The PCM 4 is a portable flow meter, suited for use in open channels, part full pipes and full filled pipes:
- open channel applications
- waste water collection systems
- storm sewer systems
- combined sewer systems.
The system is battery powered and provides high accuracy data on depth and velocity. This makes it particularly useful for infiltration / inflow analysis and reduction, master plan studies, and storm sewer monitoring.
Key Features
- Measures real flow velocity profile
- Spatial allocation of single velocities
- No calibration required
- Absolutely stable zero point and drift-free
- Triple redundant level measurement
- Measurement in all part filled, fully filled and open channels.
- Measurement in highly polluted and abrasive media
- Multilingual parameter setting in dialog mode
- Also available in PCM Pro, for use in Ex areas.
Theory: How It Works
The PCM 4 works on the principle that the wetted cross sectional area depends on the cross-sectional profile and the flow level. This level is determined via the use of internal or external sensors. The customer can select the type of sensor used depending on the circumstances:
- Water-ultrasonic integrated in combi sensor (measurement from bottom up). The flow level will be detected using the echo sounder principle. The interface between water and air (water surface) will be detected and the sound transit time will be monitored between the two.
- Pressure measurement cell integrated in combi sensor (measurement from bottom up). By detecting the atmospheric pressure and the hydrostatic pressure of the measurement medium simultaneously, air pressure fluctuations can be compensated.
- Wedge sensor with air-ultrasonic (measurement from top down). The flow level will be detected using the echo sounder principle. The interface between water and air (water surface) will be detected and the sound transit time will be monitored between the two.
- Variable external level sensor (4-20mA). These external sensors can be added into the system without any problems.
- Fixed value at constant fill level - no additional sensors are required.
The Nivus PCM4 uses the cross correlation method, meaning that echo image patterns are tracked over time. The temporal shift from first pattern to second can be converted directly into a flow rate. This is repeated up to 2000 times per second for high accuracy.
