1、 Measurement principle
The YDO-628 fluorescence dissolved oxygen analyzer is based on the quenching principle of specific substances on active fluorescence in physics. The fluorescent substance at the front end of the sensor is a special composite of platinum metalloporphyrin and polyester foil that allows gas to pass through. The surface is coated with a black light blocking material to avoid interference from sunlight and other fluorescent substances in water
　2、 Product Features and Applications
　Product Features
Fluorescence method principle, no need to replace the membrane and electrolyte, basically maintenance free;
No need to replace the fluorescent cap, lower usage cost;
No oxygen consumption, no requirements for flow rate and agitation;
　　Not affected by chemical substances such as sulfides;

Higher resolution and measurement accuracy;
Chinese menu and convenient button operation;
4~20mA isolated current output, optional fieldbus interface;
Output of upper and lower limit alarm relays;
　Product application
Wastewater treatment: regulating tank, aeration tank, aerobic/anaerobic digestion tank, and effluent detection, etc.
Industrial process: monitoring the water quality of production recycled water, recycled water, etc. Water environment testing for rivers, lakes, seawater, fishing grounds, and aquaculture.
3、 Technical indicators
　　Transmitter:
1. Measurement range: Dissolved oxygen: 0~20mg/L Air saturation: 0~200%
2. Display mode: LCD
3. Measurement units: available in both% and mg/L
4. Resolution: 0.01%
5. Accuracy: ± 1.0% FS
6. Repeatability: ± 1.0% FS
7. Power: ≤ 10W
8. Analog output: 4~20mA, load 750 Ω
9. Switch output: 2 relays, capacity 220VAC/2A
10. Power supply: AC220V ± 10%
　Sensor:
1. Material: 316 stainless steel or PVC
2. Cable: Shielded cable
3. Installation method: immersion type
4. Process connection: ZG1
5. Dimensions: Φ 60 × 112mm
6. Medium pressure: ≤ 3bar
7. Signal cable: 10M (standard) extendable
8. Protection level: IP68
9. Working temperature: -20~60