OHAUS 3000 Series T31P, Service Manual

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CHAPTER 1
GETTING STARTED
1.8 SCALE SETUP & CALIBRATION
Two calibration processes are available: Span Calibration and Linearity Calibration.
Preliminary Steps :
1. Be sure appropriate calibration masses are available before beginning calibration.
2. Be sure the scale base is level and stable during the entire calibration process.
3. If LFT is set to On, calibration is unavailable.
To set LFT to OFF, see Section 1.10, page 1-13.
Note: To use the LFT mode again after turning it off, it is necessary to have the
Indicator locked and sealed by local Weights and Measures authorities.
4. If the Calibration Menu is locked in the Menu Lock submenu, turn it back on:
– Press and hold TARE/Menu until C.A.L. appears, then press No .
– SETUP appears. Press No . READOUT appears. Press No .
– MODE appears. Press No . UNIT appears. Press No .
– PRINT appears. Press No .
– MENU LOCK appears. Press Yes . RESET appears. Press No .
– CALIBRATE appears. Press Yes . Then press No continuously until End appears.
– Press Yes twice to exit menu mode.
5. Allow the Indicator to warm up for approximately five minutes after stabilizing to room
temperature.
6. To abort calibration, press the Exit button anytime during the calibration process.
1.8.1 Geographical Adjustment Factor
The Geographical Adjustment Factor (GEO) is used to compensate for variations in gravity.
Local gravity variance (depending on distance from the equator and altitude above sea level) is
compensated for by entering a Geocode (conversion factor). See Appendix B to determine the
Geocode conversion factor that corresponds to your location.
Note: Changing the GEO Factor alters the calibration. The GEO value was set at the factory
and should only be changed if the location of use varies from the default setting.
To adjust the GEO Factor, press and hold TARE/Menu until C.A.L. appears. Press Yes .
SPAN appears. Press No . Linearity appears. Press No . GEO appears. Press Yes. The
default GEO setting appears. Press No to increment the number, or Back to decrement, until
the desired number appears. Then press Yes .
GEO appears again. Press No to exit the GEO menu. End appears. Press Yes to return to
the CAL menu. Press No continuously until E.n.d appears. Press Yes to return to weighing
mode.
3000 Series T31 Indicator Service Manual 1-9 Ohaus Corporation www.ohaus.com