1.Principle

KFDO310 integrated on-line fluorescence dissolved oxygen sensor is designed and made based on the quenching principle of excited fluorescence of specific substances in physics. The blue light from the light-emitting diode illuminates the fluorescent material on the inner surface of the fluorescent cap. The fluorescent material on the inner surface is excited and emits red light. By detecting the phase difference between the red light and the blue light, and comparing it with the internal calibration value, the concentration of oxygen molecule can be calculated, and the final value can be output by temperature automatic compensation.

2.Feature

• No electrolytes, no polarization
• No need to consume oxygen, not affected by the flow rate
• Built-in temperature sensor, automatic temperature compensation
• Free from chemicals like sulfides
• Small drift, fast response, more accurate measurement
• Maintenance-free, long service life, lower use cost
• Fluorescent caps are easy to replace
• RS-485 interface, Modbus-RTU protocol

3.Technical Specifications

4.Dimensional Drawing

5.Installation and Electrical Connection

Installs

The temperature sensing part should be immersed below the liquid surface to avoid collision with the film head surface. The head part of the membrane should be free from sediment.

Pulsed Polarographic Dissolved Oxygen Sensors

Pulsing polarographic dissolved oxygen sensors remove the need to stir a sample for accuracy when measuring dissolved oxygen. A rapid-pulse DO sensor is similar to a steady-state polarographic DO sensor as both utilize a gold cathode and silver anode. Both steady-state and rapid-pulse sensors also measure dissolved oxygen by producing a constant voltage to polarize the electrodes ⁷. However, these pulsing polarographic DO sensors turn on and off approximately every four seconds, allowing the dissolved oxygen to replenish at the membrane and cathode surface ⁷. This replenishing creates a flow dependence of almost zero ⁷. In order to consistently polarize and de-polarize the electrodes for these short time periods, a pulsing polarographic DO sensor includes a third, silver reference electrode, separate from the silver anode ⁷. The electrochemical reaction (silver oxidation and oxygen reduction) remains the same.

As rapid-pulse polarographic sensors reduce flow dependence when taking DO measurements, the water sample does not need to be stirred when using this sensor.