JUMO 703041 - Page 68

10 Extra codes
68
Humidity control A psychrometric humidity sensor is used to determine relative humidity, through the
mathematical combination of wet bulb and dry bulb temperatures.
relative humidity: (E1, E2)
For the controller to function as a humidity controller, further settings have to be made:
- controller process value: math 1
v Chapter 8.2 “Controller “Cntr””
If the value for relative humidity needs to be displayed, then one display must be con-
figured to “Math 1”.
v Chapter 8.7 “Display “diSP””
Ratio
control
The control is always based on analog input 1 (E1).
The math module forms the ratio of the measurements from E1 and E2, and produces
the setpoint for the controller. The ratio of the measurements can be called up through
the function “Math 1” and displayed.
The required ratio E1/E2 is programmed as the setpoint (ratio setpoint) in the setpoint
definition.
Ratio: E1/E2
For the controller to function as a ratio controller, further settings have to be made:
- controller process value: analog input 1
- external setpoint: ramp end value
v Chapter 8.2 “Controller “Cntr””
If the ratio needs to be displayed, then one display must be configured to “Math 1”.
v Chapter 8.7 “Display “diSP””
Upper
display
Math
x
w
E1
E2
E1
E2
w
x
= analog input 1
(dry bulb temperature)
=2
(wet )
= setpoint
= process value
analog input
bulb temperature
%
Upper
display
E1 / E2
wv
wv
Math
w
x
E1
E2
E1
E2
w
wv
x
= analog input 1
=2
= setpoint
= ratio setpoint
= process value
analog input
E2
*