Others

Brand: McPherson
Spectrogram-Measuring Microscope

This is a very rare item. It is a McPherson measuring microscope designed for critical measurement of spectral line separation. Plates can be scanned over an area of 250mm by 100mm. The measurement in the X-direction is via a scale on the front of the instrument graduated in single mms. Resolution is increased to 1 micron via a vernier on the 150mm diameter drum dial for the leadscrew. The leadscrew itself has a diameter of 25mm, with a pitch of 1mm.

The negative table can be released from the leadscrew easily for quickly checking other areas of the negative. The table can be moved in the Y-direction via a small knob on the left side of the platen, and the position read via a vernier to an accuracy of 0.1mm. There is also a small knob on the front of the table to the right which allows a very small adjustment of the theta angle so the negative scan is perfectly orthogonal.

No clamps are included for securing the spectral scans. There are bores on both sides of the long axis of the carrier, presumably for some sort of retaining system.

The microscope is suspended above the scan by a double-arm limb for extreme rigidity, but the focus adjustment is a conventional dovetail arrangement with rack & pinion. The microscope tube and focus drive are manufactured by Bausch & Lomb and date the instrument to the late 1950s or 1960s. There is a cross-line reticle in the focusable inclined ocular.

The instrument is missing the lamphouse, and the connection for the lamphouse appears to be unique. There is a standard fork-type 50mm adjustable microscope mirror in the base.

This is an incredibly finely crafted instrument in really spectacular condition (with a few minor chips in the paint on the back of the microscope support limbs). The leadscrew is in perfect condition, and all motions work flawlessly. The serial number of the microscope is 10024. Very uncommon.