Charact - Select The Transfer Characteristic Between Input Signal (Position Set-Point Value) And Stroke - Burkert 8692 Operating Instructions Manual

Type 8692, 8693
Auxiliary functions
25.2.1 C HARACT – Select the transfer characteristic between
input signal (position set-point value) and stroke
Characteristic (customer-specific characteristic)
Use this auxiliary function to select a transfer characteristic with reference to set-point value (set-point position,
CMD) and valve stroke (POS) for correction of the flow-rate or operating characteristic.
Factory setting: linear
Each auxiliary function, which is to be set, must be incorporated initially into the main menu (MAIN).
See chapter "25.1 Activating and deactivating auxiliary functions", page 108.
CHARACT
ENTER
EXIT
* EInput the nodes see chapter "25.2.1.1. Inputting the freely programmable characteristic"
Figure 61: Operating structure CHARACT
The flow characteristic k = f(s) indicates the flow-rate of a valve, expressed by the k
V
s of the actuator spindle. It is specified by the design of the valve seat and the seat seal. In general two types of flow
characteristics are implemented, the linear and the equal percentage.
In the case of linear characteristics identical k
⋅ ds).
(dk = n
V lin
In the case of an equal percentage characteristic an equal percentage change of the k
stroke change ds.
(dk /k = n
V V equalper
The operating characteristic Q = f(s) specifies the correlation between the volumetric flow Q in the installed valve
and the stroke s. This characteristic has the properties of the pipelines, pumps and consumers. It therefore exhibits
a form which differs from the flow characteristic.
linear
GP 1:25
GP 1:33
GP 1:50
GP 25:1
GP 33:1
GP 50:1
FREE
value changes k
V
⋅ ds).
SELEC Linear characteristic
Equal percentage characteristic 1:25
Equal percentage characteristic 1:33
Equal percentage characteristic 1:50
Inversely equal percentage characteristic 25:1
Inversely equal percentage characteristic 33:1
Inversely equal percentage characteristic 50:1
*. . U ser-defined characteristic, freely program-
mable via nodes
value depending on the stroke
V
are assigned to identical stroke changes ds.
V
english
value corresponds to a
V
111