Loads an F/T transducer calibration file.
In: Path to the calibration (*.cal) file for the transducer you are using. Calibration files are named like 'FTxxxx.cal', where 'xxxx' is the serial number printed on your transducer or it's power-supply box.
In: The calibration within the file to use. Should be 1 if there is only one calibration in the file (Most .cal files have only one calibration in them).
0 if successful, nonzero if not successful.
Resets the output units to whatever the calibration file specifies. If the hardware acquisition task is currently running, make sure to restart it (i.e. via StartSingleSampleAcquisition) before attempting to read f/t values. Otherwise, the temperature compensation, voltage range, etc. may not be correct for the system you are using.