The ARGES Turbidity Sensor by Keynes Controls is a single-channel instrument that can detect and report turbidity levels in the range of 0.5 - 2000 NTU. The ARGES Turbidity Sensor has been designed to be used as a stand-alone laboratory instrument, as part of a multi-parameter device inside a Keynes Controls SONDE, and can be connected directly into a plant-wide SCADA system using the MODBUS protocol.
All of the Keynes Controls manufactured fluorometers supply measurements directly in engineering units. The stainless steel construction enables the sensors to be long-term deployed for remote applications.
The turbidity sensor optics should be cleaned before a new measurement using the ARGES Brush interface. The ARGES Brush unit can be fitted into any of the multi-parameter housings.
Measurement Integrity
All of the ARGEs sensor range have the serial numbers and the last calibration date stored internally. The user can access this information for reporting purposes. The sensors can be redeployed at any time with the calibration and serial number records are retained in the sensor.
Further Information
| Turbidity 4 | NTU Water at the Consumers’ taps | --- | UK DWI Drinking Water Standard |
| 0 - 0.318 | NTU | --- | Distilled Water |
| <10 | NTU | --- | Fresh Water |
| >100 | NTU | --- | Unsafe for most aquatic life |
To provide a sense of scale, water with a turbidity of 1 NTU is crystal clear, water at 5 NTU has a tiny trace of discolouration, and water at 100 NTU is brown and opaque. The standard is less than 10 NTU for rural streams and rivers and less than 30 NTU for urban lakes and ponds.
Applications Software
The ARGES Turbidity Sensor by Keynes Controls is supplied with a copy of the Keynes Controls Q-LOG application software.
Our Q-LOG software runs on the widely recognised Windows Operating system. You have the ability to calibrate, adjust instrument network address, and effortlessly display measurements on a series of panel meters and charts. Conveniently store results in text based files for quick analysis in spreadsheets.
The Q-LOG software can be used to test a single, or multiparameter system prior to its deployment, be that as a stand-alone solution.
In-situ measurement, no sampling, no reagents
• Direct SI Unit output of parameters
• Optical window with coating to minimize clogging
• Real time measurement
• Automatic compensation for temperature effects
Measurements
The ARGES Turbidity sensor can be used as a stand-alone device or as a part of a multiparameter solution. For stand-alone operations simply connect the sensor to a media converter and make measurements. The industry standard SDI12 commands are used to configure, calibrate and make measurements.
The instrument connects directly to SDI12 , RS485 and MODBUS networks.
The ARGES Turbidity Sensor by Keynes Controls can be used as a stand-alone device or as a part of a multiparameter solution. Keynes Controls currently manufacture 7 port and 3 port sensor housings. An optional submersible brush unit is available for cleaning the instrument optics for use in long term deployments.
Calibration Period
All of the sensors are factory-calibrated before shipment. The advanced design of the sensors means that the time between re-calibration of an instrument is minimised. Keynes Controls recommends a check calibration every 2 years. The user can adjust the calibration for a specified range to improve accuracy for dedicated tasks. A range of calibration solutions manufactured by Keynes Controls are available from the online shop.
There are two standard units for reporting turbidity - Formazin Nephelometric Units (FNU) and Nephelometric Turbidity Units (NTU). The ARGES Turbidity Sensor by Keynes Controls is set to use NTU by default.
Improved Results
The ARGES Turbidity Sensor by Keynes Controls is an intelligent sensor and stores calibration factors internally. The sensor can be re-calibrated over a smaller restricted range if the samples are under investigation are know to be of a limited range.
Optional Accessories
Keynes Controls manufactures a range of accessories that can be used with the ARGES range of chemical sensors.
A range of USB-media converters can be used to connect individual as well as multi-parameter housings to a Windows operating system computer. Free Applications Software is available for sensor configuration and making measurements.
The ARGES Brush mechanism can be individually controlled to make multiple cleaning operations for the fluorometer optics.
Additionally, the sensors can be secured into the SONDE housing and locked into place. A locking nut secures the sensor to the housing base unit. A protective shade cap screws into the base of the unit and is used to prevent stray light for affecting the optical measurements. The shade cap also protects the sensing elements from damage. Eyelets can be screwed into the top of the SONDE housing to enable securing cables to be used to lower and secure the instruments into place.
Product Features
| TYPE | RANGE (Typical levels) |
| Solid state ISE sensor | |
| Concentration range: | 0 to 2000 NTU - Other ranges on request. |
| Resolution: | 0.01 NTU |
| Accuracy: | +/- 2 % of reading. +/- 0.5 NTU which ever is greater |
| Stand-alone and SONDE Multi-parameter operations |
|
| Calibration Period | Approximately 2 years, depending on usage. |
| pH Range | 0 - 14 |
| Operation | Photometric |
| Digital Communications | SDI12 / RS485 / MODBUS Digital Communications |
| Depth | 200 m |
| Simple Calibration | Multi-point Calibration Point Optional |
| SI Units |
NTU / Degree C - other turbidity units on request |
| Analogue Output |
0-2 V DC - proportional to concentration |
Sensor Deployment
The ARGES Turbidity Sensor by Keynes Controls can be installed into any of the SONDE ports and used in collaboration with any of the other supported sensors. A network connection is made using the waterproof connector. This is the same connector that is used in the SONDE as is used on the individual sensors themselves.
Once the sensor is enclosed in the SONDE housing unit, the sensor is ready for effortless deployment into the water, providing precise measurements to the connected devices.
For long term applications where any of the ARGES fluorometer sensors are being used within water then a submersible brush unit should be used to clean the sensor optics before a measurement is taken. Any contamination of the optics due to debris in the water source can affect the results.
Deployment example:
Specifications
| ENVIRONMENTAL CHARACTERISTICS | ||||
| Turbidity | MDL 0.5 NTU | Range 0 - 2000 NTU | ||
| Other ranges by request. | Ambient Range: 0 - 50 Degree Celsius | |||
| Water Temperature: 2 to 60 Degree Celsius | ||||
| Precision | 0.01 NTU | |||
| PHYSICAL DIMENSIONS | ||||
| Length x Diameter: 22 x 205 mm | ||||
| Response |
|
Weight: 180 g | ||
| Wiper Trigger | SDI12 Command | aM! - measurement starts scan | Maximum Depth : 50 m | |
| Excitation | UV | Built-in Network Types: | ||
| Housing | 316 Stainless Steel | MODBUS / SDI12 / RS485 | ||
| Focal Point | 1 cm In-front of sensor faceplate | |||
| Data Output | SI Units, Degree Celsius | Supply Voltage: 10 - 18 V DC Standby Current 2 mA |
Supported Commands
| Most commonly used commands | ||
| Description | Master | Sensor Response |
| Send ID | aI! | a13KEYNESVWRDOA001\r\n |
| Address Query | ?! | a\r\n where a = Address |
| Start Measurement | aM! where a = Address | a0261\r\n |
| Concurrent Measurement: | aC! where a = Address | a0261\r\n |
| Get Measurement | aD! where a = Address | a+Turbidity (NTU)+Temp (Degree Celsius) |
| Read Serial Number | aXSN! | Instrument Response a+Serial-number |
| Calibration Date | aXCD! | Instrument Response a+date |
Built-in Communication Options
The ARGES Turbidity Sensor by Keynes Controls supports SDI-12, RS485 and MODBUS digital communications as standard, enabling the sensors to be directly connected to data logger for remote web based reporting, onto Wi-Fi and Local Area Networks using the RS485 option, and directly into SCADA applications using the MODBUS.
MODBUS Operations
WARNING:
Favourable measurements made by this equipment do not guarantee that a water sample is safe for human or animal consumption. The ARGES Intelligent Submersible Fluorometer sensors can not detect the presence of harmful bacteria or toxins. If in doubt, ALWAYS TREAT SUSPECT WATER PRIOR TO CONSUMPTION.