Study of non-contact type flowmeter for low flow rates using near-infrared light

摘要

We have proposed a novel method of non-contact thermal type measurement of low flow rate using the change in the absorption spectrum of water in the near-infrared wavelength range. With a prototype flowmeter using two detectors, we have made experiments and obtained calibration curves between the estimated and true flow rates. From the experimental results, we can measure the flow rates from 0.5 to 9 ml/min with the accuracy of about 10% of the flow rate. We also made a simulation of the flowmeter, and obtained agreement between the simulation and measurement. Discussions are made to improve the measurement accuracy.