Low Conductivity Probe AT-SB-PROBE-LC-P-C1
Datasheet
1. Introduction
SENSBLUE RS‑485 Conductivity Probe AT‑SB‑PROBE‑C‑P features a wide measurement range with automatic range switching, integrating a built‑in temperature sensor that enables continuous real‑time temperature compensation.
Excellent resistance to pollution even in harsh environments. Long term online monitoring will show no polarization. RS‑485 output can be networked without a controller.
2. Features
- Drinking water / surface water / industrial water treatment;
- Signal output: RS-485 (Modbus/RTU protocol);
- Convenient connection to third‑party equipment such as PLCs, DCS, industrial control computers, general controllers, paperless recorders, or touch screens;
- Immersion installation with 3/4 NPT pipe thread, suitable for immersion or installation in pipelines and tanks;
- IP68 protection.
3. Technical Specifications
| Product | Conductivity Sensor | ||
|---|---|---|---|
| Model | LC | MC | HC |
| Measuring Range | 0 – 20 μS/cm | 0 – 200 μS/cm | 0 – 5000 μS/cm |
| Accuracy | 1.5% F.S. | ||
| Response time | <10 sec | ||
| Ip Grade | IP68 | ||
| Maximum Operating Pressure | 6 bar | ||
| Temperature Range | 0~50℃ | ||
| Output | RS-485, MODBUS protocol | ||
| Power Supply | 12～24VDC±10% | ||
| Temperature Compensation | Automatic | ||
| Wetted Part Material | ABS / SUS316L / PVC | ||
| Sensor size | Φ 30*185 mm | ||
| Cable Length | Standard 5m, other length customizable | ||
| Calibration Method | Two-point calibration | ||
4. Dimensions and Wiring
KWS-350 (Range: 0~20.00μS/cm)
KWS-350 (Range: 0~200.0μS/cm)
KWS-350 (Range: 0~5000μS/cm)
| Pinouts | |
|---|---|
| 1 - Pin 12-24V DC | 4 - RS485 B- |
| 2 - GND | 5 – NA |
| 3 - RS485 A+ | 6 - NA |
| 7 - NA | |
5. Installation and Electrical Connection
Installation
The sensor needs to be installed below the liquid level. The installation and use should avoid any collisions or scraping against the surface of the fluorescent film head. The fluorescent film head should also be kept from contacting the bottom sediment. Remove the rubber cover when in use.
6. Maintenance
6.1 User and maintenance
Conventional electrodes need to be cleaned and calibrated periodically, and the maintenance interval is determined by the customer according to their operating conditions. The standard cleaning method is to use a soft brush to remove any attachments (being careful not to scratch the electrode surface), then rinse with distilled water, and perform the calibration procedure.
6.2 Calibration
a) Zero calibration: Rinse the sensor with distilled water and blot the liquid with filter paper. Connect the sensor to the power, place it upright in the air, and let it stand for about 3 minutes. After the value becomes stable, perform the zero‑point calibration. Refer to the appendix for details on the calibration instructions.
b) Slope calibration: Place the electrode vertically in the standard solution (20% full scale), ensure that the electrode is at least 2 cm away from the bottom and side walls of the container, and perform the slope calibration. Refer to the appendix for details of the calibration instructions.
7. Appendix data communication
7.1 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 the baud rate can be customized.
7.2 Information Frame Format
a) Read data instruction frame
06 03 xx xx xx xx xx xx
Address Function code Register address Number of registers. CRC check code (low byte first)
b) Read data response frame
06 03 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 xx xx xx xx xx xx
Address Function code. Register address. Write data. CRC check code (low byte first)
7.3 Register Address
| Register address | Name | Explain | Number of registers | Access Mode |
| 40001 (0x0000) | Measured Value + Temperature | Four double‑byte integers are measured: the value, its decimal places, the temperature value, and the temperature decimal places. | 4（8byte) | Read |
| 44097 (0x1000) | Zero Calibration | Calibrate in the air, write data as 0 | 1（2byte) | Write |
| 44101 (0x1004) | Slope Calibration | Calibrate in a known standard solution (20%–full scale). The written data is the actual value of the standard solution. | 1（2byte) | Write |
| 44103
(0x1006) |
Zero-point calibration value | The read value represents the zero offset. | 1（2byte) | Read |
| 44105
(0x1008) |
Slope
calibration Value |
The read data is the slope value×1000. | 1（2byte） | Read |
| 44113
(0x1010) |
temperature
Correction |
In solution, the value written is the actual temperature ×10. The read value is the temperature calibration offset ×10. | 1（2byte) | Write / read |
| 48195
(0x2002) |
Sensor
Address |
The default is 6, and the write data
range is 1 ≤ 127. |
1（2byte) | Write / read |
| 48225
(0x2020) |
Reset sensor | Restores calibration values to default. Write value 0. After reset, the sensor must be recalibrated. | 1（2byte) | Write |
Note: Register address is the register start address with register type defined according to Modbus protocol (the actual register start address represented by hexadecimal in parentheses). When you change the sensor address, the sensor address in the return instruction is the changed new address. The data definition that returns the measured value when reading the data:
xx xx xx xx xx xx xx xx
2 bytes measured value Number of decimal places of 2 bytes measured 2 bytes temperature value 2-byte temperature decimal places. The data type defaults to a double-byte integer, with high bytes in front of it; others, such as floating- point types, are optional.
7.4 Command Example
a) Start measurement command
Function: Get the conductivity and temperature measured by the sensor; the unit of temperature is degrees Celsius, and the unit of conductivity is US/cm;
Request frame：01 03 00 00 00 04 44 09
Response frame：01 03 0C 01 02 00 01 00 B0 00 01 00A5 00 01 35 73
Example of reading:
| Temperature scale | Conductivity value | TDS value |
| 00 B0 00 01 | 01 02 00 01 | 00 A5 00 00 |
For example:
- Conductivity value 01 02 represents the hexadecimal reading of the conductivity value, and 00 00 indicates that the conductivity value has no decimal point (the number of decimal places depends on the range), resulting in a decimal value of 258.
- Temperature value 00 B0 represents the hexadecimal reading of the temperature value, and 00 01 indicates that the temperature value has 1 decimal place, resulting in a decimal value of 17.6.
- TDSvalue00A5indicates the TDS value in hexadecimal reading, 00 00 indicates the temperature value without decimal point, and the decimal value is 165.
b) Calibration instruction
Zero-point calibration
Function: Set the zero-point calibration value of the conductivity of the sensor here the zero-point calibration is carried out in the air:
Request frame：01 06 10 00 00 00 8D 0A
Response frame ：01 06 10 00 00 00 8D 0A
Slope calibration
Set the conductivity slope calibration value of the sensor; here the slope value is based on the actual standard solution value, taking 5000uS/cm as an example for reference calibration:
Request frame： 01 06 10 04 01 F4 CC DC
Response frame：01 06 10 04 01 F4 CC DC
c) Set the device address
Function: set the Modbus device address of the electrode; Change the device address 06 to 01, with the following:
Response frame: 01 06 20 02 00 06A3 C8
Request frame: 01 06 20 02 00 06A3 C8
7.5 Error Response
If the sensor does not execute the host command correctly, it will return the following format information:
| Definition | Address | Function code | CODE | CRC Check |
| Data | ADDR | COM+80H | xx | CRC 16 |
| Number of bytes | 1 | 1 | 1 | 2 |
a) CODE:
01 – function code error
03 – data error
b) COM: Received function
8. Applicable Accessories
| Name | Requirements | |
| PA000000076 | SENSBLUE MONARCH Solar Panel 1 Probe | |
| PA000000079 | SENSBLUE MONARCH Solar Panel 2 Probes | |
| PA000000080 | SENSBLUE MONARCH Solar Panel 1 Probe External Antenna | |
| PA000000074 | SENSBLUE MONARCH Solar Panel 2 Probes External Antenna | |
| PA000000081 | SENSBLUE MONARCH Opaque Case 1 Probe | |
| PA000000082 | SENSBLUE MONARCH Opaque Case 2 Probes | |
| PA000000083 | SENSBLUE MONARCH Opaque Case 1 Probe External Antenna | |
| PA000000084 | SENSBLUE MONARCH Opaque Case 2 Probes External Antenna | |
| PA000000020 | SENSBLUE MONARCH RS485 Probe Splitter Box (1 input -> 2 outputs) |
9. Similar Products
| Name | Requirements | |
| PA000000085 | SENSBLUE RS-485 Dissolved Oxygen Probe AT-SB-PROBE-DO-T-C1, w/ 15m cable w/connector | |
| PA000000086 | SENSBLUE RS-485 Low Conductivity Probe AT-SB-PROBE-LC-P-C1, w/ 15m cable w/connector | |
| PA000000087 | SENSBLUE RS-485 Medium Conductivity Probe AT-SB-PROBE-MC-P-C1, w/ 15m cable w/connector | |
| PA000000088 | SENSBLUE RS-485 ORP Probe AT-SB-PROBE-ORP-P-C1, w/ 15m cable w/connector | |
| PA000000089 | SENSBLUE RS-485 Salinity/Conductivity/TDS Probe AT-SB-PROBE-S-P-C1, w/ 15m cable w/connector | |
| PA000000090 | SENSBLUE RS-485 Ammonia Nitrogen (NH4-N) Sensor Probe AT-SB-PROBE-NH4-P-C1, w/ 15m cable w/connector | |
| PA000000091 | SENSBLUE RS-485 Dissolved CO2 Sensor Probe AT-SB-PROBE-CO2-P-5000-C1, w/ 15m cable w/connector |
10. Applicable certifications and standards
EMC Directive 2014/30/EU.
- EN IEC 61326-1: 2021
- EN 55011: 2016+A2: 2021
- EN IEC 61000-3-2: 2019+A1: 2021
- EN 61000-3-3: 2013+A2: 2021