Simultaneous measurements of flow velocity and concentration with a photothermal velocimeter using an optical fiber heterodyne interferometer
Abstract
This paper describes a new method for simultaneous measurements of flow velocity and concentration using the photothermal effect. An optical fiber heterodyne interferometer is used to detect the photothermal effect sensitively. We chop CW CO2 laser mechanically to obtain a pulse pump beam of stable power. The laser pulse width influences on the concentration measurement. We developed the method using time derivative of initial phase variation to eliminate the influence of the laser pulse width. The reliability of the method is confirmed theoretically and experimentally.
- Publication:
-
Laser Anemometry - Advances and Applications 1991
- Pub Date:
- 1991
- Bibcode:
- 1991laaa.conf...83N
- Keywords:
-
- Fiber Optics;
- Interferometers;
- Optical Heterodyning;
- Optical Measuring Instruments;
- Velocity Measurement;
- Phase Deviation;
- Pulse Duration;
- Instrumentation and Photography