OHAUS Pioneer PX6202M Manuel D'instruction page 25

PX Series Balance
5.2 Calibration
PX balances offer a choice of three calibration methods: Internal Calibration (for InCal models only), Span
calibration and Linearity Calibration.
Attention: Do not disturb the balance during any calibration.
5.2.1 Calibration Sub-menu (InCal models)
Note: ExCal models only have Span Calibration and Linearity Calibration.
5.2.2 Internal Calibration (not applicable to ExCal models)
Calibration is accomplished with the internal calibration mass. Internal Calibration can be performed at any time,
provided the balance has warmed up to operating temperature and is level.
With the Balance turned ON and no load on the pan, the internal calibration can be performed.
Alternatively, press the Tare / Menu-Cal button and select Internal Cal to initiate the internal calibration.
The screen shows the status, and then press any button to return to the current application after calibration.
5.2.3 Automatic Calibration (PX85 PX125D PX225D ONLY)
When Automatic Calibration is set ON, the balance performs a self calibration:
• when it senses a temperature change of 1.5°C
• or every 3 hours
AutoCal will automatically calibrate the Balance (using the internal mass) each time there is a change in
temperature significant enough to affect accuracy.
5.2.4 InCal Adjust (not applicable to ExCal models)
Use this calibration method to fine tune the effect of the Internal Calibration.
Calibration Adjust may be used to adjust the result of the Internal Calibration by +100 divisions.
Note: Before making a calibration adjustment, perform an Internal Calibration. To verify whether an adjustment is
needed, place a test mass equal to the span calibration value on the pan and note the difference (in divisions)
between the nominal mass value and the actual balance reading. If the difference is within +/- division, calibration
adjustment is not required. If the difference exceeds +/-1 division, calibration adjustment is recommended.
Example:
To perform a Calibration Adjustment, select InCal Adjustment from the list of Calibration Menu; enter the value
(positive or negative divisions) to match the difference noted earlier in the procedure.
Recalibrate using Internal Calibration. After calibration, place the test mass on the pan and verify that the mass
value now matches the displayed value. If not, repeat the procedure until Internal Calibration reading agrees with
the test mass.
Once completed, the balance stores the Adjustment value and the display returns to the current application.
5.2.5 Span Calibration
Span calibration uses two calibration points, one at zero load and the other at specified full load (span). For
detailed calibration mass information, please see the specification tables in section 9.1.
With the balance turned ON and no load on the pan, Span Calibration can be performed. The best accuracy is
achieved using the mass closest to the full span value.
Expected weight reading:
Actual weight reading:
Difference in gram:
Difference in division:
200.000 (Test mass value)
200.014
– 0.014
– 14 (InCal Adjust value)
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