HP 5528A User Manual

Model 5526A
Straightness Mea s urement s
11-
24
In orde r to get the correct spacing between the Turning Mirror and the Refl ec tor for a Straightness
measurement al ong a vertical axis, y ou must assemble the Reflector In it s mount with the sloned
opening away from the screws labelled ", " in Fi gure 11·2. B ec ause of this. the Reftector ca n't be
rotated around the junction of its mirrors to provide a measurement with its mirrors rotatcd 180
degrees.
Misalignment Between Machine Travel and the Laser Measurement
Axis (Slope)
Description
Thi s does not cause a cosine error, as it did in Di s tan ce measurement s. In stead. mi sa lignment causes
a slope to be measured, since the straightness reflector is not directing it s reference bisector along a
path
parallel to the axis of travel. (Sec Fi gure 10-12 .)
Minimizing Effects
The three ways 10 removc s lope from the Straightness data are -
1. Automatic
Calculator reduction and plot of data.
2. Manual mathematic reduction and plot of data.
3. Manually aligning th e slope out with a zero-end-point-fi!.
Manual alignment may be nece ssary if the sl ope becomes great enough 10 reset the
Measurement Di spl ay before the end of travel is reached, or if a s ub se quent squarencss
measur ement is to be made .
If you have the HP Dimensional Metrolog y Anal ys i5 System ( DMAS ), you will want to use method
"1" above. and automatically remove s lope . If you don 't have the DMA S, you wi ll ha ve to use
method 2 or me thod 3,
Method 2 is done by calculating either a 7.e ro-end· point or a least -s quares be st line fit through
the data points, ar,d subtracting the s lope at each co mmand position, Section 21 describes how 10
do this.
Method 3 is described in detail in thc " I NSTALLAT ION AND ALIGNMENT OF OPTICS" parI of
thiS User's Guide Section,
Environmental Errors
Description
As with any accurate measur emen t, and in particular with all la ser System mcasurements, the
environmen t pla ys a very imporlant role,
En
vironme ntal errors co me from -
1, Thermal expansion of the ma chine or pari.
2, Machine vibration,

HP 5528A Specifications

General

Brand	HP
Model	5528A
Category	Measuring Instruments
Language	English