| 摘要 |
A device to measure the amount of light able to transmit through a liquid. The device uses a light detector and light source mounted to a support mechanism such that the detector and light source define a path of light emitted by the light source and detected by the detector. The device uses a structure designed to surround a liquid to be tested such that the structure allows light to transmit through the structure and the liquid. An actuator engenders relative motion between the support mechanism and the structure such that at certain times the light propagating between the light source and the detector passes substantially through the structure and the liquid to be tested such that the amount of light able to transmit through the liquid is detected by the detector, and at other times the light propagates directly from the light source to the detector without passing through the structure or the liquid such that the amount of light emitted from the light source is directly detected by the detector. A microprocessor then uses the two sets of detector readings to allow the transmittance measurement of the liquid to be compensated for errors introduced by drift and fluctuations in the amount of light emitted by the light source and also by drift in the light detector and electronics. Such fluctuation and drift is very common in light sources and is due primarily to changes in temperature and imperfections in the light source itself and the power supply. |
