Measuring instruments and equipment: Swiss Quality

Automatic Standard of
Refraction Index Measurement

Automatic Standard of Refraction Index Measurement Description.
Advantages: fully automated remote measurement method; application null-indicator instead autocollimator; expanded spectral range from DUV to IR through the use of:
integral detector instead matrix detector, mirror optic elements (mirror null-indicator, two-sided mirror); increase accuracy by averaging the results of angle measurement and data approximation.
Refractive Index Measurement Accuracy:standard uncertainty type A: 1,0 × 10^-6; standard uncertainty type B: 1,1 × 10^-6; total combined Standard uncertainty: 1,5 × 10^-6; expanded uncertainty (k=2): 3,0 × 10^-6.

All measurement operations are fully automatic.

These operations include:
  • Measurement of prism angles and minimum deflection angle. The uncertainty of angular measurements are less than 0.1 arcs;
  • High precision temperature measurement. Our digital thermometer allows measuring the absolute temperature with accuracy of 1 mK.

The minimum-deviation method of measurement is used because it enables one to attain the highest accuracy. Measurement method is applicable to solid and liquid substances.


Apex angle measurement accuracy 0,4"
Refractive index measurement range 1,0 ... 3,0
Refractive index measurement accuracy 1,5 · 10-6
Light sources He-Ne laser, Ar-Kr laser
Detector PbS, Photomultiplier tube, solid-state photodiode
Spectral range 193 nm ... 2300 nm

More information about Automatic Standard of Refraction Index Measurement (.pdf)

Article in Measurement Techniques about Standard (.pdf for registered users)

Fin-de-Praz 24, CH-2024 St-Aubin, Switzerland tel +41 (0)32 835 35 15 fax +41 (0)32 835 35 54