User`s manual

Accurate Technology ProScale Page 8 of 48
ProScale Terminology
All ProScale M150 and M250 systems consist of a SCALE, a READHEAD,
(or encoder) and a DISPLAY (digital readout).
The SCALE consists of a series of conductive patterns bonded to an
aluminum extrusion. The Model 150 Scale is .765 inches (19mm) wide and
comes in standard lengths of 14.25 inches (362mm) and 22.25 inches
(565mm) to measure 10 inches (250mm) and 18 inches (450mm)
respectively.
The Model 250 Scale is 2.02 inches (51mm) wide and comes in several
standard lengths from 16 inches (406mm) to 244 inches (6.2m) to measure
from 12 inches (300mm) to 20 feet (6m) respectively.
NOTE: All ProScale Scales are approximately 4 inches (100mm) longer in
physical length than in their specified measuring capability.
The READHEAD, (sometimes called ENCODER) contains a computer chip
which transmits and receives signals to and from the Scale using capacitive
coupling. The received signal is used by the ReadHead to calculate its
position to within 10 microns (10µm or .0004in). This position data is then
sent to the DISPLAY, where it can be displayed in millimeters, centimeters,
inches, or fractions and sent to an external data acquisition device via the
Display’s SPC output, or wirelessly via RF.
Multiple READHEADs (connected to individual DISPLAYs or data acquisition
units) may be used on the same SCALE simultaneously.
Scales
Absolute
Absolute, (often referred to as ABS) systems use a robust and sophisticated
method to measure position, resulting in a high immunity to electrical
interference and one that does not forget its position when power is removed.
An ABS system measures its actual position by reading a pattern which is
unique at any given location over a segment length. The maximum length of
a ProScale absolute segment is 430.08mm (16.933 in.). The segment must
then repeat.
Consider the illustration above to represent a ProScale approximately 50
inches long. There are three absolute segments joined together. Within