A Photomechanical Device for Triggering Digital Output on a GE Spectrophotometer.

Area of Science:

• Spectrophotometry
• Analytical Chemistry
• Instrumentation

Background:

• Modern spectrophotometry requires data compatible with automated processing.
• Older spectrophotometers, like the GE model, often lack direct digital output capabilities.
• Nonlinear wavelength representation in older instruments complicates data acquisition.

Purpose of the Study:

• To describe a photomechanical method for actuating the readout command of an old GE recording spectrophotometer.
• To enable direct data recording for automated processing.
• To address nonlinear wavelength representation issues.

Main Methods:

• A photomechanical system using an opaque disk with precisely placed holes was developed.
• The disk rotates in sync with the spectrophotometer's wavelength drive.
• Photodiodes and lamps aligned with concentric circles of holes trigger readout commands at set intervals.

Main Results:

• The method successfully actuates readout commands at 10-nm intervals across near-ultraviolet, visible, and near-infrared ranges.
• Data can be punched directly onto cards using an IBM 526 summary punch.
• An option for 5-nm interval data acquisition is available with a second disk.

Conclusions:

• This photomechanical approach effectively bridges the gap between older spectrophotometers and modern data processing needs.
• The system automates data acquisition, enhancing the utility of legacy spectrophotometric equipment.
• The method provides a cost-effective solution for digitizing spectral data from older instruments.