Macbeth TD-102 QuantaLog Transmission Densitometer 115V 60W Kollmorgen

Macbeth TD-102 QuantaLog Transmission Densitometer 115V 60W Kollmorgen

The Macbeth TD-102 QuantaLog is a benchtop analog transmission densitometer made by Macbeth Corporation, a division of Kollmorgen Corp., in Newburgh, New York. It measures diffuse transmission density (0–4 scale) and percent transmittance (0–100%) using an analog Weston meter movement, with a four-position color filter wheel for status and color-channel readings. The instrument uses a vacuum tube (valve) circuit internally, placing it firmly in the pre-solid-state era of photographic and graphic arts instrumentation.

Specifications & What's Included

• Model: TD-102 (QuantaLog)
• Manufacturer: Macbeth Corporation, Division of Kollmorgen Corp., Newburgh, NY USA
• Voltage: 115V AC
• Wattage: 60W
• Frequency: 50/60Hz
• Form Factor: Benchtop
• Display: Analog meter — Diffuse Transmission Density scale (0–4) and Percent Transmittance scale (0–100)
• Meter Movement: Weston (visible on meter face)
• Controls: Zero Adjust knob, Calibration knob
• Filter Wheel: 4-position rotating filter wheel with color caps (green, blue, red, clear/cream)
• Aperture: F 1mm (marked on sample stage)
• Internal Circuit Type: Vacuum tube (valve); RCA tube and one additional tube visible internally
• Internal Condition Note: Main transformer shows heavy rust and corrosion (visible in interior photos)
• Certifications visible on rating plate: SE, UL
• Unit only — no accessories or manual included

Applications

Transmission densitometers like the Macbeth TD-102 were standard instruments in photographic darkrooms, graphic arts departments, and film processing labs from the 1950s through the 1980s. They measure how much light a film negative, transparency, or other transmissive medium blocks, expressed as optical density or percent transmittance. The TD-102's color filter wheel allowed users to take density readings through specific color channels, which was important for color film analysis and color separation work in printing and reproduction. Macbeth Corporation was a well-regarded name in color measurement and densitometry, and the QuantaLog line was used in professional photographic production, quality control in film processing, and academic optical research. This is a vacuum-tube-era instrument, likely dating from the late 1950s to early 1960s, from a time before solid-state electronics replaced tube circuits in bench instruments. Collectors, restoration technicians, and labs maintaining vintage photographic or graphic arts workflows are the most likely buyers for a unit in this condition.