A field sample is a measurement taken from the process that has the calculated average of 10 consequent measurements. A field sample is usually taken when a snapshot of the process condition is needed.
To take a field sample, browse to the Diagnostics view and select Field sample.
The result of the field sample is displayed on the screen, with date, time and measurement results. The results can be used to calculate corrections against a laboratory or other reference if needed: For example, if the raw concentration (the measurement value without field correction) indicates a value of 10.0, and laboratory reference indicates a value of 9.0, the required field offset would be -1.0 to make the refractometer reading to match the laboratory.