Model 654 Detector Assembly

This detector assembly is designed for use ,with McPherson Vacuum UV monochromators and is sensitive to radiations through a wavelength range of 300 A to 6,000 A. It may be connected directly to the exit slit, or to a sample chamber that is attached to the exit slit, of the monochromator. It is safe, compact and easily attached.

• Wide range of sensitivity (300 A - 6,000 A).
• Linear detector through a range of 300 A - 3,000 A.
• Sensitive detector with selected PM tube with low dark current.
• Provides effective shielding against electrical noise.
• Operates in atmosphere, thus eliminating the danger of corona discharges when operating voltages are applied at reduced pressures.

In normal use, ultraviolet radiations leaving the exit slit of a monochromator pass directly to a sodium salicylate coated vacuum-tight window, causing it to fluoresce. In some experimental setups, the ultra-violet radiation passes through sample chambers or materials under test (gas samples, windows. filters. etc.) before striking a sodium salicylate coated window.

The fluorescent energy (at a wavelength of approximately 4,000 A) passes through an air space, through the window of the photomultiplier envelope and strikes the photocathode surface. With the proper power supplied to the photomultiplier, it converts the light energy striking its cathode into an electrical signal that can be amplified and read out on a strip chart recorder.

The combination of sodium salicylate coating and photomultiplier tube supplied in this model is sensitive to radiations from 300 A to 6,000 A and is reasonably linear through the range of 300 A to 3,000 A.

McPherson, Inc.