Holtgreven Truck Scale Resources - Manual (Page 28)

PT300 Users manual
Rev G, Feb 2011
Page 28 of 44
1. Position the corner fixture with rubber pad on the scale position #1. Apply 2500 lbs to the
loading block. Annotate the reading.
2. Repeat for the #2 position.
3. If all readings are within 5 pounds and the previous calibration passed all of the readings
continue with the rest of the calibration verification. If the corner check fails go to the corner
adjust calibration procedure.
Scale Span Calibration
Tools required:
•
Calibration force generator; press or deadweights. This calibration source must cover the
range of 10% to 100% of nominal capacity with an accuracy of 0.25% of reading or better.
PT300
•
100027 - 8" (
±
0.25") x 8" (
±
0.25") x 1.75" (minimum) aluminum loading block.
•
100028-A - 8" (
±
0.25") x 8" (
±
0.25") x 0.5" (
±
0.125") rubber loading scale. (40 to 70 Shore A
rating)
PT300DW
•
100029 - 12" (
±
0.25") x 12" (
±
0.25") x 1.75" (minimum) aluminum loading block.
•
100030-A - 12" (
±
0.25") x 12" (
±
0.25") x 0.5" (
±
0.125") rubber loading scale. (40 to 70 Shore
A rating)
4. Bring the scales to the calibration site. If there is more than 5
°
F difference in temperature
between the scale temperature and the calibration site allow the scales to reach room
temperature.
5. Place scale on calibration fixture. Turn scale on. Wait 3 minutes for warm-up.
6. Apply test forces every 10% of the scales capacity and verify that the reading falls within 1% of
the applied force or 1 display division whichever is greater as shown in the sample table below.
20K Capacity
Test
force
(lb)
Lower
limit
(lb)
Upper
Limit
(lb)
0 0 0
2000 1980 2020
4000 3960 4040
6000 5940 6060
8000 7920 8080
10000 9900 10100
12000 11880 12120
14000 13860 14140
16000 15840 16160
18000 17820 18180
20000 19800 20200
0 -20 20
7. If any value is out of acceptable limits proceed to the adjust calibration procedure.
8. If all values are within acceptable limits unit passes calibration verification.