| 摘要 |
PURPOSE:To enable the subtraction of a background by one luminous flux system, by providing two or more cells having one optical axis in common. CONSTITUTION:Cylindrical cells 2 are arranged so as to allow the center axes thereof to coincide with the optical axis 1 of modulated light. Both cells have mutually opposite polarities and the signal wires thereof are connected by an attenuator and are filled with xylene and the attenuator is adjusted so as to bring the sum of the signals from both cells to zero. A reference (solvent) cell and a specimen cell are arranged as mentioned above and, by subtracting a PA signal for a solvent from the PA signal of a specimen, the same effect as two luminous fluxes can be obtained by one luminous flux and the lowering in the intensity of incident light is eliminated and an optical system can be made simple. |
