Zero-Point Offset Value; Adjusting The Zero-Point Offset Value - Sartorius Talent Series Service Manual

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Zero-point Offset Value

The zero-point offset value adjustment is necessary for adapting the bridge
voltage of the strain-gauge load receptor to the operating range of the
balance/scale electronics. This may be necessary:
– after replacing the strain-gauge system
– after replacing the main PCB
– if the span cannot be adjusted (even with the service software) and the error
code „E 02" is displayed
– when the zero-point offset voltage has changed and is outside the tolerance
limit (e.g., due to the strain gauge load receptor being „bent")

Adjusting the Zero-point Offset Value

– Open the balance/scale (see page 48)
– Connect the cable from the digital voltmeter (DVM) to IC15, pin 6 and
ground
– Place the shock absorber and the weighing pan/load plate on the balance/
scale and reconnect the power supply
– Use the DVM to test the preload voltage with no load on the balance/scale
Target (mV)
- 0.25 to - 0.49
– If the zero-point offset voltage is outside the tolerance range listed above,
balancing resistor R29 must be adjusted in accordance with the table below.
A/D converter output (%)
4.3% to 8.3%