| 摘要 |
1, 169, 835. Spectrophotometer calibration. BECKMAN INSTRUMENTS Inc. June 6, 1968 [June 30, 1967], No.26886/68. Heading G1A. In a double beam optical null spectrophotometer in which a variable attenuator 23 is positioned in one path by a servomotor 22 responsive to a path difference signal and wherein the signal from a potentiometer 26 the slider 25 of which is movable with the attenuator is recorded at 27 as a function of wavelength a selector switch 28, trimming resistors 32 and calibration marks 34 on the attenuator are provided for calibration purposes so that the recorded output from the potentiometer is based on the inserted attenuation and not merely on the attenuator position. The paths are sequentually used by beams split by a rotating mirror 13 and recombined by a rotating mirror 14 a monochromator 15 dispersing the beam and directing a moving narrow bandwidth on to the detector 16. Potentiometer 51 and switch 55 provide for the alternative measurement of absorbance. The calibration steps are described and claimed. |
