Precisa 300 SCS series, Руководство по обслуживанию

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SERIES-300 S / SCS / SIP
PAG OERLIKON AG
CALIBRATION INSTRUCTIONS
D 04.09
16. Drift compensation
Description:
--> the drift of a balance is the unstability of the display value by a constant load under full capacity
All PRECISA balances are extensively checked and measured in our factory by means of robots for any
drifting. Then the mechanics of the balance are going to be adjusted until no drift compensation is
required anymore. Therefore the PRECISA balances are normally
not drift compensated.
That is why a drift compensation should be just carried out in the explicit case of any heavy mechanical
repair, such as a drop of the balance to the ground. But if ever possible any drift compensation should be
avoided.
The procedure of the drift compensation is very delicate and should be carried out extremly carefully
according to the instruction. It requires a lot of time and absolutely stable weighing condition. The balance
needs to be in absolute working temperature.
Procedure for the drift compensation:
1. Measure the drift:
1. The balance must be switched on for at least 2 houres in order to have reached working temperature
2. Place a weight of the full capacity on the top of the balance
3. After 5 minutes the difference of the display values has to be noted
4. Remove the weight
5. Wait 5 minutes and repeat the steps 2-4 three times
6. Take the average of the four noted values for the drift compensation (the difference of the four results
has to be almost the same, not more then 1-3 digits difference)
IMPORTANT:
Keep exactly on the time-table in order to find out the drift. Do not correct more digits as discribed on the
table next page according to the accuracy of the balance. If the balance is still drifting a mechanical check
is needed again. (dismantle / assemble the balance again and if necessary change the flexures).