Refractive index or Abbe number ( v d or v e ) can be measured at different wavelengths
ranging from 450 to 1,100nm ( For measurement at wavelengths ranging from 681 to 1,100nm, the Optional Near Infrared Ray Viewer ( RE-9115 ) is required. )
The DR-M4 displays measurement result of refractive index or Abbe number digitally on the LCD.
Measurement can be achieved by matching the boundary line with the intersection point of the cross hairs.
This refractometer is connectable with digital printer DP-21 ( A ) ( Optional ) .

Model	DR-M4
Measurement range	Wavelength 450nm: Refractive index 1.5164 to 1.9164 Wavelength 589nm: Refractive index 1.4700 to 1.8700 Wavelength 680nm: Refractive index 1.4558 to 1.8557 Wavelength 1,100nm: Refractive index 1.4304 to 1.8303
Minimum indication	0.0001 in refractive index 0.1 in Abbe number
Measurement accuracy	± 0.0002 in refractive index ( with the attached test piece at 500 to 650nm )
Wavelength range	From 450 to 1100nm ( with interference filters ) ( For measurement at wavelengths ranging from 681 to 1100nm, the Near Infrared Ray Viewer ( Optional ) is required )
Measurement temperature range	5 to 50° C
Output terminal	For printer, DP-21 (A) (Optional)
Power supply	AC100 to 240V 50/60Hz
Dimensions and weight	Refractometer 13x29x31cm, 6.0kg Light source unit 15x33x11cm, 3.0kg
Optional	Cat.No.3011 Digital Printer DP-21 (A) RE-3520 589nm (D) Interference filter RE-3521 486nm (F) Interference filter RE-3522 656nm (C) Interference filter RE-3523 546nm (e) Interference filter RE-3524 480nm (F') Interference filter RE-3525 644nm (C') Interference filter RE-3526 Interference filter (select one wavelength) 450nm to 539nm 540nm to 680nm 681nm to 799nm 800nm to 1550nm RE-9115 Near-infrared ray viewer (with Adaptor)
Parts	RE-1640 Main & secondary prism for DR-M2 RE-4170 Illuminating lamp for DR-M2 RE-1592 Pack of desiccant tablets