CB Watch 3 User Manual
v6.3 - May 2019
Page 37 of 100
Figure 47
–
Equivalent density lines and liquefaction curve
Gas sensors used
Two types of gas sensors are used depending on the options selected. Both output a
digital signal (rather than an analogue signal) and measure the following parameters:
•
Gas pressure and gas temperature
•
Gas pressure and gas tempe moisture level in gas
Sensor related alarms
In case the system loses communication with the gas sensor (for example if the cable
has been cut) and therefore there is no answer from the digital sensor, then the sensor
power supply is turned off and on again to reset the communication protocol and ensure
that it is not a communication
error. A counter is kept of the number of “no answer”. The
reset procedure may be repeated 3 times before the sensor is declared faulty and the
“Sensor absence” alarm is raised.
HMI: Measurements/Alarms
Figure 48
–
Gas sensor alarms
Whenever the sensor answers again
, the “no answer” counter is reset
automatically.