OHAUS EC Series, Service Manual

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CHAPTER 3 SCALE TESTING AND CALIBRATION
3.6.3 Off-Center Load Test
The Off-Center Load Test is used to determine whether displayed weight values will be affected by moving
the sample to different areas of the weighing surface. See Figure 3-4.
This test must be performed using a single mass or the masses must be stacked.
1. Zero the scale.
2. Place a mass equal to 1/3 of the full-scale capacity in the center of the weighing surface. Press
the ZERO
button to return the reading to zero.
3. Slide the mass halfway between the center and the rear edge of the platform, and record the reading.
4. Slide the mass to the center of the weighing surface and press the ZERO button to return the reading
to zero.
5. Slide the mass halfway between the center and the left edge of the platform, and record the reading.
6. Slide the mass to the center of the weighing surface and press the ZERO button to return the reading
to zero.
7. Slide the mass halfway between the center and the right edge of the platform, and record the
reading.
8. Slide the mass to the center of the weighing surface and press the ZERO button to return the reading
to zero.
9. Move the mass halfway between the center and the front edge of the platform, and record the
reading.
10. Maximum reading should be less than or equal to the OCL specifications for the scale.
Reading toward Rear ____________
Reading toward Left ____________
Reading toward Right ____________
Reading toward Front ____________
Maximum Reading ____________
Figure 3-4. Off-Center Load Test Weight Locations.