A Rapid Method for Measuring Rhodamine B Concentration Based on a Y-type Optical Fibre System
X-Y. Zhu and Z-M. Zhao
A novel method for measuring rhodamine B (RhB) concentration based on Y-type optical fibre sensor is presented in this paper. The measurement system mainly consists of laser, Y-type optical fibre sensor, detector, amplifier, A/D converter and microprocessor. By detecting the voltages, V1 and V2 of the reflected light intensity corresponding to two depths,
ln (V2 / V1) is calculated and applied to establish the calibration model with the rhodamine B concentration. The equation of the model is
ln (V2 / V1) = 0.0374c, with correlation coefficient of 0.977. In addition, a prediction experiment is carried out to verify the effectiveness of the measurement method (recovery is between 96.75 and 102.68%). Results of this study indicate the feasibility of using this technology for measuring rhodamine B concentration rapidly and in real-time. This new approach is also suitable for the configuration and detection in dye production.
Keywords: Diode laser, rhodamine B (RhB), Y-type fibre sensor, rapid measurement, linear fitting, recovery experiment, light intensity