Measurement Principle

The FCX-MC sensor module is a complete solution that can rapidly and accurately measure oxygen concentration within the ranges of 0...5%, 0...25%, or 0.1...95%.

Sensor and measurement electronic components are located on the PCB (FCX-MCxx-FLOW and FCX-

On the MCxx-DIFF, the oxygen sensor can be connected to the PCB via a cable (FCX-MCxx-EXT). The microcontroller on the PCB linearizes the sensor signal.

In accordance with IEC 60381 and output in analog form as current or voltage (current)Signal (0) 4-20mA, or 0-10V DC.

Sensor signals can also be output via RS232/RS485 interfaces.

When zirconia is heated to approximately 450°C, oxygen ions can penetrate (see the operation principle in the above figure).

Voltage applied to the sensor will pump oxygen out of the cavity. At a constant gas pressure, the amount of oxygen pumped out is equal to that diffusing in through the capillary.

The number of oxygen molecules, and within a certain range, it is unrelated to the voltage applied between the electrodes.

The measurement of current is directly proportional to the number of oxygen molecules removed. The relationship between oxygen partial pressure and sensor current is given by the following equation:

Is = c In (1 - pO2 / pt) Here:

Is: Sensor Output Current

Coefficient (sensor coefficient varies) pO2: Oxygen partial pressure

Total Gas Pressure

Sensor module performs four tasks:

Adjust the heating power of the sensor

Amplify microamp signals from the sensor

Oxygen partial pressure linearization with respect to sensor current

· Convert the amplified signal into a standardized voltage/current output signal

Sensors and modules are paired and calibrated at the factory to achieve a sensor temperature of 450°C.

Heating voltage must be customized and adjusted for each sensor, so sensors cannot be directly replaced and are not compatible with other modules. All modules on the PCB

Each has a label with sensor number and corresponding module number.

Warm-up period

The module requires approximately 5 minutes of preheating. During this time, the green LED will blink (■□■□■□■□■□...).

Oxygen concentration will display zero (simulated output = 0 mA). When the module is ready for measurement, the green LED will almost continuously light up.

(■□■■■■■■■■■□■ ...) When the module is ready for measurement, the green LED is almost continuously in a short blink state (flashing at intervals of 5-10 seconds).

Indicates the module is operating normally. In this mode, the oxygen sensor is heated under the specified voltage level.

The output of oxygen is a linear relationship between the oxygen concentration and the sensor current.

Environmental Conditions

No outdoor use permitted.

Moisture-proof treatment required

Sensor temperature is approximately 450°C. Always be aware of the hazards and risks associated with gas applications under any circumstances.