CPC G01N 30/74 (2013.01) [B01J 20/291 (2013.01); G01N 1/14 (2013.01); G01N 21/41 (2013.01); G01N 30/32 (2013.01); G01N 2030/027 (2013.01); G01N 2030/326 (2013.01)] | 13 Claims |
1. A measurement method of a differential refractive index between a sample liquid and a reference liquid by sending the sample liquid to a sample cell with a sample pump, sending the reference liquid to a reference cell with a reference pump, and detecting a change in direction of travel of light sequentially transmitted through the sample cell and the reference cell with a light detector, the measurement method comprising:
determining an adjustment value of a phase difference between the sample pump and the reference pump based on noise waveform informations that occur in an output signal of the light detector, so that the phase difference is adjusted according to a difference in lengths of channels of the sample liquid and the reference liquid or a difference in devices connected to the channels of the sample liquid and the reference liquid; and
adjusting the phase difference between the sample pump and the reference pump before starting measurement of the differential refractive index, wherein
during the adjusting of the phase difference, adjusting the phase difference between the sample pump and the reference pump so that a noise that occurs in the output signal of the light detector by propagation of pulsation from the sample pump within the sample cell and a noise that occurs in the output signal of the light detector by propagation of pulsation from the reference pump within the reference cell cancel each other.
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