Humboldt State University
Robert A. Paselk Scientific Instrument Museum
This centrifuge was probably used for isolating precipitates in qualitative analysis in the General Chemistry course at Humboldt.
The centrifuge has a heavy, six place, cast aluminum, 10 1/2" angle head which doubles as a shield. It is enclosed beneath by a fitted spun aluminum cover for additional protection. There are six brass shields to fit 13x100 mm test tubes. The shields are made from tubing with rolled lips and soldered on bottoms. There is a small, conical, spun, aluminum cap covering the top of the rotor which attaches via a knurled screw to the shaft of the machine. The rotor is held on the motor shaft with a knurled screw which in turn has a threaded hole for securing the cap. The motor is mounted in a heavy cast iron base (7 1/2" dia. at base) finished in black crinkle paint. The instrument is 9 1/2" high. Speed is controlled with a Bakelite lever riding in a slot at the front of the housing. "OFF" and HIGH" are cast in raised letters at either end of the slot in the housing. It has a brown, two-wire, lamp-type cord Below the slot (and covering its entire length) is an aluminum tag with a frame and lettering in polished metal against a red background. OFF and HIGH are repeated on the tag with arrows) then serial [3348, stamped] then PHILLIPS / ST. LOUIS then, in a center red box, P / d, then DRUCKER / U. S. A., then volts [120, stamped]. There is a brass tag: HUMBOLDT-S-C 10021.
The aluminum and brass parts were mildly corroded and dirty when acquired. The rotor was removed, disassembled and cleaned with a brush. It was then treated with Briwax and steel wool to remove loose corrosion and to seal the metal, and then polished with a cloth. The Brass shields were also cleaned with Briwax and polished with a cloth. The painted housing with cleaned with a brush and then wiped and polished with Pledge using a towel.