LabChart contains a default calibration for the FE117 BP Amp when used with the included MLT0670 Pressure Transducer. This means after connecting a BP Amp to a PC via a suitable PowerLab, the data in the LabChart channel will be calibrated to units of mmHg automatically. This calibration information is shown in the Units Conversion dialogue. ADInstruments has always recommended users go through a manual calibration process to replace this default Units Conversion and ensure the most accurate results.
From the introduction of the BP Amp until LabChart 8.1.11 the default calibration data within LabChart has remained unchanged. However, it has come to light that this data is no longer accurate for transducers that are currently shipping. An error of 5-10% is present when using the default calibration.
LabChart 8.1.12 contains updated calibration data which brings the error back within the 2% quoted in the FE117 specifications. ADInstruments still recommends going through a manual calibration procedure to take into account any individual variance between transducers and ensure the most accurate data.
Note: Opening an existing file (settings or data) in LabChart 8.1.12 will have no effect on the calibration of channels within that document. This applies to both data already recorded within the file as well as any new data that is recorded. It also applies whether a manual calibration was completed or the default calibration was used. Only new files created in LabChart 8.1.12 or above will use the new default calibration data.