Rh Function Block - Honeywell UMC800 Reference Manual

Function Blocks

2.54 RH Function Block

Description
The RH label stands for Relative Humidity. This block is part of the Calculations category. It looks like
this graphically on the Control Builder.
Function
Calculates RH as a function of wet bulb temperature, dry bulb temperature and atmospheric pressure.
0-100% RH is output as a floating point number between 0 and 100.
Input
DRY = Dry Bulb Temperature (°F, metric = °C)
WET = Wet Bulb Temperature (°F, metric = °C)
PRES = Atmospheric Pressure (psi, metric = Pa)
Output
RH = Relative Humidity (0-100)
Block Properties
Double click on the function block to access the
function block properties dialog box.
Block Order (Read Only)
You can change the assigned execution order
number by selecting "Execution Order" in the
"Configure" menu and arrange the order to suit
your control strategy.
Metric System
Click on this box to select Metric Units.
Table 2-47
lists the units for the inputs and
outputs.
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