This specially developed, high-efficiency diffraction grating is 100 times more efficient than acetate gratings. It can produce a spectrum bright enough for vivid classroom discussions even in rooms that do not darken. The shape of the grating surface produces a dispersion angle of 23.5 degrees and a groove separation of 19,050 lines per inch (750 lines per mm) for a wavelength of 550 nm. The sinusoidal shape of the grating surface places most of the light in the first order image. This shape is embossed in a polyester plastic. It can be used to make a spectrometer, a spectrum projector, or used with an overhead projector to produce a projected spectrum for demonstration purposes. Some of the gratings come with four color filters: blue, red, green, and yellow. Used singly and in combination, you can demonstrate how light is affected by color filters, or how objects of a certain color appear when bathed in light of another color.

• PS-08A: 2 sheets, each 5 x 5 inch $11.00
• PS-08B: 6 foot x 5 inch roll (13 5" x 5" squares) $47.00
• PS-08C: 5 x 5 inch sheet with 4 color filters $9.25
• PS-08D: 4.75 x 4.75 inch sheet mounted in plastic with filters $35.00
• PS-09: 10 slides, each in a 35mm glass slide mount $32.50
• PS-09/Single: 1 35mm glass slide mount $5.00