PFDO-800 Fluorescence Dissolved Oxygen Sensor Operation Manual

Chapter 1  Product Specifications

Specifications Details
Size Diameter 49.5mm*Length 251.1mm
Weight 1.4KG
Main Material SUS316L+PVC (Ordinary Version), Titanium Alloy (Seawater Version)
O-ring: Fluoro-rubber
Cable: PVC
Waterproof Rate IP68/NEMA6P
Measurement Range 0-20mg/L(0-20ppm)
Temperature: 0-45℃
Indication Resolution Resolution:±3%
Temperature: ±0.5℃
Storage Temperature -15~65℃
Environment Temperature 0~45℃
Pressure Range ≤0.3Mpa
Power Supply 12 VDC
Calibration Automatic air calibration,Sample calibration
Cable Length Standard 10-Meter Cable, Max Length: 100 Meters
Warranty Period 1 Year
External Dimension

Table 1  Dissolved Oxygen Sensor Technical Specifications

Chapter 2 Product Information
The dissolved oxygen sensor measures the dissolved oxygen by the fluorescence method, and the emitted blue light is irradiated on the phosphor layer. The fluorescent substance is stimulated to emit red light, and the oxygen concentration is inversely proportional to the time when the fluorescent substance returns to the ground state. By using this method to measure the dissolved oxygen, it will not produce oxygen consumption, thus assuring data stability, reliable performance, no interference, and simple installation and calibration.
The product is widely used in sewage plant, water plant, water station, surface water, farming, industry and other fields. Dissolved oxygen sensor appearance is shown as figure 1.

Figure 1  Dissolved Oxygen Sensor Appearance

1- Measurement Cover

2- Temperature Sensor

3- R1

4- Joint

5- Protective cap


Chapter 3 Installation
3.1 Installation of Sensors
The specific installation steps are as follows:
a. Install the 8 (mounting plate) on the railing by the pool with 1 (M8 U-shape clamp) at the sensor mounting position;
b. Connect 9 (adapter) to 2 (DN32) PVC pipe by glue, pass the sensor cable through Pcv pipe until the sensor screws into 9 (adapter), and do waterproof treatment;
c. Fix 2 (DN32 tube) onto 8 (mounting plate) by 4 (DN42U-shape clamp).

Figure 2  Schematic Diagram on the Installation of Sensor

1-M8U-shape Clamp(DN60) 2- DN32 Pipe (outside diameter 40mm)
3- Hexagon Socket Screw M6*120 4-DN42U-shape Pipe Clip
5- M8 Gasket(8*16*1) 6- M8 Gasket(8*24*2)
7- M8 Spring Shim 8- Mounting Plate
9-Adaptor(Thread to Straight-through)

3.2 Connection of Sensor
The sensor should be correctly connected by the following definition of wire core:

Serial No. 1 2 3 4
Sensor Cable Brown Black Blue White
Signal +12VDC AGND RS485 A RS485 B

Chapter 4 Calibration of Sensor
The dissolved oxygen sensor has been calibrated at the factory,and if you need to calibrate yourself, follow the steps below
The specific steps are as follows:
①Double-click the "06", and a box pops out on the right. Change the Value to 16 and click "Send".

②Dry the sensor and put it into the air, after the measured data is stable, double-click the "06", change the Value to 19 and click "Send".

Chapter 5 Communication Protocol
The sensor is equipped with MODBUS RS485 communication function, please refer to this manual section 3.2 to check the communication wiring . The default baud rate is 9600, the specific MODBUS RTU table is shown in the following table.

Baud Rate 4800/9600/19200/38400
Data Bits 8 bit
Parity Check no
Stop Bit 1bit
Register Name AddressLocation DataType Length Read/Write Description  
Dissolved Oxygen Value 0 F(Float) 2 R(only read)   Dissolved Oxygen Value
Dissolved Oxygen Concentration 2 F 2 R   Dissolved Oxygen Concentration
Temperature 4 F 2 R   Temperature
Slope 6 F 2 W/R Range:0.5-1.5 Slope
Deviation Value 8 F 2 W/R Range:-20-20 Deviation Value
Salinity 10 F 2 W/R   Salinity
Atmospheric Pressure 12 F 2 W/R   Atmospheric Pressure
Baud Rate 16 F 2 R   Baud Rate
Slave Address 18 F 2 R Range: 1-254 Slave Address
Response Time of Read 20 F 2 R   Response Time of Read
Modift Baud Rate 16 Signed 1 W   0-48001-96002-19200



Modify Slave Address 17 Signed 1 W Range: 1-254  
Modify Response Time 30 Signed 1 W 6-60s Modify Response Time
Air Calibration Step 1 27 Signed 1 W 16
Step 2 27 Signed 1 W 19
It should be cancelled if you don’t want to calibrate after the execution of "Step 1".
Cancel 27 Signed 1 W 21
Function Code R:03
Write 06 as the reshaping data 06
Write 16 as the floating point data

Chapter 6 Maintenance
In order to obtain the best measurement results, it is very necessary to maintain the sensor regularly. Maintenance mainly includes cleaning, inspecting damage of the sensor, and periodic calibration.
6.1 Sensor Cleaning
It is recommended that the sensor should be cleaned at regular intervals (usually 3 months, depending on the site environment) to ensure the accuracy of the measurement.
Use water to clean the outer surface of the sensor. If there is still debris, wipe it with a damp soft cloth. Do not place the sensor in a direct sunlight or near radiation. In the entire life of the sensor, if the total sun exposure time reaches to one hour, it will cause the fluorescent cap aging and going wrong, and consequently leading to the wrong reading.

6.2 Inspection on the Damage of Sensor
According to the appearance of sensor to check if there is damage; if any damage is found, please contact after-sales service maintenance center in time for replacement to prevent malfunction of sensor caused by water from the damaged cap.

6.3 Preservation of Sensor
A.When you are not using it, please cover the product’s original protective cap to avoid direct sunlight or exposure. In order to protect the sensor from freezing, the DO probe should be stored in a place where it will not freeze.
B.Keep the probe clean before storing it for a long time. Keep the equipment in a shipping box or a plastic container with electric shock protection. Avoid touching it with hand or other hard objects in case of scratching the fluorescent cap.
C.It is forbidden that the fluorescent cap is exposed to direct sunlight or exposure.

6.4 Replacement of Measurement Cap
The sensor's measurement cap needs to be replaced when it’s damaged. In order to ensure the accuracy of the measurement, it is recommended to change it every year or it is necessary to be replaced when the cap is found severely damaged during the inspection.

Chapter 7 After-sales Service
If you have any questions or need repair service, please contact us as followings.

JiShen Water treatment Co., Ltd.
Add: No.2903, Building 9, C Area, Yuebei Park, Fengshou Road, Shijiazhuang, China .
Tel: 0086-(0)311-8994 7497 Fax:(0)311-8886 2036

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