TMS 3000 averages the flow rate vz in the longitudinal direction of the tunnel (z-direction) through the tunnel cross-section and thus measures the actual volumetric flow rate of the air through the tunnel.
Transversal components vx and vy that are not involved in air transportation in the longitudinal direction z of the tunnel don‘t contribute to the measuring signal. Even larger traffic density in a tunnel cannot affect the measurement. The former can lead to significant measurement errors in ultrasonic measurements with time-of-flight method.
The measurement is implemented with the help of two special differential pressure chambers made of stainless steel that are measuring the flow velocity in z-direction due to their shape.
Thông số kỹ thuật
| Measuring ranges: |
-10 ... 0 ... +10 m/s
-15 ... 0 ... +15 m/s
-20 ... 0 ... +20 m/s |
| Accuracy |
< 0,1 m/s |
| Outputs |
4 ... 20 mA for the parameters:
- Flow rate at the Pitot tube A incl. polarity
- Flow rate at the Pitot tube B incl. polarity
- Average value of the flow rate (averaging over tunnel cross-section) incl. polarity
- Air temperature at the measuring point (-30 … +140 °C, optionally 30 ... +600 °C)
- Barometer pressure at the measuring point (600 ... 1100 mbar)
- Status signals
|
| Control input: |
Reduction of the averaging interval in case of accident |
| Service and parametrizing interface: |
I2C, on the front side of the evaluation unit |