Megger Digiflex Com User manual

Digiflex Com
Kommunikationsnetze
Communication Networks
Elektrizitätsnetze
Power Networks
Rohrleitungsnetze
Water Networks
Leitungsortung
Line Location
- Date of release: 2003/30 -
EN
Mess- und Ortungstechnik
Measuring and Locating Techniques
Instruction Manual

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Digiflex Com
compact and light-weight
Time-Domain Reflectometer

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TABLE OF CONTENTS
1.GENERAL...................................................................................................9
1.1ADVICEFROMMEGGER..................................................................................9
1.2TERMSANDCONDITIONSOFWARRANTY...........................................................10
1.3SAFETYINSTRUCTIONS..................................................................................11
1.4INDICATIONSUSEDINTHEDESCRIPTION............................................................12
2.TECHNICALDESCRIPTION........................................................................13
2.1GENERALDESCRIPTION.................................................................................13
2.2SPECIFICATIONS...........................................................................................15
2.3ITEMSSUPPLIEDANDOPTIONALEXTRAS..........................................................19
3.OPERATION.............................................................................................21
3.1MEASURINGTERMINALS...............................................................................21
3.2DISPLAY.....................................................................................................22
3.3FUNCTIONSOFKEYSANDROTARYENCODER.....................................................24
3.4GETTINGSTARTED(INSERT/REPLACEACCUMULATOR).......................................27
3.5SWITCHINGONANDOFF..............................................................................27
3.6MAINMENU..............................................................................................28
3.7COMPENSATIONOFINITIALREFLECTION...........................................................28
3.8HOWTOLOCATEAFAULT.............................................................................29
3.8.1FieldsofApplication........................................................................29
3.8.1.1FaultsCausingaNegativeReflection.....................................................30
3.8.1.2FaultsCausingaPositiveReflection.......................................................30
3.8.1.3FurtherFieldsofApplication..................................................................32
3.8.2TestingaCablewithKnownNominalVelocityofPropagationNVP
orwithKnownPulsePropagationVelocity(v/2).............................................32
3.8.3HowtoDetermineanUnknownNominalVelocityofPropagationor
PulsePropagationVelocity.............................................................................34
3.8.4SimplificationofFaultLocationUsingComparativeTests..............34
3.8.5Averaging........................................................................................35
3.8.6ModeNEXT.....................................................................................36
3.8.7ModeIFL........................................................................................37
3.8.8DistancedependingAmplitudecorrection......................................37
3.8.9HowtoUsetheMarker...................................................................38
3.8.10ChangeofPulseWidth....................................................................39
3.8.11SelfTest...........................................................................................40
3.9MEMORYFUNCTION....................................................................................41
3.10SERIALINTERFACE........................................................................................43

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4.NIMHACCUMULATORCHARGER..............................................................45
4.1CHARGINGTHEACCUMULATOR.....................................................................45
4.2GENERALINSTRUCTIONSONHOWTOHANDLEANIMHACCUMULATOR...............45
4.2.1SafetyPrecautions..........................................................................46
4.2.3PracticalHints................................................................................46
5.CAREANDMAINTENANCE.......................................................................47
6.APPENDIX................................................................................................49
6.1LISTOFABBREVIATIONSUSED.......................................................................49
6.2CONVERSION:NVPV/2...........................................................................50
6.3TABLE:NVPANDV/2FORCOMMONTYPESOFCABLES.......................................50
6.4GLOSSARY.................................................................................................52

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EC - Declaration of Conformity
CE Mark
We, the company Megger
Kabelmesstechnik GmbH
Roederaue
D-01471 Radeburg
Germany
declare under sole responsibility that our product
Digiflex Com
is in conformity with the directive of the Council of European Communities for
the Harmonization of the Laws of Member States on Electromagnetic
Compatibility (EMC Directive 89/336/EEC) and Low Voltage (Directive
73/23/EEC).
This EC Declaration of Conformity is the result of a verification test performed
by the department of Quality Assurance of Megger Kabelmesstechnik GmbH.
Conformance with the directive on Electromagnetic Compatibility was verified
in accordance with the following standards:
EN 50081 Interference Emission, EN 50082 Interference Immunity
EN 55011 Product Standard, EN 61000-4-2 Electrostatic Discharge, and
EN 61000-4-4 Fast Interfering Electrical Transients
Conformance with the directive on Low Voltage was verified in accordance
with the following standards:
EN 61010-1 Safety Regulations for Electrical Measuring, Control, Regulating,
and Laboratory Instruments and EN 60529 Enclosure Protection
Radeburg, 13th of March 2003
Dr. Iann
Managing Director

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1. GENERAL
1.1 Advice from Megger
The present system manual has been designed as an operating guide and
for reference. It is meant to answer your questions and solve your
problems in as fast and easy a way as possible. Please start with referring
to this manual should any trouble occur.
In doing so, make use of the table of contents and read the relevant
paragraph with great attention. Furthermore, check all terminals and
connections of the instruments involved.
Should any question remain unanswered or should you need the help of an
authorized service station, please contact:
Megger Limited Seba Dynatronic
Mess- und Ortungstechnik GmbH
Archcliffe Road
Kent CT17 9EN
T: [phone]
F: [phone]
E: [email protected]
Dr.-Herbert-Iann-Str. 6
D - 96148 Baunach
T: [phone] – 0
F: [phone]
E: [email protected]
Hagenuk KMT
Kabelmesstechnik GmbH
Megger USA
Röderaue 41
D - 01471 Radeburg / Dresden
T: [phone] – 0
F: [phone]
E: [email protected]
Valley Forge Corporate Centre
2621 Van Buren Avenue
Norristown, PA 19403 USA
T: [phone]
F: [phone]
Megger
All rights reserved. No part of this handbook may be copied by photographic or other means
unless Megger have before-hand declared their consent in writing. The content of this
handbook is subject to change without notice. Megger cannot be made liable for technical or
printing errors or shortcomings of this handbook. Megger also disclaims all responsibility for
damage resulting directly or indirectly from the delivery, supply, or use of this matter.

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1.2 Terms and conditions of warranty
Megger accept responsibility for a claim under warranty brought forward by
a customer for a product sold by Megger under the terms stated below.
Megger warrant that at the time of delivery Megger products are free from
manufacturing or material defects which might considerably reduce their
value or usability. This warranty does not apply to faults in the software
supplied. During the period of warranty, Megger agree to repair faulty parts
or replace them with new parts or parts as new (with the same usability and
life as new parts) according to their choice.
This warranty does not cover wear parts, lamps, fuses, batteries and
accumulators.
Megger reject all further claims under warranty, in particular those from
consequential damage. Each component and product replaced in
accordance with this warranty becomes the property of Megger.
All warranty claims versus Megger are hereby limited to a period of 12
months from the date of delivery. Each component supplied by Megger
within the context of warranty will also be covered by this warranty for the
remaining period of time but for 90 days at least.
Each measure to remedy a claim under warranty shall exclusively be
carried out by Megger or an authorized service station.
This warranty does not apply to any fault or damage caused by exposing a
product to conditions not in accordance with this specification, by storing,
transporting, or using it improperly, or having it serviced or installed by a
workshop not authorized by Megger. All responsibility is disclaimed for
damage due to wear, will of God, or connection to foreign components.
For damage resulting from a violation of their duty to repair or re-supply
items, Megger can be made liable only in case of severe negligence or
intention. Any liability for slight negligence is disclaimed.
Since some states do not allow the exclusion or limitation of an implied
warranty or of consequential damage, the limitations of liability described
above perhaps may not apply to you.

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1.3 Safety Instructions
All persons involved in the installation, operation, maintenance and repair
of the Digiflex Com must have read this manual carefully.
The Digiflex Com and its supplementary equipment are in accordance
with the current state of safety technology at the time of delivery. Owing to
the work processes involved, however, there may be parts of the unit and
its peripherals which cannot be given optimum protection without an
unreasonable reduction in function and usability. Good personal safety
practice is therefore indispensable in terms of the protection of staff and the
unit.
Therefore, please comply with the following safety instructions!
GENERAL INSTRUCTIONS
Work on the Digiflex Com and its peripherals must only be carried out by
trained and/or instructed staff. Other persons must be kept away.
This manual must be available for the supervisory, operating and
maintenance staff to refer to.
Improper use may endanger life and limb, the Digiflex Com and connected
equipment, as well as the efficient functioning of the unit (accident
prevention regulations). The Digiflex Com may only be used for the
purpose for which it is intended by the manufacturer.
Always use the correct tools in perfect condition for all work.
Regular checks must be made to ensure that the relevant safety
regulations are being complied with during operation and maintenance.
Never operate the Digiflex Com and its peripherals if they are not in a
technically perfect condition.
Only parts specified by Megger as accessories must be used for the
Digiflex Com and its peripherals, as the necessary safety will not
otherwise be guaranteed. No mode of working which detracts from the
safety of the Digiflex Com must be used.
Replace a accumulator only when the device is switched off and
disconnected.

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The user is under an obligation to report any changes in the Digiflex Com
to the supervisor responsible without delay.
The operator is under an obligation to shut the Digiflex Com down
immediately in the event of a malfunction which detracts from the safety of
staff. The Digiflex Com must only be put back into operation once the
malfunction has been rectified.
ELECTROTECHNICAL INSTRUCTIONS
Connect the Digiflex Com and all its accessories according to instructions
and regulations. Make sure the relevant regulations such as EN, DIN, VDE
or national standards, respectively, are observed.
Repair and maintenance work must only be carried out when the unit is
switched off (dead) and then only by a skilled electrician in accordance with
current accident prevention regulations. A skilled electrician in the sense of
the accident prevention regulations is a person who can assess the work
assigned to him/her and recognise possible dangers on the basis of his/her
technical training, knowledge and experience, and of his/her knowledge of
the relevant regulations.
1.4 Indications used in the description
Important instructions concerning personal protection, work safety and
technical safety are indicated as follows:
CAUTION
Caution indicates work and operating procedures which
must be complied with in full to prevent the Digiflex Com
and/or its peripherals from being damaged or ruined.
NB
NB indicates special technical requirements to which the
user must pay particular attention when using the Digiflex
Com.
Equipment protected by double insulation or reinforced
insulation.

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2. TECHNICAL DESCRIPTION
2.1 General Description
The Digiflex Com is a compact, light-weight and easy-to-handle digital
time-domain reflectometer for locating faults in balanced
telecommunication and control lines. It can be handled easily and so
enables even an inexperienced user to locate faults precisely and fast.
Experts in testing will find a variety of additional functions at their hands. By
its design the Digiflex Com is a robust device suitable for field application.
The Digiflex Com is double-insulated and equipped with safety terminals to
protect the user.
The Digiflex Com is similar to radar in that it employs the pulse reflection
technique. Suitable test pulses are transmitted into the cable to be tested.
The pulses travel along the cable at a propagation velocity that is
dependent on the connected test object. In every place where the electric
characteristics of the cable have changed, part of the transmission pulse is
reflected and caused to travel back to the Digiflex Com where it will be
displayed on the screen with a time delay corresponding to its propagation
time.
A change in the electric characteristics of a cable may be caused either by
a possible fault or by local circumstances such as junction boxes,
connectors, or the end of the cable. The time delay between the incoming
reflection and the moment of pulse transmission is the propagation time to
the point of fault and back. The distance from a place of interest can be
calculated by taking into account the specific pulse propagation velocity of
the cable under test. Shape and size of the reflected signal allow
conclusion to be drawn on the nature and size of the fault. Cable
attenuation can be compensated for by applying a distance-dependent
amplitude correction (amplitude correction) in order to display echoes from
different points of reflection with comparable amplitudes irrespective of
their distance. In this way the Digiflex Com shows a revealing picture of the
connected cable. There is even a mode called IFL to locate any fault that is
inconsistent in its time structure.
The propagation time of the test pulse which is dependent mainly on the
material of cable insulating material is taken into account by specifying a
signal propagation velocity.

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For measuring the distance to the fault, a movable cursor or a combination
of marker and cursor are used. Distance is display in m, ft, or µs as
selected by the user. In order for the distance to be indicated in m or ft, the
pulse propagation velocity of the cable under test has to be entered before
the test is carried out.
The greatest advantage of the pulse reflection method is its ability not only
to find out that there is a fault but also to find its location and type.
The Digiflex Com allows two cables under test to be connected to L1 and
L2 at the same time and to show two reflectograms simultaneously. This
can be done using currently taken reflectograms or test results stored in
memory.
The most important modes of testing are:
Reflection measurement Pair (physical circuit) versus Built-in balancing
network (dummy line)
Difference measurement of two pairs
Location of crosstalk (NEXT) Pair versus Pair (k1 measurement)
Measurement of time-variable (intermittent) faults (IFL)
There are two display modes the user can choose between. When you
wish to get a revealing overview of the cable under test and, at the same
time, have a closer look at a cable section, you can choose the display
mode which divides the screen of the Digiflex Com into two windows. The
upper window shows the full distance range with a movable window
marking a section the content of which is displayed zoomed in the lower
window. There is yet another display mode with a full-screen display of the
selected cable section.
Current device settings are display by the LCD. When a stored
reflectogram is uploaded as trace 1, all relevant settings such as gain and
NVP are also taken over from memory thus allowing the current test result
to be easily compared with a reflectogram taken earlier.
The Digiflex Com is powered from a NiMH rechargeable accumulator fitting
in a accumulator compartment in the bottom of the unit. The instrument has
a Power-Down mode. Moreover, the unit can also be powered from an
external source of power.

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2.2 Specifications
Modes of testing:
L1:
L2:
Alt:
Diff:
NEXT:
Reflection test of cable connected to
socket L1 versus built-in balancing
network
Reflection test of cable connected to
socket L2 versus built-in balancing
network
A reflection test is carried out alternately on
cables connected to sockets L1 / L2
Measurement of difference between
cables connected to sockets L1 and L2
Location of crosstalk between cables
connected to sockets L1 and L2
Pairs to be connected: 2
Modes of operation:
Single
Cont
Average
IFL
Single test
Continuous testing
Averaging of up to 256 test results
for intermittent faults (Intermittant Fault
Location)
Measuring ranges at
v/2= 100 m/µs
50, 100, 200, 400, 1000, 2000 m
4, 7.5, 15, 30 km
(zoomed 5 m)
Zoom factors (X direction) 1, 2, 5, 10, 20
(depending on range of measurement)

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Maximum resolution 1.25 cm for range 50 m at 50 m/µs
2.5 cm for range 50 m at 100 m/µs
2.5 cm for range 100 m
5 cm for range 200 m
10 cm for range 400 m
25 cm for range 1000 m
50 cm for range 2000 m
1 m for range 4000 m
2.5 m for range 7500 m
5 m for range 15 km
10 m for range 30 km
Accuracy ± 0.1% of range of measurement
1 cursor step
Gain 0 … 80 dB in steps of 1 dB
Dynamic range 90 dB
Distance-depending
amplitude correction
settable in 99 steps
Distance reading m, ft, or µs
Setting range of signal
propagation velocity
NVP
v/2
0.200 … 0.999 in steps of 0.001
30.0 … 149.9 m/s or
98.4 … 491.8 ft/s
Pulse amplitude 5 ns 2 V25 % at 120 
10 ns 2 V25 % at 120 
20 ns 2 V25 % at 120 
50 ns 3,5 V25 % at 120 
200 ns 5,0 V25 % at 120 
750 ns 6,0 V25 % at 120 
3 µs 6,5 V25 % at 120 

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Pulse width Pulse width is linked to range of
measurement:
5 ns for range 50 m (100 m/µs)
5 ns for range 100 m
10 ns for range 200 m
20 ns for range 400 m
50 ns for range 1 km
200 ns for range 2 km
200 ns for range 4 km
750 ns for range 7,5 km
750 ns for range 15 km
3 µs for range 30 km
Electrical strength of test
inputs
250 V AC/DC 50/60 Hz
CAT II (overvoltage category)
Memory locations 50
Measuring rate up to 11 reflectograms per second
(averaging mode, short range)
Display rate up to 4 screen images per second
Display 256 x 128 pixels, back-lighted
Interface RS 232 for PC / printer
Power supply Replaceable NiMH rechargeable
accumulator (7,2 V/2,2 Ah)
or Plug-in mains unit (optional extra)
Mean operating time with
one accumulator charge
ca. 6 hours
Languages German, English,
other languages as optional extras on
request

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Environmental conditions
Operating temperature
Storage temperature
Storage temperature
(accumulator)
-10 °C … +50 °C
-20 °C … +60 °C (without accumulator)
-20 °C … +50 °C
Dimensions, mm 176 x 260 x 70 (L x W x H)
186 x 260 x 70 incl. measuring terminals
Weight approx. 1.5 kg
Interelement protection
class
II with accumulator compartment closed
and protective cap on serial interface
terminal
Enclosure protection IP54
Subject to changes and alterations without further notice!

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2.3 Items Supplied and Optional Extras
Items supplied:
Description
Digiflex Com, consisting of
Digiflex Com (G,E, two languages on request)
- 2 pcs. set of test leads
- Case for Digiflex Com
- Accumulator 7,2 V / 2,2 Ah / NiMH
- Charger
- Plug-in mains unit for charger;
100 … 240 V, 50/60 Hz
- Instruction manual, according to
country:
German
English
More languages on request

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Optional Extras:
Description for use as
Rechargeable accumulator
7,2 V / 2,2 Ah / NiMH
replaceable accumulator
Winkis Com PC software for evaluating and
storing reflectograms
Printer set means for the on-site preparation
of test reports
Transportation case for printer set
Plug-in mains unit external source of power
Adapter cable for charging the accumulator
from a vehicle electric mains
using the charging management
of the charger case
Coax adapter for testing coaxial cables
Fault Converter for locating moisture-induced
faults
Calibration with manufacturer’s
test certificate
Subject to changes and alterations without notice!