PMS – Phase measuring system
One of the most important prerequisites for the optochemical determination of various parameters based on fluorescent dyes is a measuring system which determines the phase shift produced by the dye.
The measuring system developed by researchers at the institute is based on the principle of synchronous detection: A periodical excitation signal is produced which, in combination with the optoelectronic unit, excites the dye. The signal emitted from the dye is detected, compared with the original signal and the complex vector (amplitude and phase) is determined.
The system enables an independent measurement with two optochemical sensor units. As the institute has access to integrated equipment for measuring temperature and air pressure, the system can be used as a stand-alone unit for the optochemical determination of oxygen and other parameters.
Communication with the measuring system occurs via an RS 232 interface, i.e. for sending configuration data such as excitation frequency and excitation amplitude. This allows measurement using different optical arrays and fluorescent dyes. A calibration can be carried out by entering the sensor data. The measuring data (oxygen, pressure, temperature, amplitude and phase) is output via this interface. An easy to operate LabView® program is used to control the system and display the measured data.