Some applications which require the scattered light rejection of a double monochromator do not demand a higher resolution than that given by one of our single monochromators. This was the reasoning which led to the development of the DMc150. Designed as a double monochromator from scratch, the two halves of the DMc150 are housed in a single casting.

The optical layout not only results in a compact unit but also minimises the number of reflecting elements while maintaining the flexibility of the Czerny-Turner layout. In the case of the 'C' configuration, even the detector finds a space within the confines of the monochromator body. The DMc150 is used extensively for UV measurement (especially solar), in the measurement of high optical density, and in the determination of night vision compatibility of avionics displays.

Specifications:

Configuration: Two symmetrical Czerny Turner monochromators arranged for additive dispersion (or subtractive dispersion - factory set only)
Focal Length: Total focal length = 300mm, individual units = 150mm
Aperture ratio: F/4
Slits: Interchangeable fixed slits, micrometer adjusted, variable or motorised
Order sorting: Unit can be fully order sorted from 200nm to 30µm by using option 252 and Bentham OS series of order sorting filters
Gratings: 33mm square plain gratings kinematically mounted to allow change-over without loss of calibration. A range of gratings covers 200nm to 30µm
Resolution: Limit resolution with 1200 grooves/mm grating is better than 0.5nm
Stray Light: For measurement of notch filter in visible with quartz halogen light, stray light is less than 10-8
Wavelength scanning: By integral stepping motor and microstepping drive electronics
Maximum scanning speed: For 1200 g/mm grating maximum scanning speed is 30nm/second
Wavelength accuracy without software correction: ±0.3nm over normal operating range of 1200 g/mm grating
Wavelength accuracy with software correction: ± 0.05nm
Reciprocal dispersion: 2.7nm/mm with 1200 g/mm grating
PC interface: Integral IEEE-488
Power supply: Mains input 110/220V 50/60Hz
Weight: 12kg
Overall dimensions: 300mm x 400mm x 180mm high
Construction: Single aluminium casting with rebated lid