Sensor Qc Features; Static Function Test (Sft) - Geometrics MetalMapper 2x2 Operation Manual

5. Sensor QC Features

5.1 Static Function Test (SFT)

Before starting data acquisition, a Static Function Test (SFT) must be performed and the results
verified to ensure proper data collection. The SFT should be performed in an area without
known metallic objects nearby. The SFT directly compares the amplitudes of the measured
data to a known reference measurement. This known reference measurement is performed at
the factory under controlled conditions and represents the ideal instrument response. This
measurement is stored in the master SFT file which is used as the comparison. The master SFT
is stored on the computer in the directory:
/var/lib/MetalMapperII/InstrumentFunctionTest/
With the naming convention:
<FunctionTest>_<CartSerialNumber>_<SFT>_<ISOSerialNumber>_<YYYYDDD>_00.h5
Where <CartSerialNumber> is the Serial Number printed on the outside of the sensor platform
and referenced in the application.properties file and <ISOSerialNumber> is the serial number
printed on the ISO unit.
The "Time Window for QC" setting in the QC tab displays the time gates for the collected
measurements that will be compared to the known reference measurement. The default
values for this gate are 104, 302 microseconds and cannot be changed. These time gates match
the time gates used in most SFT processing workflows in the data processing software. The
acquisition software will automatically compare the amplitude of the signals on each channel
within the selected time gates. If the measured amplitudes are within 20% of known reference
amplitudes for each channel, the instrument will pass the function test. Values greater than
20% difference will cause the sensor function test to fail.
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