OHAUS PR124 User Manual

OHAUS PR124 User Manual Manual pdf 16 page image

EN-14 PR Series Balance5.2 CalibrationPR balances offer a choice of three calibration methods: Internal Calibration (for InCal models only), Spancalibration 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, press the Tare / Menu-Cal button and select InCal to initiatethe internal calibration.The screen shows the status, and then press any button to return to the current application after calibration.5.2.3 Cal 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 isneeded, 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, calibrationadjustment is not required. If the difference exceeds +/-1 division, calibration adjustment is recommended.Example:Expected weight reading: 200.000g (Test mass value)Actual weight reading: 200.014gDifference in grams: – 0.014gDifference in divisions: – 14 (InCal Adjust value)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 massvalue now matches the displayed value. If not, repeat the procedure until Internal Calibration reading agrees withthe test mass.5.2.4 Span CalibrationSpan calibration uses two calibration points, one at zero load and the other at specified full load (span). Fordetailed calibration mass information please refer to the specification tables in the "Span Calibration Points",SPECIFICATIONS, Section 9.With the balance turned On and no load on the pan, Span Calibration can be performed. The best accuracy isachieved using the mass closest to the full span value.Steps for span calibration1. Press and hold the Tare / Menu-Cal button, and theCalibration Menu will display.