Methods Of Measurement; Data Reduction - HBM MP85A Operating Manual

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6

Methods of measurement

A measurement start/stop can be implemented manually with the PME
Assistant in individual operation, externally via a digital input or via the field
bus interfaces.
When measurement starts, the measured quantities acquired by the sensors
are written as an x/y value pairs with a time stamp to the internal MP85A
process controller memory and rated as OK or NOK by means of defined
windows, an envelope curve or a tolerance band. In addition, limit value
monitoring can be included in the evaluation. The last measurement curve in
each case can also be instantly plotted and displayed. All processes can be
stored in the background, independently of this display.

6.1 Data reduction

y=f(x)
A measurand Y (force) is recorded and rated as a function of a measurand x
(displacement). The measurement points are also given a time stamp.
Advantage: Intelligent data reduction. Curve points are only generated when
there is a sufficiently large change to x or y. The values nx and ny are user-
selectable.
Fig. 6.1: Force/displacement-driven process curve determination
y=f(t)
A measurand on channel y is recorded as a function of time.
Advantage: There is no need for the X sensor (the displacement sensor on a
press, for example).
Condition: Reproducible feedrates, as otherwise the curve that depends on
them would be shortened or lengthened.
HBM
MP85A process controller
A2392−5.0 en