Multiparameter Probe AT-SB-PROBE-MP-P-C1

Datasheet

1. Introduction

The SENSBLUE RS‑485 Multiparameter Probe AT‑SB‑PROBE‑MP‑P is an online multiparameter self‑cleaning digital sensor introduced by the company. It adopts an integrated design, and the product is reliable and easy to use. Up to 8 parameters can be measured at the same time, with optional sensor types such as dissolved oxygen, COD, pH, ORP, conductivity/salinity, ammonia nitrogen, turbidity, etc. Using the RS‑485 bus and Modbus/RTU communication protocol, data can be directly transmitted to the acquisition platform.

The online multiparameter water quality sensor is equipped with an automatic cleaning device that allows setting the automatic cleaning interval and the number of cleaning cycles to match different water quality conditions. The automatic cleaning device can effectively clean the sensor surface, prevent microorganism adhesion, and greatly reduce maintenance costs. Each sensor is equipped with a quick‑plug waterproof connector, making assembly and disassembly easy. The front sensor protection cover prevents damage to the internal sensor. Slots around the protection cover effectively block large suspended particles and organisms from damaging the probe while maintaining measurement accuracy.

2. Features

Digital sensor with RS‑485 bus and Modbus/RTU communication protocol.
Equipped with an automatic cleaning device that effectively cleans the sensor surface, prevents microorganism attachment, ensures more accurate measurements, and reduces maintenance costs.
Optional digital sensors such as dissolved oxygen, COD, conductivity/salinity, turbidity, ammonia nitrogen, pH, ORP, etc., suitable for long‑term online monitoring.
Integrated design capable of measuring 8 parameters (including temperature) simultaneously.

3. Technical Specifications

Dissolved Oxygen Probe
Measuring Range	0～20mg/L
Accuracy	±0.4mg/L
Resolution	0.01mg/L
Turbidity Probe
Measuring range and Accuracy	0～100NTU	±3% or ±2NTU
Measuring range and Accuracy	0～1000NTU	±5% or ±3NTU
Resolution	0.1NTU
Conductivity / Salinity Probe
Measuring range	0～5000uS/cm	1uS/cm
Resolution	0～200mS/cm	0.1mS/cm
Resolution	0～70PSU	0.1PSU
Accuracy	±1.5% F.S.
COD Probe
Measuring range	COD	Turbidity
	0～200mg/L equiv. KHP	0～100NTU
	0～500mg/L equiv. KHP	0～200NTU
COD accuracy	±5% F.S.
COD resolution	0.1mg/L
Turbidity accuracy	±5% F.S.
Turbidity resolution	0.1NTU
pH Probe
Measuring range	0～14pH
Accuracy	±0.1pH
Resolution	0.01pH
ORP Probe
Measuring range	-1500mV～+1500mV
Accuracy	±10% or ±2mg/L
Resolution	0.1mg/L
Temperature
Measuring range	0～50℃
Accuracy	±0.5℃
Resolution	0.1℃
Other Information of Multi-parameter Probe
Output	RS-485 (Modbus/RTU)
Cleaning method	Automatic cleaning
Power consumption	5W @ 12V
Power supply	12VDC ±5%
Cable length	5 meters, other lengths can be customized
Chlorophyll

4. Dimensions and Wiring

Note: When the sensor is installed for measurement, use lifting rings or pipe thread installation to avoid direct force on the cable. The sensor connector is M16-5 core waterproof male connector.

Pinouts
1 - NA	4 - RS485 B-
2 - GND	5 – NA
3 - RS485 A+	6 - Pin +12V DC
7 - NA

5. Maintenance Schedule

SENSBLUE RS-485 Multiparameter Probe AT-SB-PROBEMP-P is equipped with a cleaning brush, which can extend the maintenance cycle. However, due to the diversity of the environment, it is recommended to inspect, clean and calibrate the sensors regularly.

Maintenance Task	Recommended Maintenance Frequency
Clean the sensor	According to the use environment
Calibrate the sensor (if required by the competent authority)	Periodic one- or two-point calibration

5.1 Maintenance Methods

1.Inspection:

Check whether the sensor´s head is dirty and microorganisms are attached, whether the housing and sensor surface are damaged, whether the cable is normal, whether the test data is normal, and whether the consumables are damaged.

2. Cleaning:

Clean the outer surface of the sensor with tap water. If debris remains, wipe it with a moist soft cloth. For stubborn dirt, you may add some household detergent to the tap water.

3.Calibration:

Perform single‑point or two‑point calibration of the sensor. Select the appropriate standard solution according to the corresponding sensor.

5.2 Matters Needing Attention

The probe contains sensitive optical and electronic components. Make sure the probe is not subjected to severe mechanical shock. There are no parts inside the probe that require user maintenance.

6. Modbus Protocol

6.1 Data Format

The default data format for Modbus communication is: 9600, n, 8, 1 (baud rate 9600 bps, 1 start bit, 8 data bits, no parity, 1 stop bit).

Parameters such as baud rate can be customized.

6.2 Information Frame Format

a) Read data instruction frame

06 03 xx xx xx xx xx xx

Address Function code Register start address Number of registers CRC check code (low byte first)

b) Read data response frame

06 03 xx xx xx xx xx xx

Address Function code Bytes Answer data CRC check code (low byte first)

c) Write data instruction frame

06 06 xx xx xx xx xx xx

Address Function code Register address Write data CRC check code (low byte first)

d) Write data response frame (same data command frame)

06 06 xx xx xx xx xx xx

Address Function code Register ddress Write data CRC check code (low byte first)

6.3 Register Address

0x0006	Conductivity / salinity value	2 double-byte integers, respectively conductivity / salinity value and the number of decimal places for the conductivity / salinity value.	2 (4 bytes)	Read (0x03)
0x0008	pH value	2 double-byte integers, respectively pH value and the number of decimal places for the pH value.	2 (4 bytes)	Read (0x03)
0x000A	ORP value	2 double-byte integers, respectively ORP value and the number of decimal places for the ORP value.	2 (4 bytes)	Read (0x03)
0x000C	DO value	2 double-byte integers, respectively DO value and the number of decimal places for the DO value.	2 (4 bytes)	Read (0x03)
0x0010	Turbidity value	2 double-byte integers, respectively turbidity value and the number of decimal places for the turbidity value.	2 (4 bytes)	Read (0x03)
0x0020	Chlorophyll	2×16-bit integers: chlorophyll value + decimal digits	2 (4 bytes)	Read (0x03)

0x1000	Temperature calibration	Temperature calibration: The write data is the actual temperature value x10; the read data is the temperature calibration offset x10.	1 (2 bytes)	Write (0x06) (0x03) Read (0x03)
0x1002	COD zero calibration	Calibrated in deionized water. The calibration value written during calibration is 0. The read‑out data is the original COD zero‑point signal. For the 0–200 mg/L measuring range, calibration can be performed in 0–20 mg/L COD standard solutions, and the written value during calibration is the standard solution ×10.For the 0–500 mg/L measuring range, calibration can be performed in 0–50 mg/L COD standard solutions, and the written value during calibration is the standard solution ×10.	1(2bytes)	Write (0x06) (0x03) Read (0x03)
0x1003	COD slope calibration	For the 0–200 mg/L measuring range, calibration can be performed in 20–200 mg/L standard solutions. The written value during calibration is the standard solution value ×10, and the read‑out value is the original COD slope signal. For the 0–500 mg/L range, calibration can be performed in 50–500 mg/L standard solutions, with the written value being the standard solution ×10 and the read‑out value the slope original signal.	1(2bytes)	Write (0x06) (0x03) Read (0x03)
0x1004	COD built-in zero turbidity calibration	Calibrated in deionized water, with written data set to 0. The read‑out data is the zero offset.	1(2bytes)	Write (0x06) (0x03) Read (0x03)
0x1005	COD built-in turbidity slope calibration	Calibrated using a 20.0–200.0 NTU turbidity standard solution. The written data is the turbidity value of the standard solution ×10, and the read‑out data is the slope value ×1000.	1(2bytes)	Write (0x06) (0x03) Read (0x03),

0x1002	COD zero calibration	Calibrated in air; the write data is 0, and the read data is the zero offset.	1(2bytes)	Write (0x06)/ Read (0x03)
0x1007	Slope calibration of conductivity / salinity	Calibration is performed in a standard solution. For the 0–5000 μS/cm full scale, the write data is the actual value of the standard solution. For the 0–200 mS/cm full scale, the write data is the actual value of the standard solution ×10.For the 0–70 PSU full scale, the write data is the actual value of the standard solution ×10.The read data is the slope value ×1000.	1(2bytes)	Write (0x06)/ Read (0x03)
0x1008	Zero calibration of pH	Calibrated in a standard solution with a pH of 6.86; the write data is 0, and the read data is the zero offset.	1(2bytes)	Write (0x06)/ (0x03)
0x1009	Slope calibration of pH (4pH/9pH)	Calibrated in a standard solution with pH 4.00, where the write data is 0.Calibrated in a standard solution with pH 9.18, where the write data is 1.The read‑out data is the slope value ×1000.	1(2bytes)	Write (0x06)/Read (0x03)

0x100A	Zero calibration of ORP	Calibrated in the standard solution; the write data is the actual value, and the read data is the zero offset.	1(2bytes)	Write (0x06)/ Read (0x03)
0x100B	Slope calibration of ORP	Calibrate in the standard solution and write the data as the standard conductivity value; the read data is the slope value ×1000.	1(2bytes)	Write (0x06)/ Read (0x03)
0x100C	Zero calibration of DO	Calibrated in oxygen‑free water; the write data is 0, and the read data is the zero offset.	1(2bytes)	Write (0x06)/ Read (0x03)
0x100E	Zero calibration of NH	Calibration can be performed in a 1 ppm or 10 ppm solution, and the calibration data written during calibration is the value of the standard solution concentration ×10. The read‑out data is the mV value ×100 corresponding to the zero‑calibration value.	1(2bytes)	Write (0x06)/ Read (0x03)

0x100F	Slope calibration of NH +	Calibration can be performed in a 10 ppm or 100 ppm solution. The calibration value written during the procedure is the standard solution concentration ×10. The read‑out data is the mV value ×100 corresponding to the slope‑calibration value. Note that the concentration of the slope standard should be 10 times the concentration of the zero‑calibration standard.	1(2bytes)	Write (0x06)/ Read (0x03)
0x1010	Zero-calibration of turbidity	Calibration is performed in deionized water or a 0–20.0 NTU standard solution. The written data is the turbidity value of the standard solution ×10, and the read‑out data is the zero offset.	1(2bytes)	Write (0x06)/ Read (0x03)
0x1011	Slope calibration of turbidity	Calibrated using the turbidity standard solution; the written data is the turbidity value ×10 of the standard solution, and the read‑out data is the slope value ×1000.	1(2bytes)	Write (0x06)/ Read (0x03)
0x1020	Chlorophyll Zero	Calibrate in DI water; write 0; read offset	1 (2 bytes)	Write (0x06) / Read (0x03)
0x1021	Chlorophyll Slope	Calibrate in 200–400 μg/L standard solution; write = turbidity ×10; read slope ×1000	1 (2 bytes)	Write (0x06) / Read (0x03)

0x1300	Automatic cleaning Interval Setting	The default value is 30 minutes, and the data range is 6 to 6000 minutes.	1(2bytes)	Write (0x06)/ Read (0x03)
0x1301	Automatic cleaning lap setting	The default value is 3 laps, and the data range is 0 to 10 laps.	1(2bytes)	Write (0x06)/ Read (0x03)
0x2000	The address of the sub-sensor corresponds to the temperature data	The default value is 4, and it can be set to 1, 4, 8, 32, 64, 65, and so on.	1(2bytes)	Write (0x06)/ Read (0x03
0x2002	Sensor address	The default address is 6, with a valid range from 1 to 127.	1(2bytes)	Write (0x06)/ Read (0x03)
0x2020	Reset	The written data must be 0. This command restores factory settings for the automatic cleaning interval, number of cleaning cycles, and other related parameters.	1(2bytes)	Write (0x06)