Adjusting The Zero Point Offset Value; Off-Center Load; Checking The Off-Center Load - Sartorius Portable Series Service Manual

Adjusting the Zero Point Offset Value

- Afterwards, check the zero point offset value again (see page 17).
- Now you can make additional fine adjustments of the zero point offset value by using parallel resistor R131.
- Perform the same procedure as above, only this time, connect the resistor decade box parallel to resistor R130,
which has already been soldered to the main PCB, and solder the resistor as determined by using the table to
position R131 of the main PCB (118).
- After you have adjusted the zero point offset value, close the balance/scale housing.

Off-Center Load

Checking the Off-Center Load

- Compare the values displayed with the tolerance ranges given in the following table.
18
- Open the balance/scale housing (see page 14).
- Locate the position of balancing resistors R130 and R131 on the main PCB
(118) (see „Overview of the Test Points" on page 31).
- Desolder balancing resistors R130 and R131.
- Connect a resistor decade box to the main PCB (118) in place f resistor
R130.
- Adjust the largest resistance possible on the decade box.
- Reconnect the balance/scale to AC power.
- Access the gross value mode (see page 15).
- Change the setting on the resistor decade box until the gross value
displayed corresponds approximately to the set value.
- Read off the resistance indicated on the decade box, and locate the next
higher resistance from the E12 standard.
Example: 7.515 kOhm (decade box) yields 8.2 kOhm (resistance)
- Unplug the balance/scale from AC power, and disconnect the resistor
decade box.
- Solder the resistor as determined with the use of the table to position R130
of the main PCB (118).
- Turn on the balance/scale by pressing the
- Place the off-center load test weight on position 1 on the weighing pan
(101).
- Tare the balance/scale by pressing the
- Place the test weight on positions 2 through 5 (in sequence), and write
down the values displayed:
Example (PT6-000V1):
key.
control.
T
Pos. 1
T
Pos. 2
Pos. 3
Pos. 4
Pos. 5
0.0 g
+ 0.2 g
+ 0.3 g
– 0.1 g
– 0.2 g