[OPTICAL REVIEW Vol. 21, No. 3 (2014) 395-400]
© 2014 The Japan Society of Applied Physics

Optical Multi-Sensor for Simultaneous Measurement of Absorbance, Turbidity, and Fluorescence of a Liquid

Reetaleena RISSANEN1, Ilpo NISKANEN2*, Jukka Räty3, Pirjo Kyyrönen3, Asta LEINONEN3, Risto Myllylä4, and Kai-Erik PEIPONEN5

1Finnish Institute of Occupational Health, FI-53850 Lappeenranta, Finland
2Thule Institute, University of Oulu, FI-90014 Oulu, Finland
3CEMIS-OULU, University of Oulu, P. O. Box 51, FI-87101 Kajaani, Finland
4University of Oulu, Optoelectronics and Measurement Techniques Laboratory, P. O. Box 4500, FIN-90014, Oulu, Finland
5Institute of Photonics, University of Eastern Finland, P. O. Box 111, FI-80101 Joensuu, Finland

(Received September 18, 2013; Accepted December 16, 2013)

We have built a novel optical multi-sensor apparatus (MSA) for the measurement of light absorption, scattering and fluorescence either separately or simultaneous from a liquid. From the measured data it is possible to calculate different optical properties of liquid samples, such as absorbance and turbidity. The MSA is a portable device which is an advantage considering different field applications. The MSA was tested in laboratory conditions using well-known reference liquids. Data obtained with the MSA were compared with data obtained with a commercial spectrophotometer, fluorometer and a nephelometer, respectively. Relatively good correlations between the data of MSA and the three commercial devices were found. It is proposed that MSA is a potential device for monitoring changes of process liquids and liquid products in industry.

Key words: multi-sensor, transmission, scattering, fluorescence, liquid

*E-mail address: ilpo@niskanen@oulu.fi