Selective and broadband
low frequency field
analysis
State of the art technology with simultaneous
three-axis acquisition
Low frequency electric and magnetic field analysis
up to 100 kHz
Isotropic measurement with total dynamic range
up to 150dB
Small size and optical fiber connection for spot
measurements
Built-in FFT spectrum analysis
Wideband mode
Built-in Li-ion rechargeable battery
with long operating life
Interface to NBM-550 field meter and PC
Stand-alone operating mode with internal data logger
www.narda-sts.com
EHP-50D
EHP-50D 04-11 1 / 12Subject to change without notice
LOW FREQUENCY ELECTROMAGNETIC FIELDS
Electrosmog is a term commonly used to describe any
phenomenon or problem associated with artificially generated
electric or magnetic fields. A range of electric or electronic
devices may cause an environmental risk and - under certain
conditions - generate potentially hazardous electric or magnetic
fields. However, special attention is focused on low frequency
fields such as those generated by power transmission lines,
railroads, and high current equipment in general (large electric
motors, industrial-scale manufacturing plant, power generators,
etc.). These low frequency fields are basically characterised by
high electric and magnetic field component values in the near
field region, although these values decrease rapidly over
distance. The risk of exposure to potentially harmful low
frequency fields may be present elsewhere (e.g. offices near
large machinery, homes close to a high voltage power line, etc.).
As several studies around the world have confirmed the potential
risks from irradiation with strong low frequency electric or
magnetic fields, electrosmog and its possible consequences are
under close consideration by IEC, CENELEC, ICNIRP and many
other national organisations. New standards are being prepared
and all reasonable protection measures are being taken to
preserve the health of workers and citizens all over the world.
EHP-50D 04-11 2 / 12Subject to change without notice
EHP-50D
Electric and Magnetic Isotropic Field Analyzer
The EHP-50D is not simply an upgrade of the EHP-50C, but
represents a real leap in technology made possible by the
availability of even more sophisticated components that can
provide high level performance while keeping the physical
dimensions and intrinsic noise level small.
The EHP-50D gives users the choice of three measurement
modes: Wideband, which measures the contribution of all the
frequency components in the selected frequency span; Highest,
which measures only the highest level found within the span; and
Spectrum, which includes marker functions. The spectrum analysis
feature means that the EHP-50D can be used to measure only the
field contribution from the selected source, such as a high voltage
line, excluding other nearby interfering frequencies. Everything is
contained in the small (approx. 1 dm
three magnetic coils and three plate capacitors orthogonally
positioned for sensing the fields; a multi-channel analog to digital
converter followed by a powerful DSP (digital signal processor) for
analyzing the signal; the CPU module that controls all the functions;
2
PROM that stores the calibration data and the frequency and
an E
level calibration tables; an optical interface to allow easy connection
to external displays via optical fiber link; a high capacity data logger
for stand alone continuous acquisition; and the control panel with
the connections and the ON/OFF switch.
The EHP product family is a unique solution providing both E and
H field measurement, including spectrum analysis, in a single,
small size casing. Thanks to its multi-channel A/D converter, the
EHP-50D additionally provides simultaneous three-axis
acquisition for unsurpassed performance even in the most
complex applications. Specialists in the low frequency field who
were mainly performing measurements to assess the exposure of
the public to the relatively steady fields emitted by power lines
are now facing new challenges to provide answers regarding field
exposure in the workplace. According to various standards and
regulations as well as to the European directive, which will be
effective from April 2012, work environments must be assessed
in order to ensure that the maximum permitted field levels
recommended in the ICNIRP guidelines are never exceeded. The
industrial environment not only encompasses devices generating
relatively steady fields, but also includes welding machines and
other devices generating very complex or pulsed fields.
Simultaneous three-axis measurement is therefore mandatory for
these applications, which consulting companies, industrial health
and safety departments, and workplace health and safety
agencies will be asked to perform more and more in future.
3
), cubic EHP-50D housing:
EHP-50D 04-11 3 / 12Subject to change without notice
EHP-50D Operation
The EHP-50D adopts the same extremely flexible operating
concept found in preceding models, such as “Stand Alone” mode,
remote control by PC via an optical connection, and remote E
and H field sensor for portable field meter.
The EHP-50D as well as its different operating modes therefore
appears to be the same as the EHP-50C but it has a completely
new “heart” beating within it to give the highest level of
performance even in the most complex situations.
The EHP-50D was designed to provide all the performance,
capacity and functions needed, and is shown as the best tool for
measuring low frequency electric and magnetic fields and
displaying, recording and analyzing their values on the NBM-550
field meter or a PC screen. The PC program allows for remote
control by optical fiber as well as for setting the probe and
downloading measurement results acquired in "Stand Alone"
mode or stored in the NBM-550 memory. The EHP-50D provides
an advanced solution for field measurements in the 5 Hz to 100
kHz range, with an unsurpassed total dynamic range of up to 150
dB and a built-in spectrum analyzer function.
EHP-50D Operating Modes
- Stand-Alone Operating Mode
- NBM-550 Display Operation
- EHP-TS Remote Controlled Operation
STAND-ALONE OPERATING MODE
Continuous acquisition with internal data logger for
up to 24 hours
When long-term monitoring is essential, such as when measuring
magnetic fields close to high, medium and low voltage
transformers, close to power lines or to machinery, air
conditioning systems, large home appliances, and so on, the
EHP-50D can be used in stand-alone mode
without needing to be connected to a PC or a NBM-550 meter.
Once the measurement parameters have been programmed
using the PC software (supplied), the EHP-50D analyzer can
start acquisition and storage of the data in stand-alone mode for
a period of 24 hours at a sampling rate of once every 30 or 60
seconds. The EHP-50D will stop automatically after 24 hours.
The data can then be downloaded to the PC. The PC software
enables you to select measurement (electric or magnetic field),
full scale, mode (Highest or Wideband), frequency span, and
sampling interval (one minute or 30 seconds).
EHP-TS control software includes the
application "EHP50 - Stand Alone mode"
EHP-50D 04-11 4 / 12Subject to change without notice
NBM-550 DISPLAY OPERATION
Handheld display unit for field measurements
The EHP-50D can also be easily operated through the
Broadband Field Meter NBM-550. In order not to influence the
field to be measured, communication between the EHP-50D
Analyzer and the NBM Unit is through a rugged optical fiber
cable. The NBM-550 supports the following settings and
measurement modes:
- Electric or magnetic field selection (1 kV/m; 100 kV/m;
100 µT;10 mT)
- Span selection (100 Hz to 100 kHz)
- Wideband or highest peak modes
- Spectrum mode
- Monitor mode (Actual; Max; Avg; Min)
- XYZ mode (wideband or highest peak)
Additional features include:
- Measurement setups
- Normalized spectrum in % relative to a standard (e.g.
ICNIRP)
- Alarm with adjustable thresholds for electric and
magnetic field
- Averaging (4 to 32 samples) and Maximum Hold
- Unit selector for Tesla / Gauss
- Full resolution spectrum marker
- Data storage on NBM-550 including spectrum data
- Timer Logging
- Post-averaging for logged data on PC (RMS, Mean,
Median)
- Powerful PC software NBM-TS for evaluation and
documentation
The NBM-TS application software, which is included with the
The NBM-TS application software, which is included with the
Narda Broadband Field Meter NBM-550, provides functions for
Narda Broadband Field Meter NBM-550, provides functions for
transferring the results that have been stored in the meter
transferring the results that have been stored in the meter
memory to a personal computer. It also includes data evaluation
memory to a personal computer. It also includes data evaluation
and measurement database management functions.
and measurement database management functions.
All the numerical value and spectrum analysis results stored in
All the numerical value and spectrum analysis results stored in
the meter can therefore be transferred to the user’s PC for further
the meter can therefore be transferred to the user’s PC for further
evaluation and analysis, stored in the database, and used to
evaluation and analysis, stored in the database, and used to
prepare detailed reports.
prepare detailed reports.
Highest peak as % of
standard
EHP-50D 04-11 6 / 12Subject to change without notice
EHP-TS REMOTE CONTROLLED OPERATION
Displaying electric and magnetic field values in a
spectrum analysis graph
The EHP-TS control software allows the user to control Narda
analyzers such as the EHP-50C/D and EHP-200/A from a PC.
The optical cable coming from the analyzer (max. length: 40 m) is
easily connected to the PC using the optical to USB converter
(USB-OC) provided. If a longer distance is required, the optional
8053-OC optical to RS232 converter can be used for optical fiber
lengths of up to 80m.
A user-friendly graphical interface includes the commands for
setting all the parameters. To make them easier to understand,
the controls are grouped on five selectable tabs. The spectrum
measurement is continuously displayed and updated. Both
electric and magnetic field spectrum measurements can be
displayed on the same graph.
The Sweep, Mode, Limit and Appearance tabs are used to set all
the measurement and display parameters, while the Data tab
with the Marker controls shows numerical results like the field
strength and frequency at the marker and highest peak positions.
A wideband measurement is also displayed, which includes all
the field contributions within the spectrum shown. Several
different units, including percentage of limit value, can be
selected for displaying the measurement results, which can be
saved along with user comments either as bitmap or as text files
so that they can easily be imported into other software
applications such as spreadsheets or word processors.
Following the so-called precautionary principle, many countries
have adopted their own reference limits. Besides having the
ICNIRP limits already included, EHP-TS also allows the user to
create and save customized limits that may reflect local
regulations as well as user-specific requirements. All the values
of the selected limit are always included for reference in any
.bmp or .txt file saved. The availability of lightweight devices
equipped with the Windows
and similar devices, makes EHP-TS software the ideal solution
for performing accurate in-field spectrum analysis with the
minimum of effort using lightweight equipment.
TM
operating system, such as UMPC
(1)
The limit value can be shown at the Marker frequency.
The Data tab shows numerical results and includes
Marker controls and Save buttons.
The spectrum can be shown as a percentage of the selected
limit. The Mode tab allows selection of different acquisition
modes as well as the range, units and linear or logarithmic
frequency scale.
Both electric and magnetic fields can be displayed
on the same graph.
(1) Earlier versions of the EHP50 analyzer (EHP-50, EHP-50A, EHP-50B) must be hardware updated to EHP-50C to operate in conjunction with EHP-TS control software.
For information contact your Narda distributor.
EHP-50D 04-11 7 / 12Subject to change without notice
TECHNICAL SPECIFICATIONS
EHP-50D
FUNCTIONAL SPECIFICATIONS
Frequency Range 5 Hz ÷ 100 kHz
Measurement Ranges
Overload200 kV/m 20 mT
Dynamic range 106 dB 110 dB
Resolution
Displayed Average Noise Level
Isotropic result
Single axis
Flatness (@ 100V/m and 2µΤ)
(5 Hz ÷ 40 Hz)
(40 Hz ÷ 100 kHz)
Typical 3D anisotropy
Linearity
SPAN
Start frequency 1.2 % of the SPAN
Stop frequency
Rejection to E fields --- > 20 dB
Rejection to H fields > 20 dB ---
Spectrum analysis method
Acquisition method
Internal data logger
Internal memory
(1) Unless otherwise indicated, specifications are referred to an ambient operating temperature of 23°C and relative humidity of 50%
(2) For each individual axis. Ranges to be selected manually
(3) For the lower measurement range
(4) DANL is frequency and SPAN dependent. The specified best performance is referred to f ≥ 50Hz and SPAN ≤ 1kHz
(5) Typical value @ 50Hz, see application note "BG_0509_ELF_measurements_uncertainty” for details
(6) Referred to 100 V/m and 1 µT @ 50 Hz
(7) Measurement results acquired in stand alone mode can be transferred to PC only
(1)
(2)
(3)
(4)
(5)
(6)
(7)
Electric Field Magnetic Field
5 mV/m ÷ 1 kV/m
500 mV/m ÷ 100 kV/m
(total measurement range: 146 dB)
1 mV/m with NBM-550
0.1 mV/m with EHP-TS software
1 mV/m in Stand Alone mode
Probe EF 0391, E-Field, for NBM, 100kHz-3GHz
Probe EF 1891, E-Field, for NBM, 3MHz-18GHz
Probe EF 5091, E-Field, for NBM, 300MHz-50GHz, Thermo.
Probe EF 6091, E-Field, for NBM, 100MHz-60GHz
Probe HF 3061, H-Field, for NBM, 300kHz-30MHz
Probe HF 0191, H-Field, for NBM, 27MHz-1GHz
Probe EA 5091, FCC Shaped, for NBM, 300kHz-50GHz, E-Field
Probe EB 5091, IEEE Shaped, for NBM, 3MHz-50GHz, E-Field
Probe EC 5091, SC 6 Shaped, for NBM, 300kHz-50GHz, E-Field
Probe ED 5091, ICNIRP Shaped, for NBM, 300kHz-50GHz, E-Field
Probe EF 5092, E-Field, Hi Power, for NBM, 300MHz-50GHz, Thermo.
Probe EF 0392, E-Field, Hi Power, for NBM, 100kHz-3GHz
Probe EF 0691, E-Field, for NBM, 100kHz-6GHz
ACCESSORIES
Test-Generator 27 MHz
Tripod, Non-Conductive, 1.65m, with Carrying Bag 2244/90.31
Tripod Extension, 0.50m, Non-Conductive (for 2244/90.31) 2244/90.45
Handle, Non-Conductive, 0.42m 2250/92.02
Carrying Strap, Hard Case, for SRM/NBM-500 3001/90.04
Cable, Coaxial Multi-pin/ BNC, for NBM-550, Ext. Trigger, 2m 2400/90.04
Cable, FO Duplex (1000 µm) RP-02, 2 m 2260/91.02
Cable, FO Duplex (1000 µm) RP-02, 20 m 2260/91.03
Cable, FO Duplex, F-SMA to RP-02, 0.3 m 2260/91.01
O/E Converter RS232, RP-02/DB9 2260/90.06
O/E Converter USB, RP-02/USB 2260/90.07
Cable, Adapter USB 2.0 - RS232, 0.8 m 2260/90.53
Protective Pouch for NBM-550 2401/90.01
Protective Pouch for NBM Probe, up to a diameter of 104 mm (all NBM probes, not 2402/05) 2402/90.01
® Names and Logo are registered trademarks of Narda Safety Test Solutions GmbH and L3 Communications Holdings, Inc. – Trade names are trademarks of the owners.
Narda Safety Test Solutions
435 Moreland Road
Hauppauge, NY 11788, USA
Phone: +1 631 231-1700
Fax: +1 631 231-1711
E-Mail: NardaSTS@L-3COM.com
www.narda-sts.us