NARDA 8718B User manual

USER'S GUIDE
Model 8718B
Electromagnetic
Radiation
Survey Meter
P/N 42983600 RevB
narda
SafetyTest Solutions
an communications company
L
3

1Chapter 1 Introduction
1Introduction
About the Model 8718B
Your Model 8718B is a hand-held, battery-powered
meter designed to simplify the measurement of
electromagnetic fields. It can be used with any
Narda 8700 Series probe. The 8718B is an
upgraded version of the original Model 8718.
Although there are many enhancements, the
8718B is most easily distinguished from its
predecessor by the quick-release style probe
connector.
The meter enables you to perform both simple
measurements and more demanding ones that
require averaging and/or data logging. It can be
mounted on a tripod and used with an optional
fiber optic link for enhanced accuracy in certain
applications.
Getting Started with the Model 8718B
It is important to become familiar with the Model 8718B before
you use it. Chapter 2 explains the basic meter hardware.
Chapters 3 and 4 cover probe selection and basic operation.
The menu system, which is the gateway to all the meter’s
advanced features, is the subject of Chapter 5.
It is strongly recommended that, as a minimum, you read
Chapters 2-4, and preferably Chapter 5, thoroughly before you
attempt to use the Model 8718B. The advanced features in
Chapters 6 though 17 can then be referred to as required.
Chapter 18 covers the use of the User's Software.
Return the Owner
Registration Card for
updates and your
copy of the
Applications Booklet.
Note

2Operating the Meter
User’s Guide Updates
This User’s Guide was thoroughly reviewed for accuracy prior to
publication. Corrections to this guide necessitated by errors or
omissions or by minor revisions to the meter firmware will be
covered in the README file enclosed with the User's Software.
The README file is available at any time from the HELP menu
within the User's Software.
Equipment Supplied
Your Model 8718B is supplied with:
•Meter
•Battery Charger/Power Supply
•Power Cord (230 volt chargers only)
•Storage Case
•Probe Extension Cable Model 8744-04
•Electric Field Attenuator Model 8713B
•User's Software (CD-ROM)
•Computer Cable
•User’s Guide
Using this Guide with a Model 8718
The Model 8718 can be upgraded to take advantage of most, but
not all, of the improvements incorporated into the Model 8718B.
The upgrade includes some minor hardware changes and the
installation of the Version 3.0 firmware that is described in this
guide. There are only a few differences in the operation of a
Model 8718 upgraded with Version 3.0 firmware versus the new
8718B. Those differences are noted in this guide.

3Chapter 2 Understanding Your Model 8718B
2Understanding Your Model 8718B
General Description
It is important to be familiar with the Model 8718B before
you use it. This section includes descriptive data keyed to
highlighted illustrations to help you locate the various features
of the meter. The descriptions not only identify the features but
tell you how they are used.
Battery Charger and Power Cord
The battery charger and power cord are used to recharge the
battery within the Model 8718B.
To recharge the meter, first connect the cable of
the battery charger to the larger jack on the left
side of the meter. Make sure the plug is fully
inserted into the jack. Connect the power cord to
the wall outlet.
The battery will be fully charged in about 8 hours.
The indicator light on the charger illuminates
during charging. A full charge will give you about
20 hours of operation (approximately 6.5 hours if
back lighting is used).
The charger can also be used to power the
Model 8718B when it is to be operated for periods
beyond the capacity of the battery.
NiCad batteries
should be fully dis-
charged (<20% indi-
cation) before
recharging. Charge
for a minimum of 8
hours. See Checking
Battery Status in
Chapter 12.
Note

4Operating the Meter
Probe Connection
To make measurements, you must use your
Model 8718B with a compatible probe. Connect
the cable of the probe to the probe connector
located at the top of the unit.
If you use a fiber optic link, the probe connects to a
fiber optic transmitter. A fiber optic cable connects
the transmitter to the rectangular fiber optic jack on
the left side of the meter.
Audio Alarm
Your Model 8718B is equipped with an audible
alarm that emits sound through a tiny hole on the
bottom of the meter. The alarm sounds whenever
the field strength exceeds the measurement range
of the probe (over ranges).
You can also set the meter to sound its alarm at a
specific level and/or turn on a variable-tone mode.
Probe Test Sources
Your Model 8718B is equipped with two RF
sources for testing your probes. The Test Source
key will turn these sources on. They will stay on for
approximately 20 seconds.
A microwave (waveguide) window on the right side
of the probe is used for testing high frequency
probes.
A contact on the right side of the meter is used for
testing low frequency probes. Most probes have
three test points on the head of the probe.

5Chapter 2 Understanding Your Model 8718B
Strap and Tripod Mount
A strap is provided on the underside of the Model
8718B. It has a hook and loop closure to permit
easy adjustment, around your hand.
Behind the strap is a threaded connector used to
secure the meter to a tripod. Loosen the strap to
access this connector.
Operation With a Computer
To update probe calibration information or retrieve
stored measurements, you must connect your
Model 8718B to a personal computer and use the
User's Software provided by Narda.
See Chapter 18, User's Software.
Operation With a Recorder
To obtain a continuous record of measurement
over an extended period of time, you can connect a
data recorder to the smaller jack located on the left
side of the meter.
See Chapter 17, Operation with a Data Recorder.

6Operating the Meter
Keypad
The Model 8718B has four groups of keys distinguished by their
color.
Function keys (green)
Numeric keys (yellow)
Special Function keys (white)
Power keys (blue, green)
Power Keys
Two power keys are used to turn the Model
8718B On and Off.
Function Keys
Use the four function keys
(F1-F4) to select the options displayed on
the bottom line of the display screen
directly above the F1, F2, F3, and F4
markings. In a few cases the options will be
spelled out on the display.
The keys on the
8718B must be firmly
depressed to per-
form their function
and give a tactile
feedback when prop-
erly depressed.
Note

7Chapter 2 Understanding Your Model 8718B
Numeric Keypad
Use the numeric keypad to enter number data into the Model
8718B. You also use the numeric keypad to select a numbered
option listed on the display screen.
Special Function Keys
Six special function keys enable you to perform specific
functions.
Esc Returns you to the previous menu. In a few
cases you must enter a selection rather than
use the Esc key.
Auto Enables you to automatically zero the meter
Zero and probe.
Help Displays a help screen that explains your options.
Test Turns on the built-in low frequency and high
Source frequency probe test sources for approximately
20 seconds.
Range Locks in a specific measurement range for the
bar graph. The digital display is not affected. The
meter automatically displays a digital value over
the probe’s entire measurement range. See Bar
Graph Ranges on page 23.
Enter Stores data you entered with the numeric
keypad. Confirms an option you selected from
a menu screen.

8Operating the Meter

9Chapter 3 Probe Selection
Introduction
The 8700 series RF measurement system offers a very broad
selection of probes. The factors that you should consider in
selecting the probe, or probes, best suited for your task are
described in this section.
3Probe Selection
The probe frequency range should include the frequencies of all
the emitters to be surveyed at one time.
The measurement range of the probe should be adequate for
the field levels that you anticipate, i.e., do you expect strong
fields or weak fields? Probes give more accurate and more
stable readings when they are not used at the extreme low end
of their sensitivity range. Therefore, if you anticipate measuring
very weak fields, select a probe with a lower power full-scale
measurement range to get greater sensitivity. In contrast, higher
power probes give additional safety margins, especially at
microwave frequencies where field strength can change rapidly
with a small change in distance to the source. Select a probe
with a higher power full-scale measurement range if you
anticipate measuring high level fields.
Most standards recommend that you measure both electric (E)
and magnetic (H) fields below 300 MHz (due to the possibility
that measurements may be made in the near field). Since most
experts agree that the electric field poses a greater danger at
lower frequencies due to induced and contact currents that can
occur, the electric field is normally measured first. Higher
frequency measurements are normally made of only the electric
field since measurements will generally be made in the far field.
FREQUENCY
RANGE
POWER
DENSITY
OR FIELD
STRENGTH
ELECTRIC FIELD
VERSUS
MAGNETIC
FIELD
Key Factors in Selecting a Probe

10 Operating the Meter
Flat response probes are the most common. Narda’s patented
shaped frequency response probes read out in Percent of
Standard and are particularly useful in complex, multi-signal
environments where exposure limits are different for the various
emitter frequencies and in classified environments.
The majority of the 8700 series probes have four-inch (10 cm)
diameter heads. The minimum measurement distance for
these probes is about 4 inches (10 cm) from the outside surface
of the probe. Measurements made at closer distances can
result in inaccurate readings due to capacitive coupling. The
Models 8721D, 8723D, and 8725D have two-inch (5 cm)
diameter heads that can be used as close as 2 inches (5 cm)
from the source to the outside of the probe. These probes are
ideal for the measurement of waveguide leaks. Similarly, the
Model 8781D has a one-inch (2.5 cm) diameter head with a
flexible shaft that is designed for locating leaks in densely
packaged microwave systems.
Shaped Frequency Response Probes
The goal in designing and manufacturing a traditional, “flat”
frequency response probe is to make the probe equally
responsive to energy at every frequency within its rated
frequency range. In contrast, Narda’s patented shaped
frequency response probes are designed and manufactured so
that their sensitivity mirrors a particular standard as closely as
possible. For example, many of the major standards in the
world set limits for maximum exposure at the lowest frequencies
of 100 mW/cm2. These same standards typically limit exposure
in the VHF region to 1 mW/cm2and to 5-10 mW/cm2in the
microwave region. A shaped frequency response probe
designed for such a standard is 100 times more sensitive in the
VHF region than at the lowest frequencies. The result is that
energy from all sources within the probe’s rated frequency
range are not only summed in terms of RMS power but are also
weighted in direct proportion to a particular standard's
frequency dependent exposure limits.
FLAT
RESPONSE
OR SHAPED
FREQUENCY
RESPONSE
SIZE AND
MINIMUM
MEASUREMENT
DISTANCE

11Chapter 3 Probe Selection
The readout on the 8718B is shown in terms of Percent of
Standard. The full scale of Narda’s shaped probes is typically
either 300% or 600% of a standard. This permits measurements
of exposure environments where the weighted field strengths
range from as high as three to six times the maximum
permissible exposure (MPE) level to environments where the
levels are less than one percent of the MPE.
Connecting a Probe
Connect a cable with a quick-release, eight-pin connector to the
connector at the top of your Model 8718B. This cable will be
either (1) a short adapter cable for attachment to older style
8700 series probes with integral cables or (2) a 4 ft. (1.2m) long
cable with a quick-release connector on both ends for use with
the 8700 "D" series probes. The D series probes have a
quick-release, eight-pin connector that allows the probe to
attach directly to your 8718B or be used with a cable
A direct connection can be useful for certain low frequency
measurements. See Low Frequency Measurements in the
Applications Booklet.
8718B
8718B
8718B
8700D Series Probe
8700D Series Probe
8700/8700B Series Probe
Direct Connection
4' (1.2m) cable
Model 8744-04 (supplied)
1' (0.3m) adapter cable
P/N 2178770 (optional accessory)
It is important to un-
derstand that each
shaped frequency re-
sponse probe model
is designed
to conform to a par-
ticular standard.
Note

12 Operating the Meter
Probe Identification
Narda 8700D series probes use the following
labels and indicators:
•Certified Calibration Date Label
•Model Identification Label
•Color Band to Indicate the Full Scale
Measurement Range (20 mW/cm2
probes do not have a colored band)
•Calibration Label With Frequency
Correction Factors
Field Type (E or H)
Full Scale Measurement Range
Model Number
Standards (Shaped Probes Only)
Frequency Range
Serial Number
Correction Factor Listed for
Every Calibration Frequency
Model Number and Serial Number

13Chapter 4 Making a Measurement
4Making a Measurement
See Chapter 5,
Using the Menu
System, for details
on features and
operation.
Introduction
This chapter will help you make measurements with your Model
8718B. Information is included for turning the meter on,
selecting, zeroing, and testing a probe, plus an explanation of
the main measurement screen of the meter. Some general
information is also included about measurement surveys,
precautions you should observe, and the use of probe
correction factors.
Getting Started
Press the On power key. The meter model, serial, and firmware
version will be displayed briefly. After a few seconds, the
Opening Menu Screen will appear.
To Make Measurements...
1. Select the probe you want to use and connect it to
the meter.
2. Proceed as directed in Entering the Probe Model.
To access the meter’s menu system to perform some other
function...
1. Press F4 (MENU). The First Menu Screen will appear.
See Chapter 5, Using the Menu System.
CAL DATE 09 / 01 / 98
CAL DUE 09 / 01 / 99
CONNECT PROBE NOW
MEASURE MENU
F1 F2 F3 F4
CALIBRATION DATE
• Indicates date the meter
was last calibrated
CALIBRATION DUE DATE
•Indicates recommended
date for next calibration
Note

14 Operating the Meter
Entering the Probe Model
Narda's 8700 Series system is completely modular — all 8700
series meters work with all 8700 series probes. The single most
important thing you must do is tell the 8718B meter which probe
you are using.
The Model 8718B has the basic characteristics of every 8700
Series probe stored in its internal memory. All you have to do is
select the correct model number and the meter automatically
sets the correct scales.
The Model 8718B can also store the specific calibration
details for up to six probes.This includes the probe serial
number, calibration date, and the calibration factors marked on
the handle of the probe. Probes with this additional detail stored
in the meter are referred to as probes in memory.
Putting probes into memory has several advantages:
•It makes it easier to select a probe
•Data that is downloaded after using a data logging mode
will include a record of the probe’s calibration date and
its serial number.
•It makes using frequency correction much easier.
Probes are put into the meter’s memory using a personal
computer:
•By Narda on the day of shipment for all probes shipped
at the same time as the meter.
•By you at any time when you use the User's Software
supplied by Narda and a personal computer. Refer to
Chapter 18, User's Software for detailed information
regarding computer operations.
The single most im-
portant thing you
must do is tell the
8718B meter which
probe you are using.
Note

15Chapter 4 Making a Measurement
To select from the PROBES IN MEMORY...
1. If you haven’t already, press F1 (MEASURE).
2. The model number and the serial number of the last
probe used will be displayed on the second line of the
display. If you want to use the same probe, press
Enter.
3. If you want to use a different probe, look for the model
number in the positions above the F1, F2, or F3
legends. If more than three probes are in memory they
can be found by pressing F4 (MORE).
4. Press the appropriate function key and the probe
model and serial number will be displayed on the
second line of the screen. If this is correct, press Enter.
5. A new screen will appear specifying probe model
number, serial number, frequency range, field type,
maximum measurement range, and type of response
(flat or shaped). If this information is correct, press F1.
If this information does not match your requirements,
you need to select another probe. Press F2 and you
will go back to the Select Probe screen to make
another selection.
6. Proceed with the probe zeroing process. See Zeroing
the Probe on page 17.
SELECT PROBE
MODEL A8722 SND XXXXX
OR SELECT FROM L I ST
87XX 87XX 87XX MORE
F1 F2 F3 F4
A8742D S/N 00001
300 H -3GHzzkE-FLD
600 % STD SHAPED
YES NO MENU
F1 F2 F3 F4

16 Operating the Meter
To use a PROBE that is NOT IN MEMORY...
1. If you haven't already, press F1 (MEASURE).
2. The model number of the last probe used will be
displayed on the second line of the display. If you want
to use the same model probe, press Enter.
3. If you want to use a different model probe, select
PROBE by pressing F4. If more than three probes are in
memory, you will have to press F4 twice (MORE, then
PROBE). One of several screens that list all 8700 series
probes will appear.
4. If you see the model of the probe you want to use, press
the appropriate number key. The newer "D" series
probes are listed first.
5. If you do not see the model number you want, use the
7 (BACK) or 8 (NEXT) keys to page forward and
backward until you do. Press the appropriate number
key to select a probe model.
6. A new screen will appear specifying probe model
number, frequency range, field type, maximum
measurement range, and type of response (flat or
shaped). If this information is correct, press F1. If this
information does not match your requirements you need
to select another probe. Press F2 and you will go back
to the Select Probe screen to make another selection.
1 A8722D 5 A8732D
2 B8722D 6 A8742D
3 C8722D
4 D8722D 8 NEXT
F1 F2 F3 F4
You must return to
the Opening Menu
Screen and repeat
the probe selection
and zeroing process
if you want to
change probes.
Press 7 (Probe) from
the First Menu
Screen and then
press F4 (RESTART).
SELECT PROBE
MODEL A8722 SND XXXXX
OR SELECT FROM L IST
87XX 87XX 87XX PROBE
F1 F2 F3 F4
Note

17Chapter 4 Making a Measurement
Zeroing the Probe
The probe and meter must be “zeroed” together. It is important
that the probe is not exposed to radiated fields during the
zeroing process. The storage case is shielded and provides a
convenient “zero density” environment.
To zero the probe...
1. Place the probe in the storage case. Be careful not
to move the probe while zeroing takes place (on
probes with low frequency test points, you can create
static which will give inaccurate results).
2. When you are ready, press the ENTER key. The
screen will say ZEROING.
3. The meter will beep and the main measurement screen
will appear in about 15 seconds after zeroing is completed.
If you get a message that the probe could not be zeroed, the
most likely causes are:
•The probe is not connected properly. Check the
connector and retry.
•The meter is set for a fiber optic input and you are
using the standard cable input (or vice versa). Turn the
meter off. Turn the meter back on and press
(F4) (MENU) to access the menu system. Press
8(NEXT) to get to the Second Menu Screen. Press
3 (CABLE/FO) to the probe input status. Press F1 (OK)
if it is correct or F4 to select the alternate. Then press
Esc to return to the Opening Menu Screen.
7. Proceed with the probe zeroing process.
A8722D SNXXXXX
300 H -50GHzzkE-FLD
300 % STD SHAPED
YES NO MENU
F1 F2 F3 F4
Position the probe in
the case with one
test point pointed
downward and the
other two test points
above the foam.
This will insure that
the test points are
not touching the
foam.
Note

18 Operating the Meter
•The field strength is not low enough. Move away from
the RF field source, use the storage case to zero the
probe.
•The probe is damaged. Try another probe.
To reconfirm the zero while the instrument is in use...
1. Establish a zero density environment for the probe as
before.
2. Press the Auto Zero key. This will automatically “touch
up” the zero and correct for any drift in a few seconds.
Measurement Display Screens
There are two display screen options:
•The Main Measurement Display Screen.
•The Alternate Measurement Display Screen.
Main Measurement Display Screen
The Main Measurement Display Screen shows a maximum value
on the third line of the display. The Alternate Measurement
Display Screen provides frequency-specific, real time information
instead of a maximum value.
See Chapter 12,
Probe Zero,
for additional infor-
mation on the char-
acteristics of
the survey system
including the causes
of zero drift.
Note

19Chapter 4 Making a Measurement
Main Measurement Display Screen
(Shaped Probes)
12.1 % STD
27.5 MAX CF 1.00
ALT MAXR MENU FREQ
F1 F2 F3 F4
FIELD STRENGTH
•Indicates actual measured value
•Unit of measure is always % STD
for shaped frequency response
probes
BAR GRAPH
•Indicates approximate
field strength
•100 segment, three
10:1 (10 dB) ranges
MAXIMUM VALUE
•Indicates the
maximum value that
has occurred since
you began making
measurements or
since resetting the
maximum using
F2 (MAXR)
•The unit of measure is
the same as for the
instantaneous value
shown on the line
above.
PROBE FREQUENCY
CORRECTION
•CF = 1.00 indicates
no correction factor is
being applied
•CF= X.XX indicates
the numeric value that
is being applied
•A frequency displayed
here indicates that the
meter is applying a
correction factor
based on the stored
calibration data for the
specific probe in use.
F1
Change to the
Alternate
Measurement
Display Screen
F2
Reset the
Maximum Value to
the current Field
Strength displayed
on the second line
F3
Go to the First
Menu Screen
F4
Allows you to enter
or change the
frequency that you
are correcting for
probe frequency
deviation
Main Measurement Display Screen
(Flat Probes)
The Main Measurement Display Screen for flat frequency
response probes is the same as the screen for shaped
frequency response probes except as indicated below.
6.26 /Wmcm
2
11.5 MAX CF 1.00
ALT MAXR MENU FREQ
F1 F2 F3 F4
FIELD STRENGTH
•Indicates actual
measured value
•Unit of measure can be
changed by going to the
First Menu Screen