BARTINGTON INSTRUMENTS
Page 49 of 61 OM1800/26
20.3.2. Gradiometer Data
The header is followed by the data as recorded in zigzag or parallel form. If a dual sensor
gradiometer is used then the first integer represents the left-hand sensor reading and the
second integer represents the right-hand sensor reading. The data is structured as:
Data
Value or meaning
One or two zero values
One for a single sensor, two if two sensors were used.
The gradiometer data
For a 30x 30 Grid with 4 samples/m, 2 sensors and
traverse interval of 2m there will be 3600 signed
integers in the range
±
10000. Values of 32702 in the
data are dummy values, which can be changed by the
operator as required.
One or two zero values
One for a single sensor, two if two sensors were used.
End of Data integer
32703
Three signed integers
The summary data of mean gradient, maximum
gradient and minimum gradient. For a dual sensor
gradiometer system, the values are those recorded for
the left-hand sensor.
One zero value
End of File integer
32704
Other similar files will follow for further Grids
End of Transmission integer
32705
Two-byte integer
A simple checksum formed by exclusive-or of the
current integer with the previous checksum.
21. Troubleshooting
21.1. Adjusting the Gradiometer
Instructions for correctly setting up the Grad601 Gradiometer can be found in
Checking and
Adjusting the Sensors
. See also
Care and Maintenance
for information regarding environmental
impacts on the equipment.
Some of the more common errors and fixes can be found below:
Ensure the user is magnetically clean:
Check that the user has no magnetic objects in their
pockets, clothing or shoes, and that they have no magnetic implants (e.g. surgical implants - in
doubt check with your physician). The Grad601 can be used in Scan mode to check a person
before use.
