Instruments SA Incorporated monochromator in excellent condition. This ¼ meter instrument features micrometer adjustable slits on both entrance and exit ports. There is also a mechanical digital readout for the grating position, however the readout does not correlate directly with frequency (although it is highly repeatable). It is possible to configure this in an ‘in-line’ arrangement, but to do so would require an additional mirror on a post, and it is not included. Presently it is set up in a right-angle configuration. There is an additional ‘output’ port on the side of the instrument with the input port (partly occluded by the diverter mirror. It appears that either a camera system or a lamphouse could be attached at this position if the diverter mirror is removed (the diverter mirror mount is indexed).
All adjustments on the monochromator are manual (both slits and grating position for frequency). There is an internal belt linkage drive with a keyed drive shaft for the grating The grating itself appears to be 1200 lines/mm (it isn’t marked however), and is in very good, although not pristine, condition. There is a very light finger print in one corner of the grating. There is also a bit of haze on the two primary mirrors and a bit stronger haze on the deflection mirror, but the monochromator still functions very decently. For optimal performance all three mirrors should be resilvered. Both collimation mirrors are 85mm in diameter, and the grating is 50mm square.
Mechanically, the instrument is in superb condition – all the controls work very smoothly and everything is very clean. Cosmetic condition of the instrument is excellent with a few light scuffs here and there.
The second to last photo shows the wavelength setting apparatus (bottom cover removed). There is a very large lead screw and a compound cam system that runs along the hardened and ground steel bar. As can be seen the manual drive (with the mechanical readout) directly drives the linkage for the motor drive. This in turn drives the lead screw at at 1:2 ratio (even though the manual drive shaft is 'in-line' with the lead screw, there is no direct connection - it is driven by the countershaft with the drive spline attached).
The model number on the instrument is HR 320, serial number 5700-4-82. Side label states the instrument is intended for gratings of 1200 or 2400 grooves per mm. Visually, the instrument will fully scan the visible spectrum with a decent amount of motion on either side of the visible band, but I am not sure of the actual spectral output range. There is a handwritten tag on the side of the instrument next to the mechanical counter that states 5461 = 5112. I had assumed this might mean that a reading of 5461 would yield a wavelength of 511.2 nm, which should be a strong blue-green color, however the wavelength appears to be much nearer 400nm – it is a deep violet.
Listed price is for the instrument in the present ‘as-described’ condition. If you would wish us to refurbish the instrument (resilver the three mirrors and recalibrate the readout for several wavelengths in the visible spectrum, we can provide that service for an additional $1100.00. Please inquire
Photo set 648