Embedded system based data acquisition and control system for photoacoustic spectroscopic applications

• We prepared a controlling electronics for photoacoustic spectroscopy.
• We programmed FPGA in LabVIEW environment.
• We implemented PLL based digital lock-in.
• We tested the system made on the base of the new electronics.

Laser absorption spectroscopy by photoacoustic (PA) detection technique is increasingly used in trace gas analysis. Our research group focuses on related instrument and application development. In this paper the design and test results of a newly developed field programmable gate array based data acquisition and control system (DACS), are introduced. It became necessary to develop this new system since the limits of the old one had been reached; furthermore, it was challenging to implement new advanced measuring protocols. The system was designed to be scalable in order to be able to implement further ideas or measurement protocols without significant hardware or software modifications. In the current configuration, approximately 60% of the resources of the system are used. A complete PA measuring system was built around the new DACS to determine the analytical properties: the normalized noise equivalent absorption is 7.5 × 10−10 cm−1 W Hz−1/2, while the estimated dynamic range for measuring optical absorption is 7.5 orders of magnitude.