EG&G Princeton 1235 Digital Triple Grating Spectrograph 1240 Spectral Camera

EG&G Princeton 1235 Digital Triple Grating Spectrograph 1240 Spectral Camera System

This is a complete EG&G Princeton Applied Research Model 1235 Digital Triple Grating Spectrograph system, paired with the EG&G Princeton Applied Research Model 1240 Spectral Camera and a full suite of HP peripherals. The 1235 is a computer-controlled triple-grating spectrograph designed for high-resolution optical spectroscopy across the UV-VIS range. It mounts three interchangeable ruled diffraction gratings and uses a motorized grating turret controlled via GPIB, allowing the operator to select grating and scan wavelength ranges from the host computer. The 1240 Spectral Camera serves as the array detector head, coupling to the spectrograph exit port and capturing spectral data across a defined wavelength range with 14-bit A/D resolution.

Specifications & What's Included

• EG&G Princeton Applied Research Model 1235 Digital Triple Grating Spectrograph Controller
• EG&G Princeton Applied Research Model 1240 Spectral Camera (Slit Option 1240/99)
• Grating 1: 150 g/mm @ Blaze 500 nm, ruled
• Grating 2: 300 g/mm @ Blaze 500 nm, ruled
• Grating 3: 1200 g/mm @ Blaze 500 nm, ruled
• Slit Width: 25 microns
• A/D Gain: 14 bits
• Active Wavelength Range: 200 nm (start) to 800 nm (end)
• Detector Model: 1453A
• GPIB Interface (HP-IB), Address 11
• HP 35731B CRT Monitor — 115/230 VAC, 50-60 Hz, 45W
• HP 46021A Keyboard — 12V DC, 25 mA Max, Made in Singapore
• HP 9122C Dual Floppy Disk Drive — 67W Max, 86–125V / 195–250V AC, Made in USA
• HP 98622A GPIO (GPIB) Controller Card — installed in HP computer chassis
• HP 7475A Pen Plotter
• Okidata Microline 182 Turbo 9-Pin Dot Matrix Printer
• HP computer chassis with expansion slots and rear I/O ports
• Interconnect cables
• Open equipment rack

Applications

The EG&G Princeton Applied Research 1235 is a research-grade triple grating spectrograph designed for laboratory spectroscopy applications requiring broad wavelength coverage and grating flexibility in a single instrument. Triple-grating systems like the 1235 were widely used in university and industrial research labs from the late 1980s through the 1990s for Raman spectroscopy, photoluminescence, absorption spectroscopy, and emission analysis across the UV-VIS spectrum (200–800 nm). The triple-grating configuration provides effective rejection of Rayleigh-scattered light without the need for external notch filters, making it well suited for Raman measurements near the excitation line. The 1240 Spectral Camera paired with a linear detector array allowed simultaneous multichannel detection rather than sequential scanning, significantly speeding up data acquisition. This class of instrument was a standard tool in semiconductor characterization, materials science, chemistry, and physics labs during its era. The system's GPIB interface allowed full computer automation through HP BASIC or compatible software running on the included HP workstation. Today these systems are sought by researchers maintaining legacy spectroscopy setups, by institutions with compatible detector arrays, and by hobbyist or educational labs building low-cost spectroscopy benches from surplus equipment.