Spectrometer Specifications Polychromator The high energy echelle-based Optima polychromator utilizes one or two SCD detectorsdepending on the Optima model. The measured resolution of the system is 0.006 nm at 200 nm. The 80 by 160 mm echelle grating (manufactured by PerkinElmer) has 79 lines per mm and a blaze angle of 63.4 degrees. With the Optima 4300 DV, a 60-degree fused-quartz prism is added as the cross disperser for the visible region (403 - 782 nm). The UV disperser on all Optima 4000 DV series of spectrometers incorporates Schmidt correction into its surface to eliminate aberration for the 400-mm radius camera sphere. The entire optical system is enclosed in a purged and thermostatted optical enclosure. The optical enclosure is mounted on the same, large optical bench as the sample introduction system. The optical bench is shock-mounted to the frame of the instrument so that normal floor vibrations do not affect system performance.