HP 5528A User Manual

Model 5528A
Straightness Mea s urcment s
3. Air turbulence.
A
Straightness meas uremcnt is especia ll y s us ce ptible to environmemal effects. It is imposs ible to
quantitati ve ly determine how these environmental charact eristiCS wil l affect thc me as urement,
although it is someti mes poss ible to identif y when they are ha v ing an effect.
Ex cess ive vi bration and/ or air turbulence can be identified by -
1.
Random drifting of the measurement results when the Optic s arc al rest.
2. Drifting in creasing as the distance between the Optics in crea ses.
The effects of vibrati on ciln be further identified if the dr i fting of the mea su rement stops when
the ma chine is turned off, or by exceeding the s lew rate during thc measurement ( disruptins the
measurement ).
Minimizing Effects
1. Thermal expansion of the machine or Optics.
These effects can be minimized by l elling the machine and Opti cs reach therm al equilibrium
before making a mea surement.
2. Machine Vibration s.
a. Adequate fixluring is the main way to reduce the effects of vibration.
Make sure the Straightness Reflector's Base is sec ur ely fastened to the table, and thallhe
P os t is sec urely fa stened to the base on one end and the Reflector on the other.
Avoid long
ex tensions.
b. Vibrational effects can also be reduced by -
•
Averaging su ccess ive runs or averasing successive averages.
• More accurate manual sl ope removal.
• Reduced feed rate s.
• Pad s under the reflector 's ba se as a lasl re so rt in high-vibration, low -accuracy work.
3. Air Turbulence
Air
IUrbulence is caused by temperature differen ces in the air. To remov e th ese differen ces,
you s
hould remo ve their so ur ces (e.g., open door s, lamps, exhau st fans, motor s, etc.),
Alternatively, yo u s hould mix Ihe air thoroughl y along the meas urement p at h, u si ng a large
fan. If you c an reduce the so ur ces of temperature differen ces and mix the measurement path
air, yo u'll be even better off.
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HP 5528A Specifications

General

Brand	HP
Model	5528A
Category	Measuring Instruments
Language	English