Endress+Hauser RMS621, Operating Manual

Page: 73 / 90

Applications
Number of measurement points
The number of measurement points vary according to the unit model and application. For further
details, please see the table for applications/measurement points.
In general, the following measurements are possible:
Up to 3 measurement points with the input values (measurements) q, T. T
One measurement point is covered by the basic unit. Expansion cards are required if further
measurement points are to be added. Each expansion card is fitted with outputs
(analogue/impulse) for retransmission of process values. Relay outputs are also available.
Diagram/calculation formula
T
2
q T
1
Heat output (heating)
E = q (T
1,
p) [h (T
1
) – h (T
2
)]
Heat input (cooling)
E = q (T
1,
p) [h (T
2
) – h (T
1
)]
E: Heat quantity
q: Operating volume
: Density
T
1
: Temperature in inflow
T
2
: Temperature in return
p: Average operating pressure
h
(T
1
): Specific Enthalpy of water at temperature 1
h
(T
2
):
Specific Enthalpy of water at temperature 2