NCR 7870 manual Procedure 3 Decreasing Load Test

5-14 Chapter 5: Calibration

Procedure 3: Decreasing Load Test

This test checks the scale’s accuracy when incrementally removing weight from the Top Plate. Use weights that correspond to the NCR 7870 weight feature. If a failure occurs during this test, you must calibrate the scale again.

Note: This test must immediately follow the Over-Capacity Test; do not remove any of the weights prior to running this test.

Instructions

1.Select appropriate Weight Feature for your Scanner/Scale.

2.Follow the four steps shown in chart.

Step	Weight Feature	Add	Remove Weight	Display
		Weight
1	9.995 kg		2.495 kg	7.5 ±	0.005 kg
	13.995 kg		3.995 kg	10.0 ±	0.005 kg
	30.0 lb.		10.0 lb.	20.0 ±	0.01 lb.
2	9.995 kg		5.0 kg	2.5 ±	0.00 kg
	13.995 kg		7.5 kg	2.5 ±	0.00 kg
	30.0 lb.		15.0 lb.	5.0 ±	0.00 lb.
3	9.995 kg	0.1 kg	2.5 kg	0.1 ±	0.00 kg
	13.995 kg	0.1 kg	2.5 kg	0.1 ±	0.00 kg
	30.0 lb.	0.2 lb.	5.0 lb.	0.2 ±	0.00 lb.
4	9.995 kg		0.1 kg	0.0 ±	0.00 kg
	13.995 kg		0.1 kg	0.0 ±	0.00 kg
	30.0 lb.		0.2 lb.	0.0 ±	0.00 lb.

4.If display does not read within limits shown, the scale has failed and must be recalibrated.

5.If the displayed measurements fall with the acceptable limits, the scale has passed. Go to Procedure 4: Shift Test