
3 Types of totalizers
Manual TRZ 03· EN08 2018 September, 10th
44
LF and HF 1
1 Slot type initiator
HF (f
max
= 300 Hz)
(NAMUR)
2 Connector
3 Slot initiator
(Option, NAMUR)
LF (f
max
= 0,3 Hz)
4 Reed-Contact
(f
max
= 0,3 Hz)
Figure 10: Connector pin assignments for the HF 1 pulse transmitter
3.6.2
Pulse transmitters in measuring element (HF 2 and HF 3)
Notice
The higher-frequency flow signals from the HF 2 and HF 3 proximity sen-
sors are used for control purposes and in conjunction with electronic flow
computers suitable for custody transfer metering.
In the case of the HF 3 pulse transmitter, the pulses are picked off at the turbine
wheel, while they are picked off at the reference wheel for the HF 2 pulse transmit-
ter. The two wheels are arranged in such a way that two pulse series of the same
frequency are generated which are out of phase by 180°.
Notice
The exact frequency is determined during meter proving and is stated on a
supplementary data plate on the meter housing.