Cambridge Sensotec Rapidox 1100L Oxygen Analyser Instruction Manual
To modify the oxygen analogue output range scroll down the menu to no.3 “Set
Outputs” and press ENT. Edit the lower and upper values in exactly the same
manner as described in 7.5 for setting the cal gas values. Once programmed the
new values remain in the memory until they are edited again in the future.
To select and modify the auxiliary outputs (pressure) scroll down to menu option
3 “Set Outputs” and pres ENT four times. Use the up and down arrow buttons to
program the pressure scale and press ENT. The permissible range is -2000mbar to
+2000mbar.
During initial warm up of the Rapidox when the display reads the serial number
the output sent to the rear terminal for oxygen will stay at 2mA (1V) which is the
standby signal. If at any stage a sensor becomes disconnected internally, or the
signal exceeds the measurable range for that sensor, then the display will indicate
there is a fault and the outputs will change to 1mA (0.5V) which is the sensor fault
signal. This will recover as soon as the sensor is reconnected and the fault
cleared. Additional current and voltage signals are provided by the analyser to
give an indication of various conditions and these are described in Table 1 below,
together with the status of the alarms during the condition:
O
2
Analogue Outputs
Alarms
(4)
Current
(2)
(4-20mA)
Voltage
(3)
(0-10V)
Description Explanation
There is a sensor fault on the oxygen
sensor, and/or the temperature sensor
has a fault condition, and/or the
pressure mode is set to automatic
(pressure compensation active) and
the pressure sensor has a fault
condition.
1mA 0.5V Fault
De-activated
2mA
1V
Start up
The analyser is still initialising.
De-activated
2.5mA
1.25V
Sensor under range
The sensor reading is under range.
Active
3mA
1.5V
Sensor over range
The sensor reading is over range.
Active
The sensor reading is in range but the
temperature sensor reading is out of
range, and/or the pressure mode is set
to automatic (pressure compensation
active) and the pressure sensor is out
of range.
Sensor operating out of
specification
3.5mA 1.75V
Active
The O
2
sensor and associated
(1)
sensor(s) are operating normally and
readings are in range.
4 to 20mA
0 to 10V
Normal operating output
Active
Aux Analogue Outputs
Alarms
(4)
Current
(2)
(4-20mA)
Voltage
(3)
(0-10V)
Description Explanation
1mA 0.5V Fault
The
assigned
sensor has a fault.
De-activated
2mA
1V
Start up
The analyser is still initialising.
De-activated
The assigned sensor reading is under
range.
2.5mA
1.25V
Sensor under range
Active
The assigned sensor reading is over
range.
3mA 1.5V Sensor
over
range
Active
The assigned sensor is operating
normally and readings are in range.
4 to 20mA
0 to 10V
Normal operating output
Active
Table 2: Analogue output settings and alarm status for certain conditions
Notes:
1
“Associated” sensors are the temperature sensor and the pressure sensor (when pressure mode is set to automatic).
2
The current outputs are active self-powered outputs - they are not loop powered.
3
The voltage (0 to10V) outputs produce non-zero voltages during start-up, fault and over/under range conditions - if
1V to 5V outputs are required, with these conditions indicated by corresponding voltages between 0V and 1V, the
current outputs can be used, with a 250 Ohm load resistor.
4
Alarms are de-activated during start up initialisation, and when a fault condition occurs on the assigned sensor.
Version 1.6
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Last printed 16/11/2011 16:59:00