Counts are to be recorded on a data sheet that provides,
as a minimum,
spaces on which to record the counts for each field,
filter identification number,
analyst’s name, date, total fibers counted, total fields counted, average count, fiber density, and commentary.
Average count is calculated by dividing the total fiber count by the number of fields observed.
Fiber density (fibers/mm²) is defined as the average count (fibers/field) divided by the field (graticule) area (mm²/field).