Performance of a Double-Beam Recording Infra-Red Spectrophotometer

摘要: The performance of the Perkin-Elmer Model 21 Recording Infra-Red Spectrophotometer has been tested by measuring known spectra under a wide variety operating conditions. A complete infra-red spectrum in rock salt region can be recorded as graph percent transmittance vs. wave-length less than 10 minutes. At slower speeds resolving power varied from normal 30 to 40 up about 60 Rayleigh limit. For extreme resolution or stability, r.m.s. noise level 10−9 volts 2×10−10 watts at fastest response speed reduced far 4×10−11 increasing time. ranges conditions are: time, 4.5 110 seconds for full scale; scanning rate, 0.5 400 minutes per micron; chart scale length, 1 50 inches slit width, give constant energy levels between. 01 and 2 microvolts scale. effects scattered light atmospheric absorption bands are 3 throughout. Operation is automatic after selected instrument turned on. These features illustrated photographic reproductions original records with more detailed data on independent instrument’s critical parts.