7.2 How to calibrate the module?
Acqiris SA230E User's Manual
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7.2 How to calibrate the module?
Calibration principle
The module is initialized without calibration.
A calibration is mandatory before making any acquisition to guarantee measurement accuracy. The
MD3 driver prevents an acquisition from being performed unless a self-calibration has first been
completed.
Since a full internal calibration of an ADC module can be time consuming because of the many
possible configuration states, the self-calibration is performed only for the current configuration state.
A new self-calibration is required after every change of configuration of the module.
See
section.
Running fast calibration
The function
SelfCalibrate
should be used to perform a fast calibration.
As explained above, a calibration is required after every acquisition parameter modification (e. g. full
scale range, filter, sample rate, ...). The
IAqMD3Calibration.IsRequired
IVI.NET property or
the
AQMD3_ATTR_CALIBRATION_IS_REQUIRED
IVI-C attribute can be used to check if a new
self calibration is required .
MD3 Smart-calibration
The smart calibration implemented in MD3 drivers allows to save time by automatically keeping in
memory the calibration information from any self-calibration performed since the beginning of the
session. When the acquisition parameters are changed, no re-calibration of the module is necessary if
a self-calibration has already been performed with the same acquisition conditions (i.e. the same set of
parameters), unless the clock mode parameters are changed.
Indeed, any change in the clock mode parameters (i.e.
External clock frequency
or
Reference
mode
parameters), induces a restart of the clocks which requires a new self-calibration.
Calibration optimized for a target voltage
It is possible to optimize the calibration for a specified target voltage. In this case, the self-calibration
will minimize the noise level at the channel input value equal to this specified target voltage.
When setting to true the
Calibration.TargetVoltageEnabled
property , the self-calibration
will minimize the noise level at the channel input value equal to
Channel.CalibrationTargetVoltage
. Note that when set to true, the
Channel.Offset
value is taken into account in the self-calibration, and therefore changing the
Channel.CalibrationTargetVoltage
value, or changing the
Channel.Offset
, will require a
new self-calibration.
