Calibrating the Scale
This section provides procedures in calibrating the scale and programming its parameters. These procedures are applicable to NCR 7895 scanner/scale units only.
Only certified personnel can perform the scale calibration procedure and place the scale into service for trade to comply with governmental weights and measures regulations.
The NCR 7895 must meet the following accuracy requirements.
- The NCR 7895 is considered a new unit each time the scale is calibrated. This status lasts for thirty (30) days.
- The NCR 7895 is considered an in-service unit thirty (30) days after the scale is calibrated.
| Weight | New Unit | In Service Unit |
|---|---|---|
| Up to 2.500 kg | ± 0.000 kg | ± 0.005 kg |
| Above 2.500 kg | ± 0.005 kg | ± 0.010 kg |
| Up to 5.000 lb | ± 0.000 lb | ± 0.010 lb |
| Above 5.000 lb | ± 0.010 lb | ± 0.020 lb |
During factory testing, the scale is calibrated one or more times to test the scale calibrating function. This calibration test is not sufficient to make the scale ready for weighing in trade. The scale MUST be calibrated following installation in their working environment to offset effects of local gravitation, imperfect leveling, and working environmental conditions. The scale MUST be calibrated when any of the following occur (this is a government requirement).
- Initial installation of an NCR 7895
- When the scale cannot be zeroed
- When the diagnostics indicate a calibration error
- When the Scale Assembly is replaced or serviced
Scale capacity is 15 ±0.005 kg or 30 ±0.01 lb. Also, the scale weighs in increments of ±0.005 kg or ±0.01 lb.
One or more certified weight sets are required to calibrate and certify the scale. The following are examples:
- Whole Pound Weight Set: NCR Part Number 998-0633009
- Fractional Pound Weight Set: NCR Part Number 998-0633012
- Kilogram Weight Set: Obtain locally
Refer to the following required weights depending on the unit of weight configured for the scanner.
| Unit of weight | Required calibration weight |
|---|---|
| Pound | 30 lb (25 lb for calibration and 30 lb for testing) |
| Kilogram | 15 kg (10 kg for calibration and 15 kg for testing) |
It is recommended to exercise the scale from zero up to its full capacity (30 lb for US scales and 15 kg for metric scales) at least three times before entering calibration. This is done by placing and removing the scale weights box on the Top Plate three times.
Complete each calibration step within 30 seconds. Otherwise, the calibration process automatically ends. At any time during the calibration process, if the units of measure are modified (for example, from lb to kg) and a 30‑second time is completed, the Scale Display flashes CAL and the 7‑segment display shows the U14 warning code. Both codes indicate that the scale is out of calibration.
