ACU-RITE 200S - Manual (Page 74)

60 II
II - 1 Installation Set
u
p Linear Error Compensation
Linear error compensation can be applied, if the results of the
comparison with a reference standard show a linear deviation over the
whole measuring length. In this case the error can be compensated by
the calculation of a single correction factor.
To calculate the linear error compensation use this formula:
Correction factor LEC = ((S – M) / M) x 10
6
ppm with:
Example:
If the length of the standard you used is 500 mm, and the measured
length along the X-axis is 499.95, then the LEC for the X-axis is
100 parts per million (ppm).
LEC = ((500 – 499.95) / 499.95) x 10
6
ppm = 100 ppm (rounded to
the nearest whole number).
8 Once determined, the encoder’s error information is entered
directly. Press the TYPE soft key to select LINEAR compensation.
8 Enter the compensation factor in parts per million (ppm), and press
the ENTER key.
Non-Linear Error Compensation
Non-linear error compensation should be applied if the results of the
comparison with a reference standard show an alternating, or
oscillating deviation. The required correction values are calculated, and
entered in a table. The 200S supports up to 200 points per axis. The
error value between two entered adjacent correction points is
calculated with linear interpolation.
S measured length with reference standard
M measured length with device at axis
Non-linear error compensation is only available on scales
with reference marks. If non-linear error compensation has
been defined, no error compensation will be applied until
the reference marks have been crossed.