SIGNUX TUR01
Water turbidity
Digital turbidity transmitter for water quality monitoring. It measures by 90-degree scattered light, with an infrared source and a fibre-optic light path; internal filtering against ambient light and automatic temperature compensation, for continuous submerged measurement. Plastic or stainless steel housing.
The SX-TUR01 is a turbidity transmitter for continuous water quality monitoring. It screws onto a waterproof pipe, stays submerged and delivers turbidity and temperature over RS485 with Modbus RTU.
Place it where the water flows slowly and without bubbles, at least 5 cm from the walls and with no obstacles within 7 cm below the sensor. It is calibrated at two points, zero and full scale, with Modbus commands. Clean it every 30 days and calibrate it every 3 months.
- Measures
- Turbidity · Temperature
- Output
- Protection
- IP68
- Operating
- 0 to +40 °C
What sets it apart
90° scattered light
Infrared light through a fibre-optic path and internal filtering: highly resistant to ambient light.
Four ranges
50, 200, 1000 or 4000 NTU. Chosen when ordering.
Temperature compensated
A built-in temperature sensor corrects the reading automatically, so the probe can stay in the water measuring continuously.
Submersible, IP68
Corrosion-resistant plastic or stainless steel housing, and five metres of cable.
Configurations
| Material / housing | Measurement range | Part number |
|---|---|---|
| Plastic | 0-50 NTU | SX-TUR01-P-50 |
| Plastic | 0-200 NTU | SX-TUR01-P-200 |
| Plastic | 0-1000 NTU | SX-TUR01-P-1000 |
| Plastic | 0-4000 NTU | SX-TUR01-P-4000 |
| Stainless steel | 0-50 NTU | SX-TUR01-S-50 |
| Stainless steel | 0-200 NTU | SX-TUR01-S-200 |
| Stainless steel | 0-1000 NTU | SX-TUR01-S-1000 |
| Stainless steel | 0-4000 NTU | SX-TUR01-S-4000 |
Specifications
General
- Measured parameters
- Turbidity · Temperature
- Output
- RS485
- Measurement principle
- 90° scattered lightInfrared LED source and fibre-optic light path
Turbidity
- Range
- 0-50 / 0-200 / 0-1000 / 0-4000 NTUChosen when ordering
- Resolution
- 0.01 NTUIn the 0.00-50.00 NTU range0.1 NTUIn the 0.0-200.0 NTU range0.1 NTUIn the 0.0-1000.0 NTU range1 NTUIn the 0-4000 NTU range
- Accuracy
- ±5 % FSAt 25 °C
- Response time
- ≤30 s
- Compensation
- AutomaticBuilt-in temperature sensor
Temperature
- Resolution
- 0.1 °C
- Accuracy
- ±0.5 °C
Output and power
- Output interface
- RS485Modbus RTU, baud rate configurable from 1200 to 115200 baud
- Protocol
- Modbus RTUFunction codes 3, 4, 6 and 16
- Power supply
- 10-30 VDC
- Power consumption
- 0.2 W
- Factory defaults
- 4800 8N1, address 1
Construction
- Protection rating
- IP68
- Operating temperature
- 0 to +40 °C
- Housing
- Corrosion-resistant plastic or stainless steelAs ordered
- Pipe connection
- NPT 3/4 threadFor mounting on a waterproof pipe
- Dimensions
- Ø30 × 134 mmPlastic housingØ30 × 144 mmStainless steel housing
- Cable length
- 5 mFour-core cable with flying leads
- Service life
- 2 yearsUnder normal use
Manual
1Introduction
The SX-TUR01 is a digital turbidity transmitter for water quality monitoring. It uses the 90° scattered light method, with an infrared LED source and a fibre-optic light path, and an internal filtering algorithm that makes it highly resistant to ambient light.
A built-in temperature sensor provides automatic temperature compensation, so the probe is suited to long-term online monitoring.
- •Turbidity measuring ranges: 0-50, 0-200, 0-1000 and 0-4000 NTU
- •IP68 protection rating
- •90° scattered light principle, highly resistant to ambient light, with automatic temperature compensation
- •RS485 interface with Modbus RTU protocol, easy to connect to a computer for monitoring
- •Configurable Modbus address and baud rate
- •Wide supply voltage range: 10-30 VDC
Specifications
| Measuring range | 0-50.00 NTU; 0-200.0 NTU; 0-1000.0 NTU; 0-4000 NTU |
| Accuracy | ±5 % FS (at 25 °C); temperature ±0.5 °C |
| Resolution | 0-50 NTU range: 0.01 NTU 0-200 and 0-1000 NTU ranges: 0.1 NTU 0-4000 NTU range: 1 NTU Temperature: 0.1 °C |
| Response time | ≤30 s |
| Operating conditions | 0-40 °C |
| Power supply | 10-30 VDC |
| Power consumption | 0.2 W |
| Communication interface | RS485, Modbus RTU 4800 baud by default (1200, 2400, 4800, 9600, 19200, 38400, 57600 and 115200 selectable) |
| Measuring principle | 90° scattered light |
| Service life | 2 years under normal use |
| Protection rating | IP68 |
| Cable length | 5 m by default |
| Housing material | Corrosion-resistant plastic or stainless steel |
2Wiring
The probe is supplied with a four-core cable with bare ends.
| Function | Wire colour | Description |
|---|---|---|
| Power supply | Brown | Power supply positive (10-30 VDC) |
| Power supply | Black | Power supply negative (GND) |
| Communication | Yellow | RS485 A |
| Communication | Blue | RS485 B |
3Dimensions and ordering information
3.1Dimensions
3.2Ordering information
| Parameter | Code | Description |
|---|---|---|
| Code 1: Product series | SX-TUR01 | Turbidity transmitter, RS485 Modbus RTU |
| Code 2: Housing | P S | Corrosion-resistant plastic Stainless steel |
| Code 3: Measuring range | 50 200 1000 4000 | 0-50 NTU 0-200 NTU 0-1000 NTU 0-4000 NTU |
| Order code example: SX-TUR01-P-200 |
| Product series: SX-TUR01 turbidity transmitter |
| Housing: corrosion-resistant plastic |
| Measuring range: 0-200 NTU |
The package contains:
- •Turbidity transmitter, 1 pc
- •5 m cable
- •Certificate and warranty card
4Safety, care and installation
4.1Installation
- •The probe has an NPT 3/4 thread for use with a waterproof pipe: route the cable through the pipe and screw the probe onto the pipe thread.
- •Install the probe where the water flows slowly and there are no bubbles.
- •Keep at least 5 cm between the probe and the surrounding walls, and no obstacles within 7 cm below the sensor.
4.2Care and maintenance
- •If the device shows an obvious fault, do not open or repair it: contact SIGNUX for a solution.
- •Remove the black rubber cap before measuring.
- •Clean the measuring probe regularly, according to the working environment: deposits cause measurement deviation. Avoid scratching the light-guide window when cleaning. Recommended cleaning interval: every 30 days.
- •Rinse the outer surface with running water. If dirt remains, wipe it with a soft, damp cloth.
- •Calibrate the probe before each use, and every 3 months in long-term use. Adjust the calibration interval to the application: how dirty the water is, chemical deposits, and so on.
5Calibration
Turbidity is calibrated at two points: zero and full scale. Both are Modbus commands on registers 0x1010 and 0x1011 (see Modbus registers).
- •Zero point: place the probe in a 0 NTU standard solution (deionized water; if high accuracy is not required, dark, clean air can be used). When the reading is stable, write 0x0001 to register 0x1010 and 0x0000 to register 0x1011.
- •Full scale: place the probe in a standard turbidity solution at the upper limit of its range. When the reading is stable, write 0x0002 to register 0x1010 and 0x0001 to register 0x1011.
- •During calibration no bubbles may cling to the optical window, and the probe must be more than 7 cm from the bottom of the container.
6Modbus RS485 protocol
6.1Communication parameters
| Encoding | 8-bit binary |
| Data bits | 8 |
| Parity | None |
| Stop bits | 1 |
| Error check | CRC (cyclic redundancy check) |
| Baud rate | 4800 bit/s by default (1200 to 115200 configurable) |
| Device address | 1 (0x01) by default |
6.2Frame format
- Communication uses the Modbus RTU protocol. Each frame is made up of:
- •Start: silence of at least 4 byte times
- •Address code: 1 byte
- •Function code: 1 byte
- •Data area: N bytes
- •Error check: 16-bit CRC
- •End: silence of at least 4 byte times
- Address code: the address of the transmitter, unique on the bus (factory default 0x01).
- Function code: the command issued by the master.
- Data area: the data of the command. In 16-bit values the high byte comes first.
- CRC: two-byte check code.
6.3Modbus registers
| Register address | Function codes (DEC) | Description |
|---|---|---|
| 0x0000 | 3 / 4 | Turbidity (NTU). UINT16: the register holds 10 times the value (100 times in the 0-50 NTU range) |
| 0x0001 | 3 / 4 | Temperature (°C). INT16: the register holds 10 times the value |
| 0x0050 | 3 / 4 / 6 / 16 | Turbidity offset. 16-bit, 10 times the value (100 times in the 0-50 NTU range); negative values in two's complement |
| 0x0051 | 3 / 4 / 6 / 16 | Temperature offset. INT16, 10 times the value |
| 0x1010 / 0x1011 | 16 | Turbidity calibration, two points: write 0x0001 to 0x1010 and 0x0000 to 0x1011 for zero; write 0x0002 to 0x1010 and 0x0001 to 0x1011 for full scale |
| 0x07D0 | 3 / 4 / 6 / 16 | Device address: 1-254 (UINT16, factory default 1) |
| 0x07D1 | 3 / 4 / 6 / 16 | Baud rate: 0 = 2400, 1 = 4800, 2 = 9600, 3 = 19200, 4 = 38400, 5 = 57600, 6 = 115200, 7 = 1200 (factory default 1 = 4800) |
- UINT16: 16-bit unsigned integer
- INT16: 16-bit signed integer
6.4Communication examples
In the following examples, values starting with 0x are hexadecimal. The two CRC bytes are sent low byte first.
6.4.1Example 1: read turbidity and temperature
Master request: 01 03 0000 0002 C4 0B
| Slave address | 1 byte | 0x01 |
| Function code | 1 byte | 0x03 |
| Start register | 2 byte | 0x0000 |
| Number of registers | 2 byte | 0x0002 |
| CRC | 2 byte | 0xC4 0x0B |
Slave response: 01 03 04 0D2E 00DB D8 CD
| Slave address | 1 byte | 0x01 |
| Function code | 1 byte | 0x03 |
| Number of data bytes | 1 byte | 0x04 |
| Turbidity | 2 byte | 0x0D2E |
| Temperature | 2 byte | 0x00DB |
| CRC | 2 byte | 0xD8 0xCD |
0x0D2E is 3374 in decimal, so the turbidity is 3374 / 10 = 337.4 NTU. 0x00DB is 219, so the temperature is 219 / 10 = 21.9 °C.
6.4.2Example 2: set the turbidity offset
To apply an offset of −10 NTU, write −100 to register 0x0050. In hexadecimal, −100 is 0xFF9C.
Master request: 01 06 0050 FF9C C8 42
| Slave address | 1 byte | 0x01 |
| Function code | 1 byte | 0x06 |
| Register | 2 byte | 0x0050 |
| Value | 2 byte | 0xFF9C |
| CRC | 2 byte | 0xC8 0x42 |
The slave replies with the same frame, as the Modbus standard defines for this function.
Slave response: 01 06 0050 FF9C C8 42
| Slave address | 1 byte | 0x01 |
| Function code | 1 byte | 0x06 |
| Register | 2 byte | 0x0050 |
| Value | 2 byte | 0xFF9C |
| CRC | 2 byte | 0xC8 0x42 |
6.4.3Example 3: calibrate the full scale point
With the probe stable in a standard solution at the upper limit of its range, write 0x0002 to register 0x1010 and 0x0001 to register 0x1011 in a single command.
Master request: 01 10 1010 0002 04 0002 0001 5F 63
| Slave address | 1 byte | 0x01 |
| Function code | 1 byte | 0x10 |
| Start register | 2 byte | 0x1010 |
| Number of registers | 2 byte | 0x0002 |
| Number of data bytes | 1 byte | 0x04 |
| Values | 4 byte | 0x0002, 0x0001 |
| CRC | 2 byte | 0x5F 0x63 |
Slave response: 01 10 1010 0002 44 CD
| Slave address | 1 byte | 0x01 |
| Function code | 1 byte | 0x10 |
| Start register | 2 byte | 0x1010 |
| Number of registers | 2 byte | 0x0002 |
| CRC | 2 byte | 0x44 0xCD |
Gallery
Documentation
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