Atec EHP-50C User Manual

Electric and Magnetic Field Measurement

EHP-50C Electric Field and
Magnetic Flux Density Analyzer

Electric Field and Magnetic Flux Density Analysis ♦
from 5 Hz to 100 kHz

♦

Isotropic Measurements with a Dynamic Range
of 140 dB

♦

Small Size and Optical Fiber Connection for
Accurate, Repeatable Measurements

♦

Built-in FFT Spectrum Analysis
Three (Narrowband, Broadband and Marker) ♦

Detection Modes

♦

Internal Memory for Stand Alone Measurements
Interfaces to PC and Pocket PC ♦

Measurements of ELF/VLF (Extremely Low Frequency and Very Low Frequency)
fields, in an accurate and repeatable manner, have long been a difficult proposition.
Interference caused by the proximity of the surveyor has made E-field measurements
especially difficult, and most devices have offered only single axis sensors rather than
isotropic arrays that only served to further reduce repeatability. With new standards
and recommendations (like IEEE C95.6) being introduced and the increase of implant­ed medical devices, there is an increased need to know what the field levels are in our
workplaces and/or around the products we manufacture no matter what their direc­tion or orientation.

The Narda EHP-50C is a new and innovative system that has been designed to offer the
highest performance, capabilities and functions, for measurements of low frequency
electric and magnetic fields. The EHP-50C performs E and β field measurements in the
5 Hz to 100 kHz range with an unsurpassed dynamic range of > 140 dB and built-in
spectrum analyzer function. The EHP-50C, along with a display device (PC or Pocket
PC), allows the user to select among 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, with marker functions.

Narrowband spectrum analysis capability of the EHP-50C makes it possible to measure
only the contribution from the selected source – e.g. a high voltage line – excluding
other nearby additional frequencies.

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narda Safety Test Solutions an communications company USA • Germany • Italy

USA TEL: [phone] • FAX: [phone] • E-MAIL: [e-mail] • www.narda-sts.us

Electric and Magnetic Field Measurement

EHP-50C Electric Field and Magnetic Flux Density Measurement

The EHP-50C’s small cubic housing (approx. 4 in.) accom­modates everything: three magnetic loops and three plate
capacitors orthogonally positioned for sensing fields from any
direction. Encased inside the housing is also an A to D con­verter followed by a powerful DSP (Digital Signal Processor)
that performs signal analysis; and the CPU module that con­trols all the functions; an EEPROM, that stores the calibration
data; an optical interface to allow easy connection to external
displays via optical fiber link; a high capacity data logger for
stand alone continuous acquisition; the control panel with
the connections and the ON/OFF switch.

The innovative sensor design, along with the supplied soft­ware allows the user to setup measurement parameters
beforehand on a PC. During or after a measurement, the soft­ware allows displaying, recording and analyzing their values
on a PC.

OPERATION WITH POCKET PC

To further improve the flexibility and the portability of the
solution provided, the EHP-50C also has dedicated software
running on specifically selected Pocket PC’s (HP iPAQ Model
hx2190 or HP equivalent). Data is received from the EHP-50C
through the optical cable and can be easily displayed, ana­lyzed and stored.

The Pocket PC software features digital and analogue reading,
span, range and E or β settings, Marker Peak and Delta Peak. It
is delivered on a standard 32 MB Secure Digital memory card
that can also be used to save the spectra measurements as
well as the corresponding numeric values.

STANDALONE CONTINUOUS ACQUISITION WITH
INTERNAL DATA LOGGER FOR 24 HOURS

If a long monitoring campaign is a must – e.g. when moni­toring magnetic fields that might cause interference with
implanted medical devices or next to high, medium and low
voltage transformers; measuring close to power lines or to
machinery, air conditioning systems, large home appliances,
etc. the EHP-50C can be used in stand-alone mode without
needing a PC, or a Pocket PC connected to it. Once the mea­surement parameters have been programmed by means of
the PC software (supplied), the EHP-50C analyzer can start its
acquisition by storing the data over 24 hours in stand-alone
mode with a sampling rate of 30 or 60 seconds. After 24 hours
the EHP-50C will stop automatically. The data can then be
downloaded to the PC. The PC software allows the user to
select the measurement field (electric or magnetic), the full
scale, the mode (Highest or Wideband), the frequency span
and the sampling interval (one minute or 30 seconds).

EHP-50C with Pocket PC

narda Safety Test Solutions an communications company USA • Germany • Italy

USA TEL: [phone] • FAX: [phone] • E-MAIL: [e-mail] • www.narda-sts.us

33

Electric and Magnetic Field Measurement

EHP-50C Electric Field and Magnetic Flux Density Measurement

PC Software

The supplied software is compatible with WindowsTM and
allows fast analysis of detected fields in real-time or read­ings previously stored by the EHP-50C. The EHP-50C is
supplied standard with a 2m fiber optic cable and a fiber
optic to USB adapter.

1

2

6

DESCRIPTION:

1 – EHP50 software release and firmware of connected analyzer.

2 – Displays frequency while scanning

3 – EHP-50C battery status

4 – Scan activation for each axis (default setting: all axis activated)

5 – Control panel

6 – Spectrum analysis display

The Control Panel allows you to select the Sweep Span and
to Zoom into that span, evaluate Data with automatic peak
detection and marker display – and to save plots as graph­ics or text, Mode selects either E or H fields, instantaneous
or “Maximum Hold”, Limit allows you to set and save limits,
Aspect allows setting of trace colors and label text.

3

4

5

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narda Safety Test Solutions an communications company USA • Germany • Italy

USA TEL: [phone] • FAX: [phone] • E-MAIL: [e-mail] • www.narda-sts.us

Electric and Magnetic Field Measurement

EHP-50C Electric Field and Magnetic Flux Density Measurement

Specifi cations

EHP-50C E and β Field Analyzer

FUNCTIONAL SPECIFICATIONS Electric Field Magnetic Field

Frequency range 5 Hz to 100 kHz

Measuring Ranges 1 kV/m to 100 kV/m 0.1 mT to 10 mT

Overload 200 kV/m @ 60 Hz 20 mT @ 60 Hz

Resolution 0.1 V/m 10 nT

Sensitivity 0.01 V/m 1 nT

Absolute Error ±0.5 dB @ 60 Hz and 1 kV/m ±0.5 dB @ 60 Hz and 0.1 mT

Flatness (40 Hz – 10 kHz) ±0.5 dB ±0.5 dB

Isotropy ±1 dB

Linearity @ 60 Hz ±0.2 dB (1 V/m to 100 kV/m) ±0.2 dB (200 nT to 10 mT)

SPAN 100 Hz, 200 Hz, 500 Hz, 1 kHz, 2 kHz, 10 kHz, 100 kHz

Starting Frequency 1.2 % of the SPAN

Stop Frequency Equal to the SPAN

E-Field Rejection — > 20 dB

H-Field Rejection > 20 dB —

FFT Real Time FFT Analysis

Internal Data Logger 1 measurement every 30 or 60 seconds

Internal memory 1440 data with 1 minute storing, 2880 data with 30 second storing.

GENERAL SPECIFICATIONS

Calibration Internal EEPROM

Temperature Error (referred to 23°C) ±0.05 dB/°C between -10 and +23°C @ 40% RH

Humidity Error (referred to 40%) ±0.05 dB between 20% and 50% @ +23°C

Internal Battery Rechargeable NiMH batteries (5 x 1.2 V)

Operating Time > 10 hours in normal mode

24 hours with internal data logger (SPAN > 200 Hz) in stand alone mode

Recharging Time < 4 hours

External DC supply 10 / 15 V, 200 mA

Optical Fiber Link and operating Distance Up to 80 meters

Firmware Update Via USB port

Operational and Storage Temperature -10°C / 50°C – Storage -20°C / 70°C

Size and Weight 92 x 92 x 109 mm – 25 g

Tripod Support Threaded insert π

ORDERING INFORMATION

Part Number EHP-50C

Accessories Supplied 0.5m Tripod, Optical Shorting Loop, EHP Software,

The data can only be transferred to a PC

±0.01 dB/°C between +23 and +50°C @ 40% RH

±0.05 dB between 50% and 80% @ +23°C

> 150 hours in low power mode

Operating Manual and Calibration Certificate

narda Safety Test Solutions an communications company USA • Germany • Italy

USA TEL: [phone] • FAX: [phone] • E-MAIL: [e-mail] • www.narda-sts.us

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