Burkert Type 1150 - Manual (Page 78)

76 - 1150
C
ONFIGURATION
C-level control
C-level control is used for the control of carbon in the atmosphere of a gas coking
furnace. The C-level is determined through the oxygen measurement with a zircon
dioxide sensor and measurement of the sensor temperature.
C-level control is an extra.
Configuration
Analog inputs
Controller
Generator
Limit comparators
Outputs
Logic functions
Math / logic
C-level
Display
Interfaces
Device data
Recording
C-level calculation
The calculations of the controller are based on the following:
E - e.m.f. of the zircon dioxide sensor
T - sensor temperature in K
P
co
- partial pressure CO in percentage of volume
C
p
- carbon level
E = 0.0992 T { -lg (P
CO
) + 1.995 + 0,15 C
p
+ lg(C
p
) } mVK + 816.1 mV
Sequence control
Operation using a zircon dioxide sensor is subject to a fixed time schedule. The sensor has to be “flushed”
at regular intervals (cycle time) to ensure faultfree measurement.
During flushing and the subsequent recovery time, the controller is in manual mode. The latest
measurement is stored. The average value of the most recent outputs is produced.
During flushing, the output variable logic 1 is “1” The flushing procedure can be controlled by linking it to an
output.