Atec EHP-50D User Manual

ELECTRIC AND MAGNETIC FIELD ANALYZER

EHP-50D

C FIELD ANALYZER

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

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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.

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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.

Application focus: simultaneous three-axis measurement

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:

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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"

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