SIGNUX TUR01
It sees what clouds the water before you do
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.
- Measures
- Turbidity · Temperature
- Output
- Protection
- IP68
- Operating
- 0 to +40 °C
What sets it apart
90° scattered light
The standard method for turbidity. With internal filtering and a fibre-optic light path, ambient light does not affect the reading.
Four ranges
From 50 to 4000 NTU. Chosen when ordering: a 50 NTU unit cannot measure a thousand, and it is not reconfigured afterwards.
Temperature compensated
A built-in temperature sensor corrects the reading automatically, so the probe can stay in the water measuring continuously.
Waterproof, 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 NTUSet when ordering; not reconfigurable
- 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 0.0-4000.0 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 PLC, datalogger or computer
- •Configurable Modbus address and baud rate
- •Wide supply voltage range: 10-30 V DC
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 V DC |
| 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 V DC) |
| 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.
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 |
6.4.3Example 3: calibrate the full scale point
After the value is stable in the 0 turbidity environment, writes 0x0001 to the 0x1010 register, and writes 0x0000 to the 0x1011 register. When calibrating the full scale point,should select the standard turbidity liquid at the upper scale limit, write 0x0002 to 0x1010 and 0x0001 to 0x1011.
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 |
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Documentation
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