
within nominal deviation for DC 6 to 10 V
●Operating method: AC potentiometer method
●Open circuit voltage: AC 50V max
●Measurement current:
AC 15 mA max (AC 3 mA max when using the two electrode method)
●Measurement frequency:
575 Hz (with 3a or 2a selected) or 600 Hz (with 3b or 2b selected)
●Operating temperature and humidity:
0 to 40˚C, 80% rh maximum (no condensation)
●Storage temperature and humidity:
-10 to 50˚C, 80% rh maximum (no condensation)
●Applicable standards:
• Grounding resistance meter: EN61557-5
• Safety: EN61010-1 + A2 / EN61010-2-031, overvoltage category II,
pollution level 2
• EMC: EN61326-1+A1
●Environment protection: IP40 (EN60529:1991)
●Overvoltage protection:
AC 250 V, 1 minute (between E - P (S), E - C (H) terminals)
●Power supply: R6P manganese battery × 6, or LR6 alkaline battery × 6
●Operating time: Approx 350 operations (using R6P battery)
Approx 1100 operations (using LR6 battery)
(30 seconds measurement / 30 seconds off condition)
●Approximate dimensions and weight:
164 (W) × 119 (H) × 88 (D) mm (not including protrusions),
800 g (main unit only)
●Accessories:
AUXILIARY GROUNDING RODS 9214 × 2
MEASURING CABLE 9215
(black 5 m, yellow 10 m, red 20 m, one each; CABLE
WINDER 9216 × 3)
PORTABLE CASE 9393
●Optional accessory
EARTH NETS 9050 (set of two)
Use in places where auxiliary grounding rods cannot be inserted
(but where water can penetrate)
HIOKI (Shanghai) Sales & Trading Co., Ltd. :
1608-1610 Shanghai Times Square Office, 93 Huai Hai Zhong
TEL +86-21-6391-0090/0092 FAX +86-21-6391-0360
E-mail: [email protected]
81 Koizumi, Ueda, Nagano, 386-1192, Japan
TEL +81-268-28-0562 / FAX +81-268-28-0568
E-mail: [email protected]
HIOKI USA CORPORATION :
6 Corporate Drive, Cranbury, NJ 08512 USA
TEL +1-609-409-9109 / FAX +1-609-409-9108
E-mail: [email protected]
DISTRIBUTED BY
Beijing Office :
A-2602 Freetown, 58 Dong San Huan Nan Road
Beijing, P.R.China POSTCODE: 100022
TEL +86-10-5867-4080/4081 FAX +86-10-5867-4090
E-mail: [email protected]
Guangzhou Office :
Room A-3206, Victory PlazaServices Center, No.103,