UNWIND TESTER
MODEL UT-60
OPERATING INSTRUCTIONS
KERSHAW I N S T R U M E N T A T I O N I N C .
51 7 A u b u r n Ave .
Swedesboro, New Jersey, U.S.A.
08085
Phone: 856-467-5482
Fax: 856-467-2341
Operating Instructions
Tape Unwind Tester Model UT-60
01.
Description of Operation
This tester features a variable speed DC drive, a load cell to measure the
unwind tension, a digital meter to display the tension, and an analog output
for an optional strip chart recorder.
A slip clutch is coupled to the windup shaft to provide an over-running windup to take up slack as the material leaves the drive rolls. The web speed is
adjustable and the speed is indicated by the speed meter. The wind-up torque
is adjustable for the strength of the tape being tested. This torque is indicated
by the clutch torque meter in percent. The small digital counter displays total
tape travel in tenths of inches. This counter is activated by a pulse generator
driven by the drive shaft.
02.
Motor Controls
The Start push button will start the motor and the stop push button will stop
the motor.
The speed of the motor is adjusted by turning the speed potentiometer on the
console, and the speed is indicated on the digital display in feet per minute.
03.
Clutch Controls
The wind-up torque is adjusted by turning the clutch-torque potentiometer on
the console. This torque is indicated on the digital display in percent.
04.
Length Measurement
The length of tape is indicated in tenths of inches and can be reset to zero by
pressing the reset button.
05.
Load Cell Controls
A zero adjustment is provided to tare out any error at the beginning of the
test. This zero adjustment will zero both the digital display and the (optional)
strip chart recorder.
A selector switch is provided to set the tape width to be tested. This selector
switch will calibrate the digital display as if the tape were 1 inch wide. The
machine is currently calibrated as follows:
Switch Position
A
B
C
D
E
F
Width
1/2"
3/4"
1"
1 1/2"
2"
3"
Digital Display with
80 oz Test Weight
160
107
80
53
40
27
FIGURE 1
Strip Chart Recorder Output
The analog output for the optional strip chart recorder is directly connected to
the digital display and is also scaled with the tape width selector switch. The
recorder chart can be scaled by adjusting the range selector switch on the
front of the recorder as follows:
Range Selection
100 mV
200 mV
500 mV
Digital Display
100 ozs.
100 ozs.
100 ozs.
Recorder Pen
100%
50%
20%
FIGURE 2
The other features of the optional strip chart recorder are described in the
recorder manual.
Calibration Instructions
Tape Unwind Tester Model UT-60
CI.
C2.
C3.
Preparation
a.
Move the instrument console to a location where the operator has
access to both the front and rear of the instrument console.
b.
Remove the rear cover plate from the console.
Clutch Calibration
a.
Adjust the clutch-torque potentiometer on the front of the console to its
maximum.
b.
Adjust the clutch-torque span potentiometer located inside the
cabinet on the rear of the digital torque display until the digital display
reads 100%.
Speed Calibration
a.
Press the "Start" button to start the drive.
b.
Adjust the speed of the machine to an approx. operating speed.
c.
Use a hand tach. on the main drive rolls of the machine and note the
speed in R.P.M.
Note: The main drive rolls are 1 foot in circumference so 100 RPM
equals 100 feet/minute.
d.
Adjust the speed span potentiometer in the front of the console until the
digital display matches the tachometer reading.
Tension Calibration
a.
Remove the left hand drive roll from the drive shaft by loosening the 2
set screws and pulling the knurled roll off.
b.
Slide the 1 1/2" calibration bearing onto the drive shaft.
c.
Thread the calibration string (provided) along the webpath, over the
unwind sensing roll as shown in Diagram 1.
d.
Adjust the zero potentiometer until the digital display reads zero.
e.
Turn the drive on and adjust the speed to a crawl to break the static
friction in the machine.
f.
Hang a dead weight (5 lbs. = 80 ozs.) from the string as shown in
Diagram 1.
g.
Refer to Figure 1 from the Operating Instructions.
h.
Move the selector switch to position "A" and adjust the potentiometer
located inside the cabinet on the right hand side until the display reads
the correct reading, [see figure 1].
i.
Repeat this procedure for the other selector switch position using the
values in figure 1.
j.
The tester is now ready for operation.
UNWIND TESTER MODEL UT-60
CALIBRATION BEARING —
NOTE KNURLED DRIVE
ROLL HAS BEEN REMOVED
DRIVE ROLL
CALIBRATION STRIN6
SUPPLY ROLL
TAKE UP ROLL
CALIBRATION WEIGHT
LOAD CELL ASSEMBLY
DIAGRAM 1. CALIBRATION STRING WEB PATH
UT-60
UNWIND TESTER MODEL UT-60
DRIVE ROLLS
SUPPLY ROLL
TAKE UP ROLL
LOAD CELL ASSEMBLY
DIAGRAM 2, TAPE PATH
VT-60