18
June 2012
Gas Controller
AUTOMATIKPRODUKTER
Direction of the alarm release
In the gas measuring technique, most of the gases are monitored for their increasing concentration. For
example oxygen, however, is monitored for its falling concentration. In this menu there is the definition how
many of the 5 alarm thresholds monitor a falling concentration.
4.6.4
Measuring Range Definition
The measuring range can be adapted to the working range of the connected gas transmitter within 1 to 9999.
This also influences the display of the measured values, the alarm threshold as well as the hysteresis. Two
decimal places are displayed for measuring ranges <= 10, one decimal place for measuring ranges > 10 and
<= 100 and no decimal place for measuring ranges > 100.
4.6.5
MP Signal Definition
Gas transmitter using electro-chemical or catalytic beat gas sensors normally produce a linear signal,
proportional to the gas concentration.
Semiconductor gas sensors produce a non-linear (exponential) signal due to the measuring function. This
signal leads again to a non-linear 4 to 20 mA signal of the gas transmitter.
The Gas Controller CG-05 is prepared for both types of gas transmitters. The classification of signals is defined
in this menu.
Symbol
Description
Setting
Status
Function
MP01.1
Measuring Point
Selection MP No. bus or analog transmitter
Linear
MP Signal
linear
Linear = Transmitter with linear output signal
Non-linear = Transmitter with non-linear output signal
(semiconductor)
4.6.6
Threshold/ Hysteresis
For each measuring point five alarm thresholds are available for free definition. If the gas concentration is
higher than the set alarm threshold, the associated alarm is activated. If the gas concentration falls below the
alarm threshold inclusive hysteresis the alarm is again reset. In the mode “Alarm at falling” the corresponding
alarm is set in case of falling below the set alarm threshold. The display depends on the set measuring range:
see 4.6.4. Unused alarm thresholds have to be defined at measuring range end point, in order to avoid false
alarms.
Symbol Description
Default
Status
Function
MP01.1 Measuring Point
Selection MP No. / Bus or analog transmitter
80 ppm
Threshold
80
100
120
120
300
15
Threshold 1
Threshold 2
Threshold 3
Threshold 4
Threshold 5
Hysteresis
Gas concentration > Threshold 1 = Alarm 1
Gas concentration > Threshold 2 = Alarm 2
Gas concentration > Threshold 3 = Alarm 3
Gas concentration > Threshold 4 = Alarm 4
Gas concentration > Threshold 5 = Alarm 5
Gas concentration < (Threshold X –Hysteresis)
= Alarm X OFF
4.6.7
Delay for Alarm ON and/or OFF
Definition of delay time for alarm ON and/or alarm OFF. The delay applies to all alarms of an MP, not with
average value overlay, see 4.8.6.
Symbol
Description
Default
Status
Function
MP01.1
Measuring Point
Selection MP No./ bus or analog transmitter
0 s
Delay Time ON
0
Gas concentration > Threshold: Alarm is only activated at the end
of the fixed time (sec.). 0 sec. = No delay
0 s
Delay Time OFF 0
Gas concentration < Threshold: Alarm is only deactivated at the
end of the fixed time (sec.). 0 sec. = No delay
