Accusetter Manual - BC MacDonald & Co.

Gaging Formulas
The gaging formula under FUNCTION on the Accusetter II allows the user to add,
subtract, multiply, or divide inputs from transducers A, B, C, and D. The Accusetter II
requires a gaging formula for all applications programmed in the Multiple Check and
Multiple Fixture programs.
For air gaging applications, the gaging formula will always be 1.000 for Input A or Input B.
For electronic gaging applications using LVDTs, the gaging formula will be dependent
upon the specific gaging application.
Gaging probes used within any system are strategically mounted to contact the work piece
at specified locations to perform measurements. These probes, or their output values, must
be combined in an algebraic fashion to provide the measurements desired.
There are four elements required to developing a gaging formula. These include:
1. Input definition.
2. Polarity.
3. Multiplier.
4. Gaging Function.
Input definition is simply identifying the probes or “inputs” to the readout that will be used
to measure the part. As an example, let us use two opposing LVDT probes and assume that
these are the first inputs connected to the readout. These will be identified as inputs 1A and
1B.
Polarity must be determined for the application at hand. For example, consider a gage with
two probes measuring an outer diameter, the probe’s normal operation defines the polarity
as (+) when the tip is depressed. Thus the polarity programmed in the Accusetter for each
of our inputs for this example will be (+) plus. As the diameter grows, the probes are
depressed providing positive readings indicating a larger part diameter.
Next, we must apply a multiplier to the probes outputs that is dependant on the application.
The multiplier is determined by the number of probes used to perform the measurement or
to correct any ratio that may be introduced by any contact arms or tooling.
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