14. Pulse Generators
Two low frequency (LF) pulse generators are plugged to the meter index head
in standard delivery. A third low frequency (LF) pulse generator is optional.
The function of these three LF-pulsers is:
•
1 LF-pulser for flow measurement
•
1 additional LF-pulser for flow measurement (option)
•
1 LF-pulser as anti tampering contact.
Figure 5: The LF assembly
Figure 6: Installed LF
assembly with the MQM Quantometer
As an option one high frequency (HF) pulse generator can be installed onto the meter.
The function of the HF pulser is the determination of the actual gas flow in high resolution.
The HF-pulser follows NAMUR specification and is typically connected to the input of flow
computers or appropriately equipped volume correctors. For the connection use shielded
cable.
The blades of the turbine rotor are scanned by the high-frequency sensor. Each blade passing
the HF-sensor creates a pulse. Figure 7 shows a MQM Quantometer with fitted HF-sensor.
Abb. 7: MQM Quantometer mit HF-Sensor
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