16 Heat Flow Measurement
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16
Heat Flow Measurement
If the transmitter has the optional heat quantity measurement and two temperature inputs, the heat flow can be measured.
A temperature probe is fixed on the supply and the return line. For the mounting of the temperature probes see section
6.5.
The transducers are mounted on the return line (see Fig. 16.1). If this is not possible, they can also be mounted on the
supply line (see Fig. 16.2).
For the heat flow measurement, two different measuring modes can be used:
• The normal measuring mode (see section 16.2) can be used if in a heating application the transducers are mounted on
the return line.
• The BTU mode (see section 16.3) facilitates the measurement with other configurations (e.g., if the transducers are
mounted on the supply line or in a cooling application) and offers additional units of measurement for the heat flow.
A temperature correction value (offset) can be defined for each temperature input (see section 17.2.5).
If the supply or return temperature is known and constant during the whole measurement, this temperature can be entered
in the transmitter. In this case, the corresponding temperature probe does not need to be connected (see section 16.2.3 or
16.3.3).
If the supply pressure is constant or can be measured with an additional input, the heat flow can be determined for a me-
dium that is vaporous in the supply line (see section 16.6).
In the SuperUser mode, it is possible to define a temperature-based cut-off flow of the heat flow (see section 15.8).
The heat quantity is the totalizer of the heat flow (see section 11.2).
Fig. 16.1: Heat flow measurement with flow measurement on the return line
Fig. 16.2: Heat flow measurement with flow measurement on the supply line
supply line
return line
transducers
temperature probe
temperature input T2
temperature probe
temperature input T1
transmitter
supply line
return line
transducers
transmitter
temperature probe
temperature input T2
temperature probe
temperature input T1
Summary of Contents for FLUXUS F704**-A2 Series
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