|
SURFACE
ACCURACY DIN 876
DESIGN
FEATURES
The
bottom side of the measuring surface has to be provided
with at least three support points. The design of the
plate will be such as to allow the forces acting on
the table to be directed towards the support points
in order to minimize distortion.
|
SURFACE QUALITIES |
| DIN
876/III |
planed
/ milled |
| DIN
876/II |
fine
planed / milled, alternatively scraped |
| DIN
876/I |
fine
milled, alternatively fine scraped |
| DIN
876/0 |
fine
scraped with bluing |
FLATNESS
Measured
at standard temperature of 20° C (68° F). Allowable
variation of the measuring surface to a true plane in
microns (µ) or mil = 0.001 inch where L is the
length of the longest side of the plate.
|
Metric
(L in mm) |
SAE
(L in inch) |
| DIN
876/III |
µm
= 40 + (L / 25) |
mil = 1.575 + (L / 25) |
| DIN
876/ II |
µm
= 20 + (L / 50) |
mil
= 0.787 + (L / 50) |
| DIN
876/ I |
µm
= 10 + (L / 100) |
mil
= 0.394 + (L / 100) |
| DIN
876/ 0 |
µm
= 4 + (L / 250) |
mil
= 0.157 + (L / 250) |
|
