4CTA Hotwire Bridge – (Example configuration)
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.
| Velocity range | 0.1 – 50 m/s in air (calibrated) higher velocities possible, depending on temperature |
| Frequency resolution | 0…5 kHz with 3dB lowpass, unfiltered up to 10 kHz is optional |
| Ambient conditions for hot-wire probes | |
| Fluid | Air, different non-corrosive gases are possible but must be calibrated separately, no particles, no air pollution |
| Temperature | 10…50°C within factory calibration, -10.60°C possible |
| Humidity | Non-condensing |
| Data acquisition card (option 4CTA-DAQ) | |
| National Instruments USB-6211 (different data acquisition card optional on request) | |
| Analogue inputs | 16 channels, 16bit, 250kHz total sampling rate |
| Analogue outputs | 2 channels, 16bit |
| Digital in- and outputs | 4+4 channels, including 1 counter |
| Further intern components | |
| PT100 amplifier | 0…300°C default, configurable |
| Barometric pressure sensor | 800…1100 hPa |
| CTA-Mainboard | Supply and signal conditioning eCTA/eCCT, per hot-wire probe |
| Power supply | |
| AC | 110…264 V, 47-63 Hz, 100 W |
| DC | 11…18 V, min 4 A, 40 W (Binder 712 2 pin) |
| Configuration of signal inputs and signal outputs – connections front side | |
| 1x PT100 temperature sensor | Binder 712, 2 pin |
| up to 4 hot-wire probes | Binder 712, 7 pin |
| Audio volume and channel selection switch | |
| Earphones | 3.5 mm audio jack |
| up to 10 analogue inputs | BNC or customized |
| up to 2 analogue outputs | BNC or customized |
| Digital in- and outputs | D-Sub 9 pin or customized |
| Ambient conditions for electronics | |
| Temperature | 5…40°C |
| Humidity | Non-condensing |
| Dimensions | |
| case (H x B x T) | 134 mm x 234 mm x 333 mm (19’’ 3HE 42TE) |
