SOP-TN-002 Rev. Q
T60 Operations and Service Manual
8
*Due principally to the uneven surface of the stranded cables, slight variations in readings may occur on the
same cable at the same tension. If closest possible accuracy is desired take three or five readings at slightly
different locations on the cable and average them.
4-8.
TYPE OF CABLE
-
The cable Tensiometer is calibrated for use on standard, multiple-strand, aircraft
cable of 7 x 7 or 7 x 19 stranding in sizes of 1/16, 3/32, and 7 x 19 stranding for 1/8 through 1/4
inch diameter on cable. Do not attempt to use the cable Tensiometer on cables of a different
construction. Cables construction and specification in accordance with MIL-DTL-83420, general
specification for flexible wire rope for aircraft control cables. See TABLE 5 for British Equivalent. The
Tensiometer instrument shall be calibrated on the same type of cables on which the Tensiometer
instrument will be used (such as coated cables used externally on helicopters). The T60 series cable
Tensiometer are standard calibrated on Flexible, wire rope, for aircraft control cables. Flexible cables,
either coated or non-coated, shall conform to MIL-DTL-83420. Most Aircraft systems use the Flexible
cable. Some aircraft, (A-10 and F-15), use both Flexible and Non-Flexible cables.
A Tensiometer
instrument calibrated on Flexible cable will not give accurate tension readings when measuring Non-
Flexible cable. Non-Flexible cables shall conform to MIL-DTL-87161, (Supersedes MIL-W87161 & MIL-W-
5693). Again, the Tensiometer instrument shall be calibrated on the same type of cables on which the
Tensiometer instrument will be used.
4-9.
USE OF CALIBRATION BAR -
A Calibration bar is supplied with each Tensiometer. This provides
an immediate means of checking the accuracy of the instrument while in use. The calibration bar has
been carefully checked to read the load marked on the identification tab. The identification tab also
carries the serial number of the instrument for which that particular calibration bar is provided. To
check calibration proceed as follows:
a.
Preset the indicator dial face to the smallest cable size listed, 1/16 for C8 and 1/8 for C9, 3cwt for
C8 and 10cwt for C9 British models.
b.
Grasp the calibration bar identification tab in the left hand.
c.
Place the bar in the instrument with the identification tab facing the user, and the right end of the
bar flush with the edge of the instrument. See Figure 4.
Figure 4- Calibration Bar Instruction
CALIBRATION BAR
FLUSH TO THIS
SURFACE
UP
DOWN
BOTTOM
RIGHT
TOP
LEFT
RISER
CABLE GAGE
POINTER LOCK BUTTON
PRESET ACTUATING
DIAL FACE
RING
HANDLE LATCH
POINTER UNLOCK
BUTTON
ACTUATING HANDLE
CABLE GAGE STOP PIN
SECTOR
JAW BASE
TAB
(under this cover)
d.
Slowly release the actuating handle, allowing the jaws to grip the calibration bar. Note the reading
on the dial indicator. The reading obtained in this manner should correspond with the reading
marked on the identification tab within +/- 2 % of the value marked. The T
ensiometer’s serial
number shall be marked on the bar.
Caution: The TEST BAR shall be placed flush against the riser faces such that the faces of the risers are parallel
with the test bar.
4-10.
OVERLOAD -
The cable Tensiometer is a durable precision instrument and cannot be damaged by
use on cables loaded in excess of the amount indicated by the dial on the Tensiometer.
