The 4CTA measurement system is a 4-channel hotwire anemometer. Up to 4 hotwire probes can be operated simultaneously. Due to the extreme short response time, the system is particularly suitable for measurements of instationary flow processes. The system is shipped with calibrated and balanced hotwire probes and is ready to use out of the box.
The integrated USB data aquisition reads the sensor signals and sends them to a connected PC, where the raw data is instantly converted to the appropriate velocities.Furthermore additional sensors like microphones or acceleration sensors can be connected. The integrated 5 kHz  lowpass filter avoids alias-effects. Through the implemented barometer and the front connectable temperature sensor a determination of the air density is possible.

By high pass filtering of the velocity fluctuation signals the flow can be made audiable in real-time, giving an intuitive impression of the flow conditions. Since the ear is the best frequency analyser, the systems represents one of the most efficient methods to analyse aeroacoustic problems.