The accuracy of
a measurement system is the degree of closeness of measurements of some
quantity to its actual (or true) value.
The precision of a measurement system, also called reproducibility or
repeatability, is the degree to which repeated measurements under
unchanged conditions show the same result. (©
Our Capacitive Absolute encoder technology (ABS) has been
in production since 1997. Absolute Technology
measures the actual sensor position by reading a pattern which is unique
at any given location over its length (approximately 17 inches). This results in a measuring
system with a high immunity to loss of position due to motor electrical
noise, power transients, or magnetic fields.
There is no position loss
when the digital readout is turned off, or when power is interrupted.
ABS technology is still used in many of our products.
Inductive Series II Technology
Our Inductive Series II Incremental measuring technology began production in
June 2013. This technology, and the systems manufactured using it, are
direct (mechanical) replacements for earlier Series I systems. Series
is more robust technology than Series I. Its signal is more immune to
power transients, magnetic fields, and ESD. Plus, the slew (movement
rate) is greatly increased. Series II technology is used in ProScale Models
190, 290, 390 and 590 as well as many of
the turn-key measuring systems we manufacture incorporating these models.
Inductive Series I Technology
Our Inductive Series I Incremental measuring technology
in production since the 2007. Inductive measuring technology
measures the distance it has traveled relative to a starting point. It
is however a much more robust technology than the Capacitive Incremental
technology we used previous to 2007. Its signal is more immune to
EMI, power transients, magnetic fields, static, so the
position information is not lost as easily as the older technology.
Inductive Series I production ended in June 2013.
using this technology are no longer manufactured.
Capacitive Incremental Technology
Our Capacitive Incremental measuring technology
in use since 1989. Incremental technology
measures the distance it has traveled relative to a starting point. As
long as the signal is not reset or interrupted (by removal of batteries,
EMI, power transients, magnetic fields, static, etc.), the
position information is not lost. Incremental technology was used in all of
the measuring systems we manufactured until 1997. We began to phase out
this technology in favor or more advanced Inductive Technology in 2007, and production
was ended in 2009. Products
using this technology are no longer available.
An absolute measurement is the distance from some fixed position. On a table
saw, this is typically the distance from the right edge of table saw blade.
For the best accuracy, this is the distance from the right edge of the
running blade - accounting for any variance of blade flatness, or
bearing run-out. The absolute distance can be set to zero, or to any
other offset, quickly and easily using the readout keypad. The
absolute distance is retained when the readout is turned off or switched
into INCremental measuring mode.
An incremental measurement is the distance from a
current (absolute) position. On a
table saw, this could be the distance between dados or grooves. It
could also be the distance from the left edge of the saw blade. The incremental distance can be set to zero,
or to any other offset,
quickly and easily using the readout keypad. Changing between Absolute and
Incremental modes is easily done by pressing a single key. The
incremental distance is retained when the readouts power is off.
Statistical Process Control is
a tool that businesses and industries use to achieve quality in their
products and/or services.
By monitoring the accuracy, or in-tolerance percentage of manufactured
products, and collecting current measurement data from measuring devices, a
company can adjust their processes and machines to produce better products,
Most of our measuring products may be integrated into a company's SPC
program by use of serial connection to a computer or printer.
This serial connection uses the format called Mitutoyo Digimatic®
for the transmission of measured values or positions. Our encoders carry
this signal to our digital readouts. Many of our
digital readouts also have a 10-pin output connector which can be used
to transmit the currently displayed reading.
These signals may be gathered using
or transmitted wirelessly using our
directive aims to restrict certain dangerous substances used in electronic
equipment. Any RoHS compliant component is tested for the presence of Lead (Pb).
There must be no more than 0.1%. And, any RoHS compliant component must have
100 ppm or less of mercury.
is a condition that may not be visible to the human eye, but will affect
linear measurements. Be sure to take precautions when installing ProScale in
order to eliminate the possibility for Abbe error.
Abbe error refers
to a linear error caused by the combination of an angular error and a
dimensional offset between the sample and the measuring system. It is
important to understand that the information the encoder is providing is
only the position of the Encoder on the scale. To illustrate this, see
the figure, which shows a linear measuring device. (The apparent distortion
in the measuring device is intentional - for this example - to show the
measuring device with a curvature in its mounting.)
Suppose the curvature in the figure is sufficient to produce an angle of 40
arc-seconds. If the measuring device moves 10 inches, the probe will be
found to have moved 10.0039 inches, resulting in an error of +0.0039
inches. Abbe error could be lessened by moving the measuring system closer
to the sample. This effectively solves one half of the Abbe error problem
(offset) and leaves only the angular mounting problem to be solved. Angular
error can best be countered through proper design and placement of the
linear scale. Sources of angular error include:
Mounting the linear scale to an
imperfectly flat surface.
Mounting the linear scale to an
imperfectly straight surface.
Curvature of ways (or linear
bearings) used to measure the sample.
Contaminants between the probe
and item being measured.
Friction in any part(s) of the