ESCO Technologies ETS-Lindgren HI-3702 User manual

Model HI-3702
Clamp-On Induced Current Meter
User Manual
PN: #H-600070
August, 2022
Rev J
ets-lindgren.com

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ETS-Lindgren Inc. reserves the right to make changes to any products herein to improve functioning or
design. Although the information in this document has been carefully reviewed and is believed to be
reliable, ETS-Lindgren does not assume any liability arising out of the application or use of any product
or circuit described herein; nor does it convey any license under its patent rights nor the rights of others.
All trademarks are the property of their respective owners.
© Copyright 1995 - 2022 written permission from ETS-Lindgren Inc. All Rights Reserved. No part of
this document may be copied by any means without written permission from ETS-Lindgren Inc.
Trademarks used in this document: The ETS-Lindgren logo is a registered trademark of
ETS-Lindgren Inc.; Teflon is a registered trademark of E. I. du Pont de Nemours and Company or
its affiliates.
Revision Record
MANUAL, HI-3702 | Part # H-600070 Rev J
Revision Description Date
Initial Release November, 1995
AUpdates May, 1996
BUpdate battery charger June, 1997
CAdd CE label June, 1997
DAdd Appendix A January, 1998
EUpdate battery charger
specifications
August, 1999
FUpdate contact information;
reformat
February, 2006
GUpdate frequency range;
rebrand
February, 2009
HUpdate to battery charger
options; rebrand
February, 2021
JRemove references to obsolete
products
August, 2022

32
TABLE OF CONTENTS
NOTES, CAUTIONS AND WARNINGS 5
SAFETY INFORMATION 6
INTRODUCTION 7
Standard Conguration � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �7
Optional Items� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �7
ETS-Lindgren Product Information Bulletin � � � � � � � � � � � � � � � � � � � � � � � � � � � �8
MAINTENANCE 9
Battery Maintenance � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �9
Annual Calibration � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �9
Maintenance of Fiber Optics � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 10
Replacement and Optional Parts � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 10
Service Procedures � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 10
RANGES & SPECIFICATIONS 11
Ranges � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 11
Specications � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 11
HI-3702 Typical Frequency Response � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 12
OPERATION 13
Computer Controlled Data Logging � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 15
Battery Charging� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 15
Error Codes � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 16
FUNCTIONAL THEORY OF OPERATION 17
APPENDIX A: SERIES H-491198-36 BATTERY CHARGER 18
Introduction � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 18
Charging the Battery � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 18
Charging Indicators� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 18
Specications � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 19
Maintenance Recommendations � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 19
Replacing the Fuse� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 19

4
APPENDIX B: TYPE 1738819 BATTERY CHARGER 21
Introduction � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 21
Charging the Battery � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 21
Charging Indicators� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 21
Specications � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 22
Maintenance Recommendations � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 22
APPENDIX C: EC DECLARATION OF CONFORMITY 23
Hi-3702 Clamp-On Induced Current Meter� � � � � � � � � � � � � � � � � � � � � � � � � � � � � 23
Series H-491198-36 Battery Charger � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 24

54
NOTES, CAUTIONS AND WARNINGS
Note: Denotes helpful information intended to provide tips for better
use of the product.
CAUTION: Denotes a hazard. Failure to follow instructions could
result in minor personal injury and/or property damage. Included
text gives proper procedures.
WARNING: Denotes a hazard. Failure to follow instructions could
result in SEVERE personal injury and/or property damage. Included
text gives proper procedures.
*All notes, cautions, and warnings will be located on the left column area of the page.
See the ETS-Lindgren Product Information BulletinProduct Information Bulletin for safety, regulatory, and other product
marking information

6
SAFETY INFORMATION
See the ETS-Lindgren Product Information Bulletin for safety, regulatory,
and other product marking information.
Warning: This is a Safety Class I product (provided with a protective
earthing ground incorporated in the power cord). The mains plus shall
only be inserted in a socket outlet provided with a protective earth
contact. Any interruption of the protective conductor, inside or outside
the instrument, is likely to make the instrument dangerous. Intentional
interruption is prohibited. DO NOT defeat the earth grounding protection
by using an extension cable, power cable, or autotransformer without a
protective ground conductor.
Caution: Uninsulated voltage within the unit may have sufficient
magnitude to cause electric shock. Therefore, it is dangerous to make any
kind of contact with any parts inside this unit.
Caution: This instrument is shipped with a three-wire power cable, in
accordance with international safety standards. When connected to an
appropriate power line outlet, this cable grounds the instrument cabinet.
Warning: No operator serviceable parts exist inside. Refer servicing to
qualified personnel. To prevent electrical shock, do not remove covers.
Warning: The battery charger incorporates parts, such as a switch and
relay that potentially could produce sparks or arcs.
Warning: For indoor use only, do not expose to rain.

76
INTRODUCTION
The ETS-Lindgren HI-3702 Clamp-On
Induced Current Meter measures
the induced body current of
individuals working in environments
where radio frequency (RF)
electromagnetic fields are present.
The HI-3702 is designed to meet
the requirements of IEEE C95.1-
1991 Standard for Safety Levels with
Respect to Human Exposure to
Radio Frequency Electromagnetic
Fields, 3 kHz to 300 GHz.
IEEE C95.1-1991 defines the acceptable levels of RF-induced body current
for the frequency range of 3 kHz to 100 MHz. The acceptable levels range
from 3 mA for uncontrolled exposures at 3 kHz, to 200 mA for controlled
exposures between 100 kHz and 100 MHz.
The accuracy of the HI-3702 provides a means for determining compliance.
The unit is completely portable and self-contained, and is simple to set up
and easy to operate. The rugged design can be used for measurements in
environments such as:
• Induction heating facilities
• Industrial welding applications
• Broadcast transmitting and antenna locations
Standard Configuration
• HI-3702 Clamp-On Current Sensor
• HI-4416 Digital Readout/Control Unit with fiber optic cable
• Series H-491198-36 Battery Charger/ Series 1737570 Battery Charger
• Carrying Case
Optional Items
• HI-4413USB - USB to Fiber Optic Interface
• HI-4413P Fiber Optic Modem
HI-3702 Clamp On Current Sensor & HI-4416
Digital Readout/Control Unit

8
ETS-Lindgren Product Information Bulletin
See the ETS-Lindgren Product Information Bulletin included with your
shipment for the following:
• Safety, regulatory, and other product marking information
• Steps to receive your shipment
• Steps to return a component for service
• ETS-Lindgren calibration service
• ETS-Lindgren contact information

98
Before performing any
maintenance, follow
the safety information
in the ETS-Lindgren
Product Information
Bulletin included with
your shipment.
Maintenance of the
HI-3702 is limited to
external components
such as any cables
or connectors.
Do not open the HI-3702
housing. Warranty may
be void if the housing
is opened.
If you have any
questions concerning
maintenance, contact
our ETS-Lindgren
Customer Service.
Under normal operating
conditions, recharging
the battery is the only
HI-3702 maintenance
performed by the user.
MAINTENANCE
Take care to keep dirt and moisture from getting inside the housing of the
HI-3702 Clamp-on Induced Current Meter and on the coplanar surfaces of
the ferrite core that are exposed when the clamp-on sensor is open.
Do not use high-pressure sprays, and under no circumstance should the
unit be immersed in water or other liquid; the HI-3702 is not waterproof.
Such actions void the warranty.
Battery Maintenance
Maintaining the HI-3702 requires that the nickel-cadmium (NiCd)
battery be properly charged and the battery condition monitored.
The normal operational life of the battery (approximately 1000
charge/discharge cycles) is such that by the time the battery needs
replacement; the HI-3702 will need recalibration; these tasks are
performed by ETS-Lindgren. For information on calibration services, see
Annual Calibration below.
For the steps to charge the battery, see page 15.
In case of damage to the battery that causes premature failure,
the HI-3702 must be sent to ETS-Lindgren for battery replacement;
replacement in the field is not possible. See Service Procedures on page
10 for information on returning the HI-3702 to ETS-Lindgren for service.
Annual Calibration
See the Product Information Bulletin included with your shipment for
information on ETS-Lindgren calibration services.

10
Before performing
any maintenance,
disconnect the fiber
optic cables from the
unit and turn off power.
Failure to perform
these tasks may result
in damage to either
or both the fiber optic
connectors cables.
Maintenance of Fiber Optics
Fiber optic connectors and cables can be damaged from airborne particles,
humidity and moisture, oils from the human body, and debris from the
connectors they plug into. Always handle connectors and cables with care,
using the guidelines as follows:
• When disconnecting fiber optic cables, apply the included dust caps to the
ends to maintain their integrity.
• Before connecting fiber optic cables, clean the connector tips and also the
in-line connectors.
• Before attaching in line connectors, clean them with moisture-free
compressed air.
Replacement and Optional Parts
The following are the part numbers for ordering replacement or optional parts
for the HI-3702.
Part Description Part Number
HI-3702 Fitted Carrying Case H-491132
HI-4416 Digital Readout/Control Unit HI-4416
Fiber Optic Cable, 2-meter H-491106-02
Battery Chargers H-491198-36; 1737570
HI-4413P Fiber Optic Modem HI-4413P
USB to Fiber Optic Interface HI-4413USB
12V Auto Lighter Power Cord H-22270-1534D
Service Procedures
For the steps to return a system or system component to ETS-Lindgren for
service, see the Product Information Bulletin included with your shipment.

1110
RANGES & SPECIFICATIONS
Ranges
Autorange: 1.00 mA–1.000 A
Range 1: 1.00 mA–10.0 mA
Range 2: 3.1 mA–31.6 mA
Range 3: 10.0 mA–100.0 mA
Range 4: 0.031 A–0.316 A
Range 5: 0.100 A–1.000 A
Specifications
Typical Frequency Response: 9 kHz–70 MHz ±2.0 dB
Linearity: ±0.5 dB
At lower levels, the linearity for Range 1 deviates within
±0.5 dB due to noise. The remaining ranges follow the ideal
curve as shown for Range 2 in Typical Frequency Response
on page 15.
Fiber Optic Connectors: Standard FSMA
Fiber Optic Cable: 200 micron, Graded Index, Multimode, Max Length 1 Km
Readout: HI-4416 Digital Readout/Control Unit
Physical Specifications
HI-3702 Inner Diameter: 105.4 mm (4.15 in)
HI-3702 Outer Diameter: 171.4 mm (6.75 in)
HI-3702 Height: 72.6 mm (2.86 in)
HI-3702 Weight: 1.7 kg ( 3 lb 13 oz)
HI-4416 Digital Readout/
Control Unit:
0.42 kg (14.8 oz)
Cushioned Case: 0.085 kg (3.0 oz)
Fiber Optic Cable: 0.071 kg (2.5 oz)
Battery/Battery Charger
Battery: 3.6 VDC, 1400 mAH rechargeable nickel-cadmium (NiCd)
Battery Charger: 115/230 VAC, approximately one hour
Battery Life: Approximately 5 hours of continuous operation per full
charge.
Environmental
Humidity: 5% to 95% relative humidity, non-condensing
Operating Temperature: 10°C–40°C (50°F–104° F)

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HI-3702 Typical Frequency Response

1312
Before connecting any
components, follow
the safety information
in the ETS-Lindgren
Product Information
Bulletin included with
your shipment.
If you use this
equipment in a
manner not specified
by ETS-Lindgren, the
protection provided by
the equipment may be
impaired.
Do not position the
equipment so that it
is difficult to connect
cables to or disconnect
cables from the back of
the unit.
OPERATION
1. Charge the battery
Cable Connectors
The battery charger requires approximately one hour to charge the battery
to maximum capacity. Under normal operation, a fully-charged battery
should provide five hours of operation. If the battery fails to hold a charge
or if a significant degradation in operational time occurs, you may need to
replace the battery.
2. Connect the fiber optic cables.
Connect the fiber optic cable to the HI-3702 and to the HI-4416 Digital
Readout/Control Unit. Follow the color coding on the fiber optic cable, the
HI-3702, and the HI-4416.
3. Power on the HI-3702.
Turn on the HI-3702. It is equipped with a locking lever on/off switch. Pull
the switch lever out before toggling it to the appropriate position.
4. Power on the HI-4416.
Turn on the HI-4416. See the HI-4416 user manual for more complete
operating information.
5. Select the range.
Use the HI-4416 to select the range that is appropriate for the expected
current levels to be measured. To select auto range, scroll through the
ranges until Range A appears on the screen.
Before taking any
measurements, charge the
battery to maximum capacity.
For the steps to charge the
battery, see page 15.
The nickel-cadmium (NiCd)
battery installed in the HI-
3702 Clamp-on Induced
Current Meter was charged
prior to shipment; however,
NiCd batteries can self-
discharge to nearly zero
capacity after two months.

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When auto range is enabled, the probe will scroll up to the next higher range
when the reading displayed exceeds full scale. The probe will scroll down to the
next lower range when the reading displayed is - 14 dB (20%) of the full scale
reading for the current range. This will put the reading at approximately 2/3 of
full scale of the next lower range. See the following Auto Range Readings Table
and Auto Range Flow Diagram.
Range - 20dB of
full scale
Reading
after scroll
down
-14dB of
full scale;
scroll down
point
Full scale
scroll up
point
Reading
after scroll
up
Full scale
reading
11 mA 7.2 mA 10 mA 10 mA
23.16 mA 20 mA 7.2 mA 31.6 mA 10 mA 31.6 mA
310 mA 72 mA 20 mA 100 mA 31.6 mA 100 mA
431.6 mA 200 mA 72 mA 316 mA 100 mA 316 mA
5100 mA 200 mA 316 mA 1000 mA
6. Select averaging.
Use the HI-4416 to select Instantaneous Readings or One-Second Averaging.
The HI-3702 collects a measurement approximately seven times per second.
When the X-axis is selected, each measurement is sent to the display. When the
Y-axis is selected, the one-second average of the measurements is displayed.
The averaging algorithm stores the seven most recent measurements. Each
time a measurement is taken, the algorithm drops the oldest value, adds in the
new value, and then recalculates the average and sends the new average value
to the display.
7. Attach the clamp-on current sensor.
Place the clamp-on current sensor on the arm or leg of the body under test
and close the buckle. For accurate measurements, verify that nothing interferes
with complete closure of the clamp-on current sensor. Make sure no clothing
is caught between the coplanar surfaces of the ferrite core material or the
aluminum housing.
Auto Range Readings Table
Auto Range Flow Diagram

1514
Never attempt to
recharge a non-
rechargeable battery.
Note:
If the battery has been
through its normal life
span of approximately
1000 charge/discharge
cycles, return the HI-
3702 to ETS-Lindgren
for battery replacement
and recalibration. For
more information, see
Battery Maintenance
on page 9.
Displayed readings that are less than 10% of the full scale reading for the selected
range are not valid. When Range 1 or Autorange is selected and there is no
current passing through the current meter, a noise floor reading will display. This
is a normal operating condition.
Computer Controlled Data Logging
Software is available for the personal computer that simulates the HI-4416. For
information on using the HI-4416 for data logging, see the HI-4416 manual.
The HI-3702 is
connected for data
logging as shown.
To connect the HI-3702 to a PC serial port, use the optional model HI-4413P and
RS232 cable assembly (PN H-2239615). For connection to a PC USB port, use the
optional model HI-4413USB (cable included).
Battery Charging
1. Turn off the HI-3702.
2. Connect the battery charger/wall transformer to an AC outlet.
3. Plug the charger jack completely into the CHARGE connector on the clamp
on current sensor.
Allow approximately one hour for a full charge cycle. When charging is
complete, the battery charger automatically goes into a trickle charge. It
will remain in trickle charge mode until disconnected from the HI-3702.
4. When the charge cycle is complete, remove the charger jack from the
CHARGE connector on the clamp-on current sensor.
5. Unplug the battery charger from the AC outlet.
6. Use the HI-4416 to verify that the battery is charged to approximately 3.8 VDC.
See the appendices for your model for complete information on the battery
charger.

16
Error Codes
If an error occurs, the probe will respond with one of the following strings.
These strings begin with a colon and end with a carriage return.
Error String
E01
Communication error (for example, overflow)
E02
Buffer full error; too many characters contained between the start
character and carriage return sequence
E03
Received command is invalid
E04
Received parameter is invalid
E05
Hardware error (for example, EEPROM failure)
E06
Parity error
E9
Received command is invalid

1716
FUNCTIONAL THEORY OF OPERATION
Following is a functional theory of operation for the HI-3702 Clamp-on Induced
Current Meter. The objective is to enhance user understanding of the theory
behind the design to aid with the operation and maintenance of the HI-3702.
Theory of Operation
The HI-3702 is designed to measure RF induced current flowing through the
ankles or arms of the body under test, even while walking or climbing. The fiber
optically coupled readout/control unit does not perturb the measured RF field or
the current distributions.
The sensor is a ferrite split core current transformer. The signal generated by the
sensor is amplified by 10 dB to 50 dB depending on the range that is selected.
There is 20 dB of linearity for each range. This signal is applied to a True RMS
Thermal RMS to DC Converter. The DC voltage output of the True RMS Thermal
RMS to DC Converter is applied to a 12 bit A/D converter. This digital representation
of the DC voltage is read by the microprocessor, converted to a number that is
representative of current being sensed, and transmitted through the fiber optic
interface to the HI-4416 Digital Readout/Control Unit.

18
Note:
The HI-3702 Clamp-
on Induced Current
Meter contains a
nickel-cadmium (NiCd)
battery, and uses
the Series H-491198-36
Battery Charger.
Before operating the
Series H-491198-36
Battery Charger, see
Safety Information on
page 6.
Never attempt to
recharge a non-
rechargeable battery.
APPENDIX A: SERIES H-491198-36 BATTERY
CHARGER
Introduction
The Series H-491198-36 Battery
Charger is a dual power source
battery charger. It charges 3.6
Volt 1400 mAH NiCd batteries and
is powered by 120-240 VAC line
power or 12.5 VDC. The H-491198-36
charger uses a -(dV)/(dT) negative
delta V technique to determine
when the battery is fully charged,
which is typically one hour. With
this technique, the charge state of
the battery has no effect other than
shortening the charge time.
Housed in a rugged enclosure, power enters the battery charger through a
power entry module, which contains the fuses, or an optional cigarette lighter
plug adapter. The front face of the battery charger displays LEDs that provide
the operating status. The battery charger connects to the device being charged
through a short cord terminated with a power jack.
An integrated circuit within the battery charger monitors the battery voltage and
controls the charging functions according to the charge state of the battery.
Charging the Battery
For the steps to charge a battery, see page 15.
Charging Indicators
The following LEDs are located on the front of the battery charger:
• POWER ON (green)—Indicates the battery charger is connected to the AC
power source.
• NO BATTERY (amber)—Indicates the battery charger does not detect
a battery.
• PENDING (amber)—Indicates the battery charger detects a battery.
Before fast charging can begin, the battery voltage must fall within
predetermined acceptable limits. A pulse-trickle charge is provided to bring
a depleted battery to a valid charge prior to fast charge.
• CHARGING (amber)—Indicates the voltage pre-qualification condition has
been met, and fast charge has started.
• COMPLETE (green)—Indicates a fast charging peak voltage is detected. The
Field Probe can remain connected to the battery charger indefinitely while
in this maintenance mode.

1918
Disconnect the battery
charger from power
before replacing a fuse.
Specifications
Power
Main: IEC filtered AC power input module ; 110-240 VAC, 500 mA
max, 50-100 Hz
Alternate: Automobile cigarette lighter to 2 mm power plug adapter
cord, 12.5 Vdc, 100 mA
Fuses: 250 Volt, 1.0 Amp, Type T (5 mm x 20 mm)
Output
Open Circuit Voltage: 15 Vdc
Fast Charge Pending Current: 60 mA
Fast Charge Current: 1400 mA
Pulsed Trickle Charge Current: 50 mA
Output Voltage (During Fast
Charge):
3–6 Vdc
Battery
NiCd Battery: 3.6 Volt 3 Cell NiCd Battery, 1400 mAH (rapid charge cells, 1.2
Volts/cell)
ETS-Lindgren Part #491038
Environmental
Operating Temperature: 10°C–40°C (50°F–104°F)
Humidity: 5% to 95% relative humidity, non-condensing
Maintenance Recommendations
• Operate the battery charger with care.
• There are no user serviceable parts inside the battery charger. Opening the
battery charger housing may void your warranty.
Replacing the Fuse
If the battery charger fails to operate, check for a blown fuse inside the power
entry module. A blown fuse must be replaced with the same value and type of
fuse, or an unsafe condition may result. Use only 250 Volt, 1.0 Amp, Type T (5 mm
x 20 mm) fuses.
To replace a fuse:
1. Two fuses are located in the fuse drawer in the power input module. Use a
screwdriver to open the drawer.
2. The fuse towards the outside of the drawer is the spare. Remove the spare
fuse from the module.

20
3. Replace the blown fuse with the spare fuse.
4. Slide the fuse drawer back into the module. Make sure that the drawer snaps
securely into its locked position.