Tiedown load cells

05dec17


Load cells (top)

locations,history

loadCellNaming
      conventions

Picture notes:


Load Cell locations By Date
date
td12-1
td12-2
td4-1
td4-2
td8-1
td8-2
171128 (4)
installed
260310
90409
90410
260311
260312
253850
171115
failed after
1606 hf run


failed
170829

replaced cable (3)
160317


90410 09458 90407 253850
09jun11 (1)
k147697
(90408)
replaced with??
(90409)
90410
09458
90407
90459
06oct09
147697
replaced with ??
90410
09458
90407

23jun08
147697 207629
90410 90458 90407 90459
14nov06
147697
90409 90410 90458 90407 90459
14aug98
90408
90409
90410
90458
90407
90459
xxjan16 (2)
90408 90409 90410 90458 90407 253850



Load cell calibration


Load cell resistances measured at input to amp.  (top)

     The wheatstone bridge in the load cells has 4 wires that go to the amplifier in the td box. The are labeled: Ex+,Ex-,Sig+,Sig-. If you remove these cables at the amplifier you can measure the load cell resistance. This is a quick way to check if the load cell is healthy. It also will show problems in the cable from the loadcell to the box and the db25 connector that brings the cable into the box (it contains filters that can blow out).

In the table below:
        amp 1 is the top    amplifier
        amp 2 is the bottom amplifier
        cable 1 normally goes to the top amp
        cable 2 normally goes to the bottom amp
see the drawing in the td manual for where the load cell is located on the yoke.

To do the measurement:

  1. turn off amplifier
  2. remove the 4 wires that go to the amplifier.
  3. remove tension on the load cell by raising the  jack. Point the  dome point at the tiedown.
  4. measure the resistance at the 4 wires that connect to the amp.
  5. The sparcarrestor,and db25 filter should be in place.

resistance values for loadcell cables at input to loadcell amplifier
td,ldcell,cable Ex+ to 
Sig-
Ex+ to 
Sig+
Ex-to 
Sig-
Ex- to 
Sig+
Ex+ to
Ex-
In+ to
In-
date/notes
4-2.90458
351.2
351.0
351.2
1050.0


01dec17 (in lab after removal)
12-1,90408
352.4
1048.0
350.6
359.0


01dec17 (in lab after removal).
8-1,90407
264.8
265.
265
265
343
356
14nov17. (-200mv offset.. bad)
8-2,253850
268
269
267
267
357
355
15nov17. loadcell ok.
8-2 ,90459 269.33
268.60
268.10
268.70


13jan16 (2)
12-1,90408
267.6
267.9
267.9
267.7


9jun11
12-2,90409
267.5
267.2
268.4
267.5


9jun11
8-1  ,90407
268.1
268.8
268.6
268.6


9jun11
8-2 ,90459
268.8
268.8
268.4
268.5


9jun11








12-1,90408 289.7(1) 268.6 267.6 267.5

09nov06 (1)
12-1,90408 267.9 268.4 267.6 267.9

17jan05








12-2,90409 264.2 264.4 264.5 264.5

09nov06
12-2, 90409 267.1 267.5 268.2 268.1

17jan05








4-1,90401 267.8 268.2 267.8 268.2

02sep05++
4-1,90410 267.3 268.7 267.8
237.4** 
267.5

17jan05
4-1,90410,1 268.4 267.7 268.9 270.4

31oct01








4-2,90458 264.8 264.9 264.9 265.1

02sep05++
4-2,90458 264.2 264.3 264.7 264.7

17jan05
4-2,90458 264.5 264.6 264.9 265.0

31oct01








8-1,90407 268.2 269.6
357.6**
268.8 269.7

02sep05 ++
with filter
8-1,90407 268.1 267.9 268.3 268.3

17jan05
8-1 ,90407,1 268.0 268.3 269.1 269.3

31oct01








8-2,90459 268.6 268.6 268.1 268.2

02sep05 ++
8-2,90459 268.7 268.6 268.6 268.3

17jan05
8-2,90459,2 268.5 267.4 268.2 268.3

31oct01
8-2,90459,1
When db25 filter bad
264.2 352.3 ** 352.4** 268.2

31oct01

The values with ** had bad filters in the db25 connector.
++ removed the filter because it was bad (and had no spares)


Load cell amplifiers:



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