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Operating instructions
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Che mni tze r Str aße 11 092 17 Bu rgstäd t
Satelliten- und Kabelfernsehanlagen/Industrievertretung GmbH
SAT
Kabel
-
®
IRM 20
Pulse reflectometer
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©2017 SAT-Kabel GmbH ©2017 SAT-Kabel GmbH
1. General
Determining the length of a short and accessible cable is not a problem with a tape
measure.
But measuring a cable reel with several 10 or 100 meters is expensive and time
consuming.
Particular difficult is the determination of cables which are not easy accessible because of
the local conditions. For example, it is concealed in the wall.
For this purpose the IRM 20 offers an easy fully electronically measurement.
The length of the cable is displayed immediately after connecting. Only the cable type
have to be selected from a predefined list. Additional to the length an open end or short
circuit is identified. The length of an installed antenna cable can fast and easily
determined, e.g. for the invoice to a customer by a monteur. It also can be very helpful in
networking to check the segment length of a network. In addition it helps in localization of
damages on cables.
The distance to the defective point is displayed immediately and whether it is a short
circuit or a cut. The IRM 20 can measure all usual 2-core wires, no matter if it are coaxial
cables or "normal" installation cables.
Excepted from this are only some special cable types, e.g. high capacitive cables which
"swallow" the measurement impulses.
2. Delivery volume
Important notes
The working temperature range is 0 °C until +40 °C
cloth. Do not use any aggressive solvents!
®.
We thank you for buying of a product of the company SAT-Kabel
This operating instructions shall help you to understand the functions of the instrument and
to ease its use. If you have questions about this instrument or suggestions for further
improvements, please get in touch with us.
This instruction has been performed to the best of our knowledge. Developments and
technical amendments are subject to change without notice.
Topical made operating instructions in a PDF format can also downloaded from our Internet
homepage www.sat-kabel.de.
©2017 SAT-Kabel GmbH
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1. General
Determining the length of a short and accessible cable is not a problem with a tape
measure.
But measuring a cable reel with several 10 or 100 meters is expensive and time
consuming.
Particular difficult is the determination of cables which are not easy accessible because of
the local conditions. For example, it is concealed in the wall.
For this purpose the IRM 20 offers an easy fully electronically measurement.
The length of the cable is displayed immediately after connecting. Only the cable type
have to be selected from a predefined list. Additional to the length an open end or short
circuit is identified. The length of an installed antenna cable can fast and easily
determined, e.g. for the invoice to a customer by a monteur. It also can be very helpful in
networking to check the segment length of a network. In addition it helps in localization of
damages on cables.
The distance to the defective point is displayed immediately and whether it is a short
circuit or a cut. The IRM 20 can measure all usual 2-core wires, no matter if it are coaxial
cables or "normal" installation cables.
Excepted from this are only some special cable types, e.g. high capacitive cables which
"swallow" the measurement impulses.
2. Delivery volume
1× IRM 20
1× Measuring cable
1× 9-V-accumulator
Operating instruction
Important notes
! Measurement only on strain-free objects!
! Do not expose incident solar radiation, heath and extreme coldness!
The working temperature range is 0 °C until +40 °C
! avoid strains from impacts or drop downs
! the surface of the housing can be cleaned with a dry, soft and lintfree
cloth. Do not use any aggressive solvents!
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©2017 SAT-Kabel GmbH ©2017 SAT-Kabel GmbH
The IRM 20 operates based on the reflections of electric pulses on open or closed cable ends.
These electric pulses are send out in time constant intervals.
The device calculates the length of the cable by measuring the time between the sending of
the impulse and his return.
This depends on the velocity factor of the cable which is considered in the calculation.
The velocity factor (v/c or pulse velocity) declares the propagation of electrical signals in the
cable in relation to the speed of light. It depends on the used type of coaxial cable and can be
found, for example, in the manufacturer's data sheet for the cable in question. Alternatively it
has to be determined "at the place" (locally).
To make work easier the IRM 20 has a persistent memory with 20 predefined cable types and
their corresponding velocity factors. These can be modified.
3. Functional principle
3. Operation
3.1 Switch on/ off
3.2 Measuring
3.3 Velocity factor
3.3.1 Set a velocity factor
Press the key briefly
Press the Key briefly
Long press the key
and move the cursor
Press the key for
2 seconds
Press the key briefly again
BATTERY INDICATOR
IRM 20 operate
IRM 20 switched of
Without any key pressed the IRM 20 turns off automatically after 2 minutes to save battery.
If the battery voltage becomes lower than 5,8 V a battery icon appears in the display.
At a battery voltage of 5,5 V the IRM 20 switches off.
On switch on again the IRM 20 shows the last
used memory entry.
With the IRM 20 switched on press the key
briefly to select a memory entry between P1
and P30.
P0 … P9
P9 … P0
The cable to be measured must be connected only after selecting the required shortening
factor. Then read the length of the cable in the display. If there is a short circuit in the
cable, the cable length appears >>K<< in the display.
The velocity factor declares the propagation of electrical signals in the cable in relation to
the speed of light. It affects the accuracy of the measurement significant. The velocity
factor is in general:
Electric cable 0,49–0,57 (ca. 0,53)
Telephone cable 0,58–0,65 (ca. 0,62)
Coaxial cable with PE dielectric 0,66
Coaxial cable with foam PE 0,77–0,85 (ca. 0,83)
Air insolation 0,88–0,92
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3.3 Velocity factor
3.3.1 Set a velocity factor
Press the Key briefly
Press the key briefly
and change values ongoing
Long press the key
and move the cursor
press an hold key
for 5 seconds …
… until MENU appears
Notes
! the velocity factor of the cable has always to be selected before
the measurement of the length
! if the velocity factor is unknown, choose an approximate value
and determine the fault from both ends of the cable
! if a terminating resistor is installed which corresponds to the wave
impedance of the cable a length measurement is not possible
(the send pulse will not be reflected at the cable end)
! to minimize measuring errors determine the cable from both ends
The velocity factor declares the propagation of electrical signals in the cable in relation to
the speed of light. It affects the accuracy of the measurement significant. The velocity
factor is in general:
Electric cable 0,49–0,57 (ca. 0,53)
Telephone cable 0,58–0,65 (ca. 0,62)
Coaxial cable with PE dielectric 0,66
Coaxial cable with foam PE 0,77–0,85 (ca. 0,83)
Air insolation 0,88–0,92
After 8 s display
OFF
PROGRAMMING MENU
MEMORY ENTRY
P0 … P9
1| MEMORY ENTRY ON/OFF
2| VELOCITY FACTOR
(two decimal places 0,xx)
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©2017 SAT-Kabel GmbH ©2017 SAT-Kabel GmbH
4. Technical data
14. Guarantee
State July 2006
For this instrument will be granted a service life (in following called guarantee) to
following conditions:
Forms for service coverings and further information are found in the standard form
contracts under: www.sat-kabel.de
Press the key for
2 seconds
SAVE when the IRM 20 is switched off!
3.3.2 Determining the velocity factor
If the velocity factor of a cable is unknown it can determined easily.
Therefor connect a cable with a known length (50 to 100 meter) at the IRM 20.
After that, modify the velocity factor until the displayed length matches the length of the
cable
Maximal cable length 1000 m (low loss cable)
Resolution 1 m
Accuracy ±1 % ±2 m
Measuring connection 4 mm banana jack, 75 ohms
Output pulse 4 V Rechteck, 30 kHz
Display LCD, 2×8 Zeichen, illuminated
Casing dimensions 120 mm × 60 mm × 25 mm
Weight 110 g
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14. Guarantee
State July 2006
For this instrument will be granted a service life (in following called guarantee) to
following conditions:
+ This guarantee is valid for new instruments purchased in Germany.
+ New instruments and their components, which are defective because of
production faults and/or material faults, are repaired from SAT-Kabel®.
+ For wear parts, like accumulators, keyboards, housings, bags, connecting cables
this guarantee is valid for 6 month from the purchasing date.
+ The guarantee claim expires at matings by the purchaser or third persons.
+ At defects, caused by improper handling or operating, by wrong installation or
store, by improper connection or mounting, no guarantee is granted.
+ For not justified demand of our service we charge for our service the usual
payment for material, working hours and forwarding costs.
+ Repairs are only made with filled service covering.
Forms for service coverings and further information are found in the standard form
contracts under: www.sat-kabel.de
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Telefon: +49 (0)3724 6665-0
Telefax: +49 (0)3724 6665-44
[email protected] • www.sat-kabel.de
Irrtümer sowie Änderungen im Zuge technischer Weiterentwicklung vorbehalten!
©2017-04-07 SAT-Kabel®
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