6
RoughDeck PW-1 Installation Manual
3.0
Adjustments and Calibration
3.1
Mechanical Adjustments
Jam nuts are not supplied for locking the feet due to a slight decrease in accuracy when the jam nuts are tightened.
If the scale application requires jam nuts to secure the feet, they may be added. The feet must be unscrewed beyond
the minimum height to allow room for the jam nuts between the foot pads and the load cells.
Adjust the Feet
1. Slightly lift the scale corner of the foot needing adjustment with a pry bar.
2. Turn the foot until it is contacting the floor
3. Repeat as needed until all feet are contacting the floor equally.
4. When height adjustments are complete, check level of the deck with a spirit level. The deck must be level
within 1/4".
When adjusting the scale feet, prevent the scale foot from bottoming out against the underside
of the load cell. In addition, the foot stem may be damaged by bending or stripping threads if
extended beyond the maximum height adjustment.
3.2
Corner Corrections
All
RoughDeck
scales are delivered with the junction box corner-trimmed; however, corner trimming is necessary
after replacing a load cell.
For this process, the indicator must be connected, calibrated and indicate an approximate weight value; an exact
weight value is not necessary. A test weight of 25% of scale capacity recommended for this procedure.
Example: 500 lbs for 2000 lb models, 5000 lbs for 20,000 lb models.
1. Remove the junction box cover and identify the correct load cell terminal corresponding to each corner,
labeled CELL 1, CELL 2, CELL 3 and CELL 4. See Figure 4-2 on page 9 for scale deck corner numbering.
2. With no weight on the scale, zero the indicator.
3. Turn all four potentiometers (shaded areas of Figure 3-1) until a clicking sound is heard from each
potentiometer. This ensures the maximum signal from each load cell.
4. Place the test weight on one corner and record the indicated weight.
5. Repeat Step 4 for each of the other three corners. The load cell with the lowest corner reading is used as the
reference point and will not be trimmed.
Figure 3-1. Potentiometers
6. Place the test weight on one of the other three corners and use that load cell’s potentiometer to adjust the
load cell output down to the reference cell output.
7. Repeat Step 6 with the other two high output corners.
Adjustments are somewhat interactive, and adjusting the three higher outputs may affect the reference cell output,
especially in smaller scale decks. Rezero the indicator and repeat the test until all corners read within ±0.1% of the
test weight used.
Important
CELL 1
CELL 4
CELL 2
CELL 3
INDICAT OR
+EX
–EX
+SI
–SI
100 K
+SE
–SE
+EX
+EX
+EX
+EX
–EX
–EX
–EX
–EX
+SI
+SI
+SI
+S
I
–SI
–SI
–SI
–SI
SHD
SHD
SHD
SHD
23126
Rev. A
SHD
JU1
JU2
JU3
JU4
100 K
100 K
100 K
