Double-Beam Plane-Mirror Interferometer
SP-DS Series
Design and Operation Double-beam plane-mirror interferometers of the SP-DS series allow a wide variety of applications as OEM measuring systems or standalone units. Two parallel measuring beams are used to acquire two length values independently of each other and with maximal resolution and precision. Difference values or angle values may be calculated from this and the factory-calibrated beam spacing. The single-beam measuring principle applied to every measuring beam allows measuring set-ups in compliance with the Abbé princple which avoids first-order measurement errors.
Major Performance Features
• Simultaneous length and angle measurement or differential measurement with maximal accuracy
• Easy adjustment and handling using an alignment base
• HeNe laser provids a light source with a high frequency stability
• Fiber coupling of laser light
• Correction of environmental influences
• Selectable materials of sensor head: aluminium, stainless steel or Invar
• Measurement software as well as support for OEM software for Windows and Linux
Operating Principle
Applications
• OEM measuring system for laser-interferometric precision length measurement and calibration of coordinate and length measuring machines, machine tools, measuring and positioning tables
• Differential measurement, e.g. materials testing, dilatometry or deflection and creep behaviour investigations • Simultaneous length and angle measurements of positioning stages or for machine calibration
Technical Data
Model SP 120 DS Model SP 2000 DS Length measuring range
mm
70
2000
Resolution
nm
0.1
0.1
Laser wavelength
nm
632.8
632.8
Frequency stability of the HeNe laser (after warm-up period)
≤ 3 ∙ 10-7
≤ 2 ∙ 10-8
Warm-up period of the HeNe laser
min
1
10...20
Beam separation (standard)
mm
4 / 12.5 / 25.4
Angular measuring range
arcmin
±1.5
Angular resolution at 0.1 nm length resolution
Beam separation: 4 mm
Beam separation: 12.5 mm
Beam separation: 25.4 mm
arcsec
arcsec
arcsec
0.005
0.002
0.001
Operating temperature range
°C
15...30
Maximum moving mirror translation rate
mm/s
800
Interfaces standard
optional
RS232C, USB
Digital 32-bit parallel interface Digital
incremental signals (TTL level)
Analog incremental signals (1VPP)
Size [L x W x H] / mass of sensor head with adjustable mount
Beam separation: 4 mm
Beam separation: 12.5 mm
Beam separation: 25.4 mm
mm / kg
mm / kg
mm / kg
depending on design and material, in this case Al:
165 x 110 x 57 / 1.6
161 x 125 x 54 / 1.8
160 x 140 x 54 / 1.9
Size [L x W x H] / mass of electronics unit
mm / kg
450 x 400 x 150 / 8
Cable length between sensor head and electronics unit
m
3, optionally up to 10
Line voltage / frequency
VAC/Hz
100...240 /47...60
Laser safety class according to EN 60825-1 / ANSI Z136.1 (CDRH)
2M / II