14
Linearize mode HL
When toggled ON (default), "HL" appears on the display and
subsequent measurements are linearized.
An undesirable characteristic of replica tape is that measurements
made with analog spring micrometers are most accurate near the
middle of each grade's range and least accurate at the outer ends of
each grade's range. That is why two other grades, Coarse Minus and
X-Coarse Plus, are used to check and, if necessary, adjust
measurements at the lower and upper ends of the primary range of
20 - 115 um (0.8 - 4.5 mils).
Inside the primary range, the upper end of Coarse grade’s range and
the lower end of X-Coarse grade’s range share a 38 - 64 um
(1.5 - 2.5 mil) "overlap" region. Current Testex instructions describe a
relatively complicated and time consuming procedure (the average of
one reading using Coarse grade and one reading using X-Coarse
grade) that is used to knit the Coarse and X-Coarse sub-ranges
together to achieve reasonably accurate readings over the primary
range. This method is a compromise between accuracy and ease of
use.
When the Linearize box is NOT ticked
, the PosiTector
RTR-H
displays a height value of H comparable to the value an analog spring
micrometer would display after the 50.8 um (2 mil) of incompressible
polyester substrate has been subtracted. In other words, it is the
average of the maximum peak-to-valley distances obtained by
measuring the thickness of the replica tape without any correction.
When the Linearize box IS ticked
, the PosiTector
RTR-H
displays a
more accurate peak-to-valley height measurement HL that has been
adjusted for the non-linearity of replica tape. There is no need to
average 2 or more replicas from different grades of tape AND there is
no need to subtract the 50.8 um (2 mil) of incompressible polyester
substrate. Ensure the proper tape grade, Coarse or X-Coarse, has
been selected and appears in the upper left corner of the display.
During measurement, if the linearized measurement falls outside of the
selected tape grade's range, a more suitable tape grade will be
suggested to perform the measurement.
