HEIDENHAIN NPD 281 v.3 - Manual (Page 9)

9
Series of measurements: The MIN, MAX and DIFF values of an uneven
surface
Example: Series of measurements for determining eccentricity e
Finding Minimum and Maximum Values
2e = r
MAX
Ð r
MIN
e = DIFF
2
r M
AX
r M
IN e
DIFF
MAX
MIN
ACTL
Finding Minimum and Maximum Values From a
Series of Measurements
After a series of measurements has been started, the display
transfers the first measured value to the memory for minimum
and maximum values. Every 0.55 ms, the display compares
the current measured value with the memory contents: A new
value is stored if it is greater than the stored maximum value
or smaller than the stored minimum value. At the same time,
the display calculates and stores the difference DIFF between
the current MIN and MAX values.
Display Meaning
MIN Minimum value from the series of measurements
MAX Maximum value from the series of measurements
DIFF Difference MAX – MIN
ACTL Current measured value
Starting the series of measurements and selecting
the display
You can start the series of measurements either by pressing
MOD and selecting the desired display — as described on the
following pages — or by external signal over the switching
inputs at the D-sub connection EXT (X41, see page 34).
When a series of measurements is started, the internal MIN/
MAX/DIFF memory is reset.