TB 9-6670-258-35
(2) Connect oscilloscope between TP1 (red lead) and TP5 (black lead) (fig. 7). If
indication on oscilloscope is not less than 1.5 V p-p, perform b (l) below.
(3) Set CELL SELECTOR switch to CELL 2 position.
(4) Adjust ZERO control for null indication on TI null meter.
If indication on
oscilloscope is not less than 1.5 V p-p, perform b (2) below.
(5) Set CELL SELECTOR switch to CELL 3 position.
(6) Adjust ZERO control for null indication on TI null meter.
If indication on
oscilloscope is not less than 1.5 V p-p, perform b (3) below.
b. Adjustments
(1) Adjust R1 (fig. 7) for minimum waveform amplitude on oscilloscope. ZERO
control (front panel) must be adjusted simultaneously to keep the meter at 0 indication.
(2) Adjust R2 (fig. 7) for minimum waveform amplitude on oscilloscope. ZERO
control (front panel) must be adjusted simultaneously to keep the meter at 0 indication. (R)
(3) Adjust R3 (fig. 7) for minimum waveform amplitude on oscilloscope. ZERO
control (front panel) must be adjusted simultaneously to keep the meter at 0 indication. (R)
15. Load
Test Alternate
Technique (Reference)
a. Performance Check
(1) Place TI cell No. 1 in lower adapter (if required) as fabricated in figure 6. Place
TI cell No. 1 in universal calibrator (force) with load cell No. 4.
(2) Place CELL SELECTOR to CELL 1 position and verity a null indication.
(3) Using universal calibrator (force), apply a load of 50,000 pounds to TI cell.
Rotate POUNDS thumbwheels to obtain a null indication on TI null meter. The procedure
for adjusting POUNDS thumbwheel is as follows:
(a) Adjust MSD (left thumbwheel) until meter pointer swings across null indication.
(b) Move MSD back one digit so that meter pointer swings back across null.
(c) Repeat (b) above with second and third thumbwheel.
(d) Adjust final thumbwheel for an exact null indication.
(e) Read weight directly from POUNDS thumbwheel, 50,000 125 pounds.
(4) Exercise load cell No. 4 and TI cell to full capacity three times.
(5) If POUNDS thumbwheel indication is not within limits, perform b (l) below.
(6) Decrease universal calibrator (force) setting to 10,000 pound indication on TI.
Check cell indication at each step; apply force at 10,000, 15,000, 20,000, 30,000, 40,000, and
50,000 pounds. Indications on TI and load cell indicators will be within 25 pounds for
10,000 pounds and 0.25 percent from 15,000 to 50,000 pounds.