Installation and Commissioning
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Manual TRZ 04 · EN04 · February, 1st 2017
38
2.5.5
Pulse transmitters in the meter head (LF)
The meter heads of the RMG TRZ 04 and TRZ 04-K and turbine meters are fitted with two
reed contacts as standard. The pulse value corresponds to the rotation rate U
a
. See the
indicating plate on the meter head for exact frequency data. The guide values are given in
the tables on pages 33-34. The maximum pulse frequency is 0.3 Hz.
2.5.6
Pulse transmitters in the measuring element (HF 2-D and HF
3-D)
The higher-frequency flow signals from the HF 2-D and HF 3-D proximity sensors are used
for control purposes and in conjunction with electronic flow computers suitable for custody
transfer metering. In the case of the HF 3-D pulse transmitter, the pulses are picked off at
the turbine wheel, while they are picked off at the reference wheel for the HF 2-D pulse
transmitter. 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°. The exact frequency is
determined during meter proving and is stated on a supplementary data plate on the meter
case. The guide values are listed in the tables on pages 33-34. The maximum pulse
frequency is approx. 2100 Hz at Q
max
, but depends on the meter size.
2.5.7 Tamper
contact
A tamper contact is located directly next to the two reed contacts in the meter head. If the
attempt is made to block the reed contacts with a magnet held on the meter head, this
contact switches.
In passive state this contact is closed.
2.5.8 Encoder
With the rotary encoder type ENCO 08 the absolute totalizer reading of the mechanical
index is acquired and transmitted as a data record to a volume corrector. The encoder is
energy self-sufficient, which means, no battery or external power supply is necessary for
the operation. The energy required for digital transmission of the totalizer reading is
provided by the connected auxiliary device (volume corrector).
