Alldaq ADQ-250 cPCI, Руководство пользователя

Страница: 12 / 38

12 Initial operation
Initial operation Manual ADQ-250 series Rev. 0.9
2.5 Balancing/Calibration
By the ALLDAQ-Manager you can select which balancing data record (factory or user balancing)
should be activated when booting the computer. You can change the setting via the ALLDAQ-
Manager.
2.5.1 Factory balancing
The ADQ-250 series will be balanced before delivery. The balancing data will be stored into an
EEPROM. If a re-balancing should be neccessary please contact our service department. For
contact details see chapter 4.4 on page 33.
2.5.2 User balancing
For a precise voltage measurement considering multiple error factors, e. g. caused by the field
wiring you can balance the analog inputs by yourself. After balancing the application-specific
balancing data can be stored beside the factory balancing data into an EEPROM.
Please follow the procedure below:
1. Power-on the system with the ADQ-250 series.
2. Connect the part of the field wiring you want to include into the balancing.
3. Apply a constant voltage and monitor the voltage by a high-precision voltmeter (e. g.
multimeter). Make sure, that the voltmeter has a higher accuracy than the respective board
of the ADQ-250 series.
4. Run the balancing tool in the ALLDAQ-Manager and follow the procedure in the appropria-
te help file. See also chapter 2.4 on page 11.
Note : Repeat the balancing for each channel separately.
TIP:
To achieve the best accuracy, we recommend to set that sample rate in the balancing tool
which one you want to use in your measurement later.
Figure 3: Wiring for balancing