5.5 Non-linearity
Most three-point tension meters employ only linear characterization and
have large errors at the midpoints (up to 15%). The CTM uses multi-point
segmenting to correct for non-linearity, reducing it to less than 0.2%.
Table of Contents
1.0 Introduction .........................................................................................................................3
5.6 Wire Characteristics
6.0 T roubleshooting
Creep Every material including steel exhibits creep under load. It will
neck down over time, quite quickly over the fi rst few seconds
and much slower as time progresses. A wire cable also sees
creep from the wire spacing and wind. This effect is seen as a
display that drifts lower after it has been clamped in line.
Variations Material that varies in diameter or shape will have different
output at the same tension
Strands The best cable assembly is one that is perfectly round, as
it will not change contact geometry with the wire twist. The
closer the wire cable cross section appears to be round, the
better the measurement performance will be.
Problem Possible Cause Solution
Powers on momentarily and turns off
Does not power on Low battery Replace with high quality alka-
Display is
completely dark
Display drifts downward once installed
Temperature not
accurate
Low battery Replace with high quality alka-
line batteries
line batteries
Batteries installed
backwards or no
spring contact
Software reset Remove battery cap & reinstall
Display contrast too
light
Display contrast too
dark
Wire material is
creeping and internal friction between
wires is relieved.
Instrument changed
temperature environments
Instrument exposed
to sun
Insure that positive terminals
of both batteries (nub) face inward – towards the black cap.
Check that spring is attached
to the battery cap.
after one minute. Attempt to
turn power on again.
Hold the Right Arrow key down
while pressing the F2 key
several times to increase the
display contrast. If nothing occurs, release both keys. Press
the power button and try again.
Hold the Arrow key down while
pressing the F1 key several
times to decrease the display
contrast.
This is normal behavior of
wire. Lower display resolution
to mask this effect.
Allow instrument to remain in
environment until temp stabilizes or enter temp manually
Enter temp manually
1.1 Unpacking ...................................................................................................................3
1.2 Description ..................................................................................................................3
1.3 Important features .......................................................................................................4
2.0 Operation 5
2.1 Typical Operation ........................................................................................................5
2.2 Measurement Practices ..............................................................................................6
2.3 Softkey Functions .......................................................................................................7
3.0 Confi guration Mode ............................................................................................................11
3.1 Accessing the Confi guration Mode ...........................................................................11
4.0 Changing Sheaves .............................................................................................................14
5.0 Achieving Best Accuracy ....................................................................................................15
5.1 Accuracy ...................................................................................................................15
5.2 Calibration to Specifi c Wire Type ...............................................................................15
5.3 Loading Error ............................................................................................................15
5.4 Non-repeatability .......................................................................................................15
5.5 Non-linearity ..............................................................................................................16
5.6 Wire Characteristics ..................................................................................................16
6.0 Troubleshooting ..................................................................................................................16
16
1
Specifi cations
Power
2 AA, common alkaline batteries. Operational battery life over 40 hours at
room temperature. Battery life is reduced at lower temperatures.
5.0 Achieving Best Accuracy
The CTM is an instrument designed to give accuracy that typically exceeds
5.1 Accuracy
normal requirements for wire tensioning. You should have an understanding
of what factors affect tension measurement accuracy.
Display
Operational keys
Operational annunciators
Temperature detection
Display resolution
Dot graphic LCD display
Power, Wire, Escape/Clear (Esc), Next ( ) and four softkeys with changing fuction and label, depending on the specifi c menu in use
Unit of measure, battery level
Temperature accuracy approximately ±2° F (±1°C)
2,000 lbf/ 1,000 kgf/ 10,000 N CTM instrument:
Displayed resolution setting
Low Med High
lbf (pound-force) 10 lbf 5 lbf 2 lbf
kgf (kilogram-force) 5 kgf 2 kgf 1 kgf
N (Newton) 50 N 20 N 10 N
Custom units between 101 &
200 divisions
8,000 lbf/ 3,500 kgf/ 35,000 N CTM instrument:
Displayed resolution setting
Low Med High
lbf (pound-force) 50 lbf 20 lbf 10 lbf
kgf (kilogram-force) 20 kgf 10 kgf 5 kgf
N (Newton) 200 N 100 N 50 N
Custom units between 101 &
200 divisions
between 201 &
500 divisions
between 201 &
500 divisions
between 501 &
1000 divisions
between 501 &
1000 divisions
5.2 Calibration to
Specifi c Wire Type
Contact your distributor for any
additional calibrations you may
need.
While it is best to have the instrument calibrated to the specifi c wire size(s)
and type(s) used, the CTM can often work adequately in other situations. If
the best tension accuracy is required, it is recommended that a calibration
be performed for that specifi c wire size and type.
What calibration choice and sheaves should I use?
Situation
Exact wire size
and type is
shown in wire list
Wire size is
same, but type is
not identical
Wire size is not
the same
Do not use the CTM to measure tension for wires if both of the following are
true:
1. No wire calibrations are stored of the same diameter as the wire you are
looking to measure, and
2. You do not have sheaves of the same diameter.
If both of these conditions exist, contact your distributor.
Wire calibration
selection
Description of
exact match
Description of
same wire
diameter
Closest diameter
Sheave
selection
Sheaves noted
in list
Sheaves noted
for that wire size
Sheaves match-
ing the wire size
being measured
Accuracy
Best
Good
Fair
Available options
Operating environment
Dimensions
Weight
For ease of use, the display always counts by a multiple of 1, 2 or 5.
Varied wire sizes
Suitable for outdoor use
10˝ x 23˝ x 3˝ (25 cm x 59 cm x 8 cm) approximately
11 lb (5 kg) approximately
2
5.3 Loading Error
5.4 Non-repeatability
Contact your distributor to improve accuracy for a specifi c wire type by
calibrating to it.
A tensiometer works by defl ecting the cable, which makes the cable path
longer than when a tensiometer is not installed. When the tensiometer is
removed, the wire tension decreases as the cable length is restored. This
effect is known as loading error. The CTM design elongates the cable by a
mere 0.08 inch (2 mm), making loading errors extremely small.
The CTM’s sheave with bearing design provides the best mechanical
performance. It is also superior at detecting tension that is being added or
removed.
15
4.0 Changing Sheaves
1.0 Introduction
Do not use the CTM with cable
larger than indicated on the
sheaves. Overload and damage to the instrument may
result.
Do not mix sheave sizes. This
will result in inaccurate measurement and possible overload.
As you use the CTM on different diameter cables you must change to the
correct sheave size. To change sheaves, remove the hex head screws
pointed out in Figure 6 below. Replace the sheaves with the correct letter
sheave and reinsert the screws and tighten.
Insure sheaves installed agree with sheaves noted in the Wire calibration.
Exception: Sheaves match the wire diameter of the cable to be measured
and alternate calibration is selected as per section 5.2.
Insure that the wire rope is riding in the groove of all three sheaves.
Screws
1.1 Unpacking
This manual covers the setup and operation of the CTM Clamp Line Tensiometer. The CTM is a simple, accurate strand dynamometer. It is can be
clamped onto a cable, accurately determine the wire tension and be removed in seconds.
The CTM can handle multiple wire diameters, it can display live tension, dual
live/peak tension, average tension captured from several tests, dual tension/
temperature display and a check-tensioning graphical display.
With its battery-powered electronic interface, setup and operation is made
simple with on-screen prompts.
This manual covers the following:
• Unpacking
• Setup
• Operation
• Maintenance
• Troubleshooting
When you receive your CTM, unpack it and inspect the container and the
instrument for any damage. Report any problems to the shipping company
immediately and save the packing materials.
Insert 2 AA batteries into the battery compartment, shown in Figure 1. Your
CTM probably comes from the factory with the proper sheave size installed
and calibrated for your application. If not, follow the setup directions later in
section 3.0 Confi guration Mode and 4.0 Changing Sheaves.
Figure 7
Changing sheaves
1.2 Description
Figure 1
The CTM is shown in Figure 1 with the parts labeled.
Sheaves
Support arm
Lever arm
Front panel
Battery
compartment
14
3
1.21 Front Panel and Keys
The front panel of the CTM is shown in Figure 2.
Figure 2
CTM front panel
Following are descriptions of the keys and their functions:
ON/OFF key. Press this key to power up and turn off the
CTM.
Default password is 0. If a new
password is lost or forgotten,
contact your distributor.
• Enable C - Enable or disable Centigrade temperature.
• Enable F - Enable or disable Fahrenheit temperature.
Off Press this softkey to enable or disable the auto-shutdown. If
you enable this function you are prompted to set a period of
time in minutes. Next, press the Enter softkey to accept this
value. You are then asked to set the shutdown type; Fixed, No
Load, or No Change. These are described below;
Fixed - The unit will shutdown after the set number of minutes no
matter what happens.
No Load - The unit will shutdown after the set number of minutes
only if there is no load on the unit. This prevents shutdown in the
middle of line tensioning.
No Change - The unit will shutdown if there has been no keypad
activity or change in tension after the set number of minutes.
ChPwd Press this key and you are prompted to enter a new pass-
word to access the confi guration menus. Use the softkeys
to scroll in a new password and press the Enter softkey to
accept it.
Reset Press this key and you are asked if you wish to reset the sys-
tem. Press the Yes softkey only if you want to reset the unit
to factory default confi guration. Press the No softkey to abort
this and return to the previous screen.
1.3 Important features
ESC key. Press this key to escape an area of the menu or
to clear the fi eld when in data entry mode.
WIRE key. Press this key to change the wire diameter you
are testing with the CTM. Choose from the listed selection
and when the desired size is highlighted, press the ENTER
softkey. Up to 15 sizes available.
Soft key. Softkey function changes as needed for different
tasks. The soft key labels appear above the keys themselves. You will use these for operation and confi guration.
Arrow key. Press this key to reveal more softkeys in a group
of softkeys.
Quick to use Attaches and removes from tensioned line in
seconds.
Quick-tensioning readout for ultra fast line tensioning.
Direct tension readings No more complicated lookup charts! Save time
and improve accuracy.
Portable & rugged Designed for outdoor use.
Accurate Employs Weigh Bar® technology used for pre-
cise weighing.
Multiple wire size storage Stores up to 15 different calibrations.
4
13
Custom units of measure are
handy when working with multipart lines.
The softkeys in the Confi guration mode are Wire, Setup, Reso, Comm,
Mode, Units, Power, ChPwd, and Reset. These are described below:
Wire Press this softkey and the wire selection screen is displayed.
Choose an existing wire to change its defi ning characteristics.
You have the choice of changing the Range, which is used to
set the check-tensioning function, or the Rating, which is the
maximum rating of the cable.
Range - Use this item to set the parameters for the check tension-
ing display. Follow the prompts to set the following:
Lower tension limit - This is the lowest acceptable force
Upper tension limit - This is the highest acceptable force
Units - Unit of measure used in defi ning the tension limit
Rating - Press this softkey and you are prompted to set the ulti-
mate rating for the cable being used and the unit of measure for
that rating.
Setup Press the Setup softkey to view the Setup softkeys. This is
the same as the Setup softkey described in 2.31 Top Level
Softkeys.
Reso Press the Reso softkey and you are prompted to enter a
display, or count-by, resolution. Choose from Low, Medium or
High.
Low resolution provides the best stability and makes the
display easiest to read. High resolution provides the fi nest
graduations, but sees greater drift from wire creep and nonrepeatability. If the reading is decreasing over time or differing between measurements on the same line, lowering the
resolution will reduce these effects.
Comm Communication output not supported at this time in the CTM
Mode Press this softkey to set the display mode on power up.
Choices are Last*, Temp, Check, Avg, Peak, and Force.
Use the Sel keys to display your choice and press Enter to
accept it.
Units Press this softkey to set the following:
• Unit of measure on power up. Choices are Last*, C2, C1, N, kgf,
and lbf. Use the Sel keys to display your choice and press Enter
to accept it. C2 and C1 are custom units. If you choose to have
custom units, you are prompted to enter the number of pounds in
each custom unit. The CTM will then automatically calculate correct display for the applied force.
• Enable lbf - Enable or disable the pound-force unit of measure.
• Enable kgf - Enable or disable the kilogram-force unit of
measure.
• Enable N - Enable or disable the N unit of measure.
• Enable CUST1 - Enable or disable the Cust1 unit of measure.
• Enable CUST2 - Enable or disable the Cust2 unit of measure.
2.0 Operation
2.1 T ypical Operation
Take readings at three different
places along the cable, moving
the tension meter at least four
inches for each reading. Take
the average of the readings.
The built-in average function is
ideal for this task.
The handle quick release pin
should be used when the CTM
is attached to a cable that will
be de-tensioned and retensioned. The pin prevents the
handle from opening once the
tension falls to a small level.
The pin should also be used if
the CTM will be installed for a
prolonged period.
Press the WIRE key to list the
stored calibrations.
Typical operation of the CTM is covered below, followed by explanations of
the various display modes, how to change wire size, how to change the unit
of measure, etc.
To perform a typical tension measurement, see the Tip in the left column and
follow these steps:
1. Turn the unit on by pressing the ON/OFF key. . .
The screen shows the following:
Mode
Te
Unit of
measure
7
f
b
l
n
o
i
s
n
Wire
size
6
6
1
/
X
1
9
Battery
level
Force
reading
Zero Clear Mode
Avg
Figure 3
Sample display
2. This example shows the wire is a 7/16”, 6X19 stranded cable and the
unit of measure is lbf. Place the CTM so the two outside sheaves hang
on the wire. Insure that the wire rope is riding in the groove of all three
sheaves. See Figure 4. Press the Zero softkey to zero the display.
0 should be displayed.
3. Raise the lever arm until it locks in the upright position to apply tension
to the wire. Read the line tension on the display.
4. Release the lever arm and you are ready to perform another measure-
ment.
12
5
2.2 Measurement
Practices
Do not apply tension greater
than rated capacity of the
instrument or overload damage
to the sensor may result.
Do not use the CTM with cable
larger than indicated on the
sheaves. Overload and damage to the instrument may
result.
Do not mix sheave sizes. This
will result in inaccurate measurement and possible overload.
For best measurement, install the CTM at least 2 feet (0.6 m) from terminations, clamps or other hardware. Do not install over the top of wire wrappings.
Take readings at three different places along the cable, moving the tension
meter at least four inches for each reading. Take the average of the readings.
The built-in average function is ideal for this task.
Do not use the CTM to measure tension for wires if both of the following are
true:
1. No wire calibrations are stored of the same diameter as the wire you are
looking to measure, and
2. You do not have sheaves of the same diameter.
If both of these conditions exist, contact your distributor.
Contact your distributor to improve accuracy for a specifi c wire type by cali-
brating to it.
Insure that the wire rope is riding in the groove of all three sheaves.
Insure sheaves installed agree with sheaves noted in the Wire calibration.
Exception: Sheaves match the wire diameter of the cable to be measured
and alternate calibration is selected as per section 5.2.
The CTM has an internal temperature sensor inside the electronics cavity. Dramatic temperature changes (such as moving from a warm vehicle to
cooler outdoors) requires time for the sensor to reach the same temperature.
Direct sunlight will heat the electronics cavity and cause higher readings
than actual ambient temperature. In these cases, use a seperate thermometer to determine temperature. Be certain to enter this temperature into the
CTM if using the quick-tensioning mode with the temperature dependent
acceptance window.
For best tension accuracy, use the exact temperature of the wire. This may
be widely different from the ambient temperature if the cable has been sitting
in direct sunlight.
3.0 Confi guration Mode
3.1 Accessing the
Confi guration Mode
The Num keys increment and
decrement the displayed numbers. The Adv key moves the
cursor to the next digit position.
Default Confi guration pass-
word is 0. If a new password is
lost or forgotten, contact your
distributor.
You need to access the Confi guration mode to perform certain tasks. Access
to some of these tasks may be restricted by a supervisor password.
To access Confi guration mode:
1. From normal operating mode, press the Right Arrow softkey
2. Press the Confi g softkey. . .
3. Use the Num and Adv keys to enter the Confi g password. Default is 0.
A new softkey set, shown below, appears:
1
9
X
lb
n
o
i
s
n
Te
Units Temp Setup
The following is displayed:
d
r
o
w
s
s
a
P
Num Num Adv
After the number is displayed, press the Enter key. . .
The following is displayed:
ig
f
n
o
C
6
6
1
/
7
f
Config
_
0
:
Enter
ig
f
n
o
C
Wire Setup Reso
Comm
Wire Setup Reso
4. The unit is now in the Confi guration mode. To see the rest of the softkeys
available in this mode, press the Right Arrow key. All the Confi g softkeys
are shown below.
g
i
f
n
o
C
Mode Units Power
Comm
ChPwd
n
o
C
Reset
ig
f
6
11
About Press this softkey to see the following information:
Device - Press this softkey to show a list of information about the
CTM, such as -- serial number, capacity rating, hardware and
software revision levels. Press any key to return to the previous
softkey set.
Calib - Press this softkey to show Calibration Points and the cali-
bration information for the current wire size. Follow the on-screen
prompts.
O. Load - Press this softkey to show an audit count of the number
of times the unit has been overloaded beyond 125% of capacity.
Press any key to return to the previous softkey set.
Zero - Press this softkey to show the deadload anaylsis of the
CTM. Press any key to return to the previous softkey set.
Ntwrk - Not used in the CTM.
Test Press this softkey and the following softkeys appear:
Batt - Press this softkey to test the battery level.
A-D - Press this softkey to display the A to D counts.
Disp. - Press this softkey to perform a test of the display pixels.
Keys - Press this softkey to test the keypad.
Comm - Not used in the CTM.
Ntwrk - Not used in the CTM.
2.3 Softkey Functions
2.31 Top level softkeys
Now that you’ve seen a simple operation, we’ll explain the softkey functions.
Figure 5 shows the softkeys available during normal operation.
6
1
/
7
f
b
l
n
o
i
s
n
Te
Zero Clear Mode
1
9
X
6
Press
Avg
Te
Units Temp Setup
1
9
X
6
6
1
/
7
f
b
l
n
o
i
s
n
Config
Figure 5
Normal mode softkeys
Zero Press this softkey to zero the force display. You would usually press
this at the beginning of a series of tension tests but would not need
to do it for every test unless there is some zero drift.
Clear Press this softkey and you are prompted to clear the Peak read-
ing or the Average. Make your choice by pressing the appropriate
softkey and that value is cleared from memory.
Mode Press the Mode key to scroll through the fi ve display modes. These
are explained below:
Confi g This is a password protected menu. See section 3.0.
Press the ESC key to return to the normal operating mode. If you made
changes to the confi guration of the unit, you are prompted to save them or
abort the changes. Do so and the unit returns to normal operation mode.
Live T ension Mode: The display shows the live tension.
Dual Peak Mode: The display shows the live tension on the top display and the peak force achieved on the bottom display. To clear the
peak remove any force on the CTM, press the Clear softkey and
follow the prompts.
Average Capture Mode: This mode shows the live tension in the
top display and the average of all captured readings on the bottom
display. To capture a reading and add it to the average, press the
Avg softkey when a force is applied to the CTM. Follow the prompts
to add (or not) the reading to the average.
Temperature Mode: This mode shows the live tension in the top
display and the current temperature in the bottom display. Also
shown is whether the reading is in Fahrenheit or Centigrade and if
the temp is one that was Entrd (entered) manually.
You can enter the temperature in one of two ways; let the CTM determine the ambient temperature automatically or key in a temperature manually. Instructions for entering the temperature are under
the Temp softkey description.
10
7
Upper and lower thresholds are
set in the Confi guration WIRE
menu.
Check-tensioning Mode: Check-tensioning mode permits quick &
easy graphical view of the applied tension versus the desired tension. This mode works well when you are repeatedly tensioning to
the same tension range. This mode displays a bar graph representation of the tension being applied. See Figure 5. The black bar represents the range of the wire, from zero to ultimate wire rating. The
wide white band is the tolerance window based on upper and lower
thresholds you can enter. The live force is represented by the arrow
and the white line on the black bar. When the force gets within ±5%
of the acceptance window, a close-up of the acceptance window is
displayed. See bottom example in Figure 6.
Temp Press this softkey to choose the source of the temperature reading,
the CTM itself (Meter), outside input (Input) or None. If you choose
Input, you are prompted to enter the temperature. When fi nished,
press the Enter softkey to accept this value.
Next you are prompted to choose Fahrenheit or Centigrade as the
temperature unit. When your choice is highlighted, press the Enter
softkey.
An annunciator shows when temperature has been manually entered. See example below:
The CTM has automatic tension targeting with temperature. Points
may be entered from a linear Tension-Temperature supplied table
for a wire cable. If entered, the check-tensioning window will automatically fl oat according to the active temperature (manual or
automatic). Use the bottom and top entries from the table. Patent is
pending on this feature.
1
9
X
6
6
1
/
7
f
b
l
n
o
i
s
n
Te
1960
Display when tension is
below the dotted, target box.
Te
UNDER
b
l
n
o
i
s
n
1
9
X
6
6
1
/
7
f
5700
Display when tension falls
within the dotted, target box.
Figure 6
Check-tension display
To exit the check-tension mode, press any softkey to display the
softkey labels, then press the Mode softkey to scroll to the next
mode. The next mode is the fi rst mode that was described, live ten-
sion mode.
Avg Press the Avg softkey to add a displayed tension to the average of
other entered readings. Follow the onscreen prompts.
Press the Right Arrow key to move to the next set of softkeys.
Units Press this key to set the CTM for displaying:
• Force in lbf, kgf or N
• Size of wire in inches or millimeters
• Temperature in Fahrenheit or Centigrade
Auto-off can preserve battery
life.
Te
n
io
s
n
lb
1
/
7
f
1
9
X
6
6
1200
Temp F
Entrd
Zero Clear Mode
Temperature Display Mode
Setup Press the Setup softkey and you will see these choices; Off, Pt-
Fmt, Misc, About, and Test. These are described below:
Off Press this softkey to enable or disable the auto-shutdown
function. If you choose Yes, you are asked to set a period of
time in minutes. Next, press the Enter softkey to accept this
value. You are then asked to set the shutdown type; Fixed, No
Load, or No Change. These are described below;
Fixed - The unit will shutdown after the set number of minutes no
matter what happens.
No Load - The unit will shutdown after the set number of minutes
only if there is no load on the unit. This prevents shutdown in the
middle of a test.
No Change - The unit will shutdown if there has been no keypad
activity or change in tension after the set number of minutes.
PtFmt Not currently used.
Misc Press this softkey to set the following:
Flash - Enables or disables the momentary blinking of the display
to acknowledge a key press.
Zero - Enables the use of the Zero softkey to clear a peak tension
value.
Contr - Press this key to adjust the contrast of the LCD display.
Press the Up soft key to lighten the contrast. Press the Down soft
key to darken the contrast.
There is a keypad shortcut for increasing and decreasing contrast.
While in normal display mode press the Arrow key and the 2nd
softkey simultaneously to increase contrast. Press the Arrow key
and fi rst softkey simultaneously to decrease contrast.
Blite - Not currently used.
58. 0
Avg
8
9
CHECK•LINE
CTM Tension Meter
Operating Manual
®
BY ELECTROMATIC
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