10
For proper weight reading, the signals reaching the indicator must be
identical no matter where a weight is placed on the scale. Getting these
signals to match is called corner balancing the scale.
Your goal is to get the readings from the weight sensors to match. You do
not have to get the correct weight reading at this point. That is taken care of
when you calibrate your indicator. (See the
Service Manual for your indica-
tor.) One potentiometer affects one weight sensor. You balance the weight
sensors by adjusting the corresponding potentiometer in the junction box.
This scale was corner balanced at the factory, but in a new installation it is
required that corner balancing and calibration be checked to ensure installa-
tion accuracy. Below are the steps you need to take to corner balance your
scale:
1a. Test load the deck in both directions by driving a loaded truck on and off
the scale 3 or 4 times.
1b. Check all mechanical hardware.
1c. Remove the junction box cover to access the potentiometers.
2.
To capture the value of internal zero for your particular indicator, refer to
your indicator's
Service Manual.
3.
Use test weights equal to 20-25% of full capacity and obtain a displayed
weight value for the test weight applied to each of the four weight
sensors, like this:
3a. Disable AZT on indicator.
3b. Place certified test weight directly above first weight sensor.
3c. Record displayed weight value.
3d. Repeat steps 3b and 3c for each weight sensor.
4.
If displayed weight values for all weight sensors equal each other, within
+/- 1 division, proceed to the calibration instructions for your indicator
found in
5.
If displayed weight value for any weight sensor varies from the others by
more than +/- 1 division, adjust the appropriate junction box potentiom-
eter by turning it the number of 360 degree turns indicated by this
formula:
If the Number Of Turns is a positive value, turn the potentiometer
clockwise. If Number Of Turns is a negative value, turn the potentiom-
eter counterclockwise.
6.
Repeat steps 3b and 3c followed by step 4 or step 5 until all weight
sensors equal each other, /- 1 division.
Corner Balancing