HD Electric CDM-50 User manual

CABLE
DISTANCE
METER
SPECIFICATIONS*
PERFORMANCE
Accuracy 0.5% ±2 digits
Resolution (less than 33’) 0.25” (5mm)
Resolution (more than 33’) 0.5” (10mm)
Minimum gap between wires 6” (150mm)
Operating Temp. Range 14° F to 104° F (-10° C to 40° C)
Battery Life 50,000 measurements (Long Life
Alkaline type)
Measurement units Imperial (feet/inches) or metric
(meters)
Auto power off delay 3 minutes
Dimensions 8.5” x 4” x 3”
(205mm x 100mm x 70mm)
Weight 1.1 lb. (0.5kg)
Item Order No.
Cable Distance Meter, take measurements for 6 wires up to a distance of 50
feet (15m), includes carrying bag
CDM-50
Cable Distance Meter, take measurements for 6 wires up to a distance of 75
feet (23m), includes carrying bag
CDM-75
ORDERING INFORMATION
Troubleshooting
The following is a list of actions to be taken if the
unit is not working properly:
Screen is blank
Check to make sure the battery is inserted correctly.
Open battery door on the bottom rear of the unit.
The battery is inserted with the terminals on the
inside. The + and - symbols on the battery should
match the corresponding + and -symbols on the
inside of the battery compartment.
Unit does not measure all wires
Ensure that horizontal distances between wires are
within the sonic beam, as shown in the Performance
section of this manual.
Incorrect readings
Ensure the Calibrate mode switch is in correct
position, i.e. CABLE for cable height measurement,
and WALL for horizontal distance to object
measurement. Ensure no walls or similar
obstructions are within 7 feet (2m) of either side of
the unit, as reflections from these can interfere with
correct operation.
Warranty
Each unit is guaranteed against malfunction caused
by faulty components or manufacture for a period of
12 months from the date of purchase (excluding
battery). At HD Electric Company’s sole discretion, it
will be decided either to repair, modify or replace the
unit. Should the Cable Distance Meter develop a
problem, contact HD Electric Company. For further
information, contact:
HD Electric Company
1475 Lakeside Drive
Waukegan, IL 60085 USA
Phone: [phone]
Fax: [phone]
Web: www.HDElectricCompany.com
HD Electric Company is committed to ongoing review and improvement of its
product lines, and thus reserves the right to modify product design and
specifications without notice.
HD Electric Company products are available through HD sales representatives
worldwide.
Printed in U.S.A. © HD Electric Company 2004 Bulletin No. CDMInstMan-100
Operating and
Instruction
Manual
Models
CDM-50
CDM-75
* Based on ambient temperature of 68° F (20° C)
Model
CDM-50
Model
CDM-75
1 inch (25mm) Cable Diameter 10’ - 50’
(3m – 15m)
10’ - 75’
(3m – 23m)
0.5 inch (12mm) Cable Diameter 10’ - 50’
(3m – 15m)
10’ - 50’
(3m – 15m)
0.25 inch (5.5mm) Cable Diameter 10’ - 40’
(3m – 12m)
N/A
0.125 inch (2.5mm) Cable Diameter 10’ - 33’
(3m – 10m)
N/A
No. of wires measured 6 6

Introduction
The Cable Distance Meter is a unique, handheld
instrument, primarily used for the measurement of the
height of overhead cables. The Cable Distance
Meters measure up to 6 cables.
The CDM-50 model measures to a height of up to
50 feet (15m). The CDM-75 model has an increased
range of up to 75 feet (23m).
The unit operates by transmitting an ultra-sonic signal
towards the wires, and measuring the time it takes to
pick up the echo from that signal. It automatically
compensates for the fact that the speed of sound
varies with temperature by monitoring the ambient
temperature using the internal temperature sensor.
The display continuously shows the ambient
temperature reading. Because the temperature sensor
reacts relatively slowly to large temperature changes, it
is necessary to wait about a minute after taking the
meter suddenly from a warm to a cold environment
before taking a measurement, e.g. taking the unit from
inside a warm vehicle to outside.
To make a measurement
1. Select the required measurement units by setting
the switch at the back of the unit to display in feet and
inches (I) or meters (M).
2. Set the Calibrate switch to the CABLE position.
2. Press the ON key to power on the unit.
3. Position unit directly under the cable(s) to be
measured.
4. Press the MEASURE key to take a measurement.
The distance to the first cable is shown in the Height
Measurement location in the display. If there is more
than one cable present, the difference in height
between each cable is stored in memory.
5. Press the READ CABLES 1-6 key to display each of
the cable height differences stored in memory (Stored
Measurements).
The unit will automatically turn off 3 minutes after the
last key has been pressed.
Hints & Guidelines
Position the unit on the ground, directly underneath the
cable to be measured. Align the unit in the direction of
the cable, with the cone pointing towards the cable, as
shown.
When taking cable measurements, ensure that
there are no walls or buildings within a distance
of 7 feet (2m) on either side of the meter, as
reflections from these will distort the readings.
Also ensure there are no trees or other
overhanging objects in the vicinity.
When measuring more than one cable, ensure
that none of the cables are outside the sonic
beam, as shown in the Performance section of
this manual. If the cables are not vertically above
one another, this could be the case. In this
instance, it will be necessary to take a number of
separate readings from different positions.
Water and moisture can cause the Cable
Distance Meter to malfunction. Therefore, the
meter should not be used in rain or snow. If
water does get into the cone, leave it upside
down in a dry, warm area.
If the display shows - - -.- - -, this indicates a
“poor target” and normally happens when the
cables are moving due to wind, etc. Wait until
the wind dies down to get an accurate reading.
Calibrate Mode
The Calibrate mode switch allows the user to
periodically check the unit to ensure that it is still
operating within specification. For cable distance
measurement, this switch should be in the
CABLE position. When the switch is put to the
WALL position, horizontal measurements to
large objects, e.g. walls, can be taken.
When the unit is first used, a horizontal reading
to an object, e.g. wall, from a fixed position
should be taken. The reading should be entered,
together with the date, into the table below.
Whenever the unit is to be checked for accuracy,
a reading should be taken from the same point,
noting the result and date in the table. If the
reading is outside of specification, the unit
should be returned to HD Electric for calibration.
Date
Reading