17
4: Normal Operation
The
Dual O2/CO2
monitor is a single point monitor designed for the continuous
detection and measurement of ambient oxygen concentration levels.
4.1 Signal Outputs
The
Dual O2/CO2
monitor outputs a continuous 4-20 mA analog signal proportional to
the measured concentration of either oxygen or carbon dioxide.
The 4-20 mA output
can only be used for gas.
When oxygen is selected 4 mA represents 0% O
2
and 20
mA represents 25% O
2
which is the full range for oxygen. When carbon dioxide is
selected 4 mA represents 0ppm and 20 mA represents 10,000ppm which is the full
range for carbon dioxide. In the event of a system fault, a specific factory defined code
will be displayed on the local digital display. This code will indicate the exact nature of
the system fault.
4.2 Instrument Faults
The
Dual O2/CO2
monitor incorporates a number of self-checking features to ensure
reliable operation. In the event that a fault condition is detected, the analog output signal
is altered as follows:
Condition
Analog Signal
**Supply Voltage Out of Range
Fault code 16
Analog output drops to 2 mA
Transmitter cable cut
Analog output drops to 0 mA
O
2
Cell complete failure
Fault Code 128
Analog output drops to 2 mA (0 mA on request)
Fault Relay activates
(Available with Relay Option Only)
O
2
/ CO
2
System Warm-Up
Analog output drops to 2 mA
Fault Relay activates and turns off when system is
in the Oxygen operation mode
(Available with Relay Option Only)
O
2
Cell voltage fault
Fault Code 64
Analog output drops to 2 mA (0 mA on request)
Fault Relay activates
(Available with Relay Option Only)
EEPROM Fault 08
Analog output drops to 2mA (0 mA on request)
NOTE
:
All system faults are displayed on the front panel. Each fault has its own
specific code to identify the specific problem. Please contact CONCOA whenever
a fault is displayed.
** When using your own power supply please ensure that the voltage is
regulated to 24VDC +/- 0.5 volts. If the voltage is too low or high you will activate
a Supply Voltage Out of Range fault and disable the monitor.