The passive-drawn fiber optic liquid analysis technique, which is one new kind liquid analysis technique, is proposed.
Based on the analysis technique, the passive-drawn fiber optic liquid analyzer is designed. The working principle of the
analyzer and the design of the fiber-optic probe are introduced. The drawn type analysis technique is different from the
traditional feeding liquid drop analysis technique. By controlling the measured liquid level ascending and descending
again and again, the probe enters and exits the liquid repeatedly, and so a small liquid drop is formed at the end of the
probe. By analyzing the light intensity signal reflected from the liquid drop, the physical and the chemical property
parameters of the measured liquid are attained. The technique has the advantage of better repeatability and more
information of the measured liquid could be gotten. Furthermore, the measuring result is not influenced by the former
liquid because the fiber-optic probe can be cleaned easily and completely. Experimentally, some liquid samples have
been characterized, and the information of the concentration, surface tension and viscosity is obtained. The experiment
indicates that the passive-drawn fiber-optic liquid analysis technique can be used to detect the information of liquid.