SOP-TN-002 Rev. Q
T60 Operations and Service Manual
10
SECTION VII
CALIBRATION
7-1.
EQUIPMENT REQUIRED -
C
alibrating the cable Tensiometer it will be necessary to have aircraft
cables of various sizes and a method of accurately loading these cables with a range of loads from 10
to 450 pounds.
7-2.
DISASSEMBLY PRIOR TO CALIBRATION -
(See Figure 6) Disassemble the instrument following
the order of the index numbers, starting with index number 1 down through and including index
number 10.
7-3.
CALIBRATION -
Calibrate the instrument as follows:
a.
Move post shaft (12) up and down and check for free movement and that the pointer returns to the
same position on the dial indicator each time.
b.
If binding or erratic indication occurs disassemble the instrument further to ascertain the cause.
c.
Check for free movement of sectors (24). There shall be 0.015-inch maximum clearance between
sectors (24) and frame (41). This is controlled by number of washers (25) placed under the sectors
(24).
d.
Place a washer (8) on each top pin of frame (41). Position mainspring (7) and secure with clips (6).
e.
Check that post shaft (12) just or almost contacts mainspring (7) and that mainspring does not
deflect shaft post and consequently pointer of dial indicator (35). If necessary, adjust position of
post shaft (12) on indicator shaft (13) by loosening setscrews (11) to obtain this condition. Be
careful not to get a false position. This can occur if indicator shaft (13) is not bottomed in dial
indicator (35).
f.
Position risers block (5). The riser block should not deflect the mainspring (7). If it does, select a
riser block with a low tolerance.
g.
Place clips (4) on the lower pins of frame (41). Between the pins and the top of the clip place a
0.010-inch shim (3) on each side of the instrument.
h.
Drop spring (10) onto shaft (13) and secure with screw (9).
i.
Check for a symmetrical bite. On a pre-loaded 7/32
”
cable, start to take a tension reading but do
not remove all restraint from handle. With the Tensiometer in this position, wiggle the cable with
free hand to determine that the resistance to movement is the same at both sectors (24). Add
shims (3) as necessary to balance bite. Add shims to obtain lower readings and remove shims to
obtain higher readings. Use shims that are 0.003 or 0.005 inch thick and place them on the bottom
of the pins. After the bite is balanced, place equal shim thickness on each side of the instrument
for subsequent calibration.
j.
Proceed with calibration by preloading the
7/32”
cable, with a load equal to the high end of the
instrument range. The high end is 200 lbs. for the type C8 and 450 lbs. for the type C9. Measure
the tension and add or remove shim (3) as necessary to make indicator read between 190-195 lbs.
for Type C8 and between 430-440 lbs. for the Type C9. Remember, the addition of shims (3) makes
lower readings. On the other hand, the remove of shims (3) makes higher readings. Try to set as
close as possible to 200 lbs. for type C8 and 450 lbs. for type C9.
k.
Proceed to verify calibration by preloading the
7/32”
cable with a load equal to the low end of the
instrument. Measure tension and add or remove shims (3) as necessary to make indicator read
between 75-80 lbs. for Type C8 and between 142-150 lbs. for the type C9.
