Precision glass linear scale
5 - 10 µm
RSF Elektronik
selected floatglass, scribed and broken
planarity 10 µm/100 x 100 mm
coefficient of expansion 9 µm/°C/m
glass thickness for scale 2,0 +0/-0,2 mm
glass thickness for mask 1,0 ±0,1 mm
max. length of glass 3300 mm
outbreaks on edges < 0,1 mm
Graduation:
sputtered chrome on glass
transmission 60% at 400 - 900 nm
gratings 10 : 10 µm, 20 : 20 µm
line width ratio 1 : 1
max. line tolerance ±10%
graduation accuracy < ±3 µm per 1000 mm
parallelism graduation to glass edge < 0,3 mm per 1000 mm
max. track length 3150 mm
Acceptable defects in the graduation/reference mark area:
pinholes < dia Ø 250 µm or several smaller defects whose total area does not exceed this
dots < dia Ø 180 µm or several smaller defects whose total area does not exceed this
defects visible to the naked eye on the illuminated table are not critical
max. 3 defects per 1000 mm
minimum distance between two defects 40 mm
Acceptable defects in the surrounding area:
dots < Ø 0,3 mm
max. 6 defects per 1000 mm
On request:
other glass types
other glass thicknesses
other coatings
sliding coat on mask
other gratings
