ARGES Nitrate Sensor
The ARGES Nitrate Sensor by Keynes Controls, is a submersible sensor that has been designed to simplify the acquisition of water quality measurement parameters into any platform that supports real-time reporting, data logging operations.
The Intelligent Submersible Nitrate Sensor measures the charged nitrate ions in the water.
The ARGES Nitrate sensor can be used stand-alone, or be installed into a ARGES Multiparameter SONDE.
The ARGES Nitrate Sensor by Keynes Controls directly supports SDI12, RS485 and MODBUS digital networks.
Measurement Integrity
All of the ARGEs sensor range have the serial number 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.
Product Features
| TYPE | RANGE (Typical levels) |
| Solid state ISE sensor. | |
| Measurement range: | 1.0 - 62000 mg/L / 1x10-5 to 1x10-1 Mol / 1 to 62000 ppm - Auto-ranging |
| Nitrate Resolution: | 0.01 ppm |
| Nitrate Accuracy: | +/- 10% of Reading |
| Built-in Digital Networks |
SDI12 / RS485 / MODBUS (16 & 32 Bit Registers) |
| Sensor life: | Re-calibrate after 5000 hours (3 months) |
| pH Range | 2-11 |
| Isolated Electrodes | Between measurements / standby mode. |
| Sensor Element | Solid State |
| Interference IONS | CIO4-, CIO5-,I-, CN-, BF4- |
| SI Units | ppm Degree Celsius |
ISOLATION
The sensor element of the Nitrate Sensor is isolated when not required to make a measurements. This reduces contamination of the sensor element and maintains the long active life of the device.
When no measurement is being made the sensor is in low power mode.
Calibration Summary
Keynes Controls offer a calibration kit for The Intelligent Submersible Nitrate Sensor and this is available from the online store.
The ARGES Nitrate Sensor is typically calibrated at 2 points. A zero point which uses distilled water, and the high end calibration point using one of the calibration standard solutions.
The overall accuracy of the sensor will depend upon how well the sensor is calibrated. For optimum results calibrate the sensor at the same temperature of the solution under test.
The QLOG applications software gives the user the ability to write calibration settings into the sensor.
Storage and Handling
When not in use the ARGES Nitrate Sensor by Keynes Controls can be stored dry for a long period of time without any degradation in performance. Should the sensor not be used for a considerable length of time then soak the sensor in a low Nitrate concentration solution for several hours before use.
Storage temperature range : -2 to 60 Degrees Celsius.
Further Information
The majority of nitrate in groundwater in the UK is derived from diffuse pollution from agriculture, with the rest from sewage sludge disposal to land, atmospheric deposition and point sources.
Nitrate levels in our water resources have increased in many areas due to applications of inorganic fertiliser and animal manure in agricultural areas. The regulatory limit for nitrate in public drinking water supplies was set to protect against infant methemoglobinemia, but other health effects have not been considered.
Application Uses
- Natural water
- Surface Water
- Ground water
- Produced Water
- Water Purification
Monitoring applications.
Product Specifications
| DISSOLVED Nitrate | ENVIRONMENTAL CHARACTERISTICS | |||
| Range | 1 - 62000 ppm | Storage Range: -6 to 55 Degree Celsius | ||
| Resolution | 0.01 ppm | Ambient Range: 0 - 50 Degree Celsius | ||
| Accuracy | 10 % Reading | Water Temperature: 1 to 40 Degree Celsius | ||
| Maximum Depth: 50 m | ||||
| Process Electrodes: | Solid State | |||
| PHYSICAL DIMENSIONS | ||||
| Length x Diameter: 22 x 220 mm | ||||
| Weight: 97 g | ||||
| Settling Time |
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| Wiper Trigger | SDI12 Command | aM! | ||
| Built-in Network Types: | ||||
| Excitation | Potentiometric | SDI12 / RS485 / MODBUS over 485 | ||
| Housing | PVC / Stainless steel 316 | |||
| Sensor Connector | Gold Plated | Power Requirement | ||
| Voltage Range: 10-18 V DC | ||||
| Data Output | - PPM Deg C | Standby Current: 0.9 mA Typical | ||
| Reading: 25 mA for 1 Sec - Typical |
Please Note: The ARGES Nitrate sensor is pre-calibrated at the factory.
Supported Commands
Most Used Commands - SDI12
| Description | Master | Instrument Response |
| Start measurement | aM! | a05\r\n where 05 = time delay before measurement sent |
| Send ID | al! | a14KEYNESCOISO000014\r\n Part description assigned by Keynes |
| Address Query | ?! | Where a = ID number - 0 - 9 (standard) / (a..z) Enhanced SDI-12 0 - 9 / a - z for RS485 |
| Change Address | aAb! | where a = Initial address and b = Final address |
| Start Measurement | aM! | Make a measurement - a = address of sensor Example 1M! starts a measurement for sensor with ID=1 |
| Concurrent measurement: Used for starting a measurement for all the sensors in a SONDE or on a digital network. |
aC! | Start a measurement for sensor on address 'a'. |
| Read Serial Number | aXSN! | Instrument Response a+Serial-number |
| Calibration Date | aXCD! | Instrument Response a+date |
Commonly used with: Ammonia, pH, Tryptophan CDOM Sensors.
The Submersible ARGES Nitrate Sensor by Keynes Controls monitors the amount of charges nitrate ions in water. The ARGES Nitrate Sensor readings can be affected by changes in temperature and ionic activity. This sensor is frequently paired with CDOM, pH, and other chemical sensors crafted and produced by Keynes Controls.
Submersible pH Sensor = The Intelligent Submersible pH Sensor by Keynes Controls, is a high performance submersible sensor that has been designed to simplify the acquisition of water quality measurement parameters into any platform that supports data logging operations using digital network communications. Read More...
Built-in Communication Options
The ARGES Nitrate Sensor supports SDI12, RS485 and MODBUS digital communications as standard enabling it to be directly connected to Data Logger for remote web based reporting, onto Wi-Fi and Local Area Networks using the RS485 option. The MODBUS and RS485 option are often used to connect sensors to a PLC Controller and Display Units,. The MODBUS protocol enables the sensors to be used directly by most SCADA applications software.
Multiparameter Housing
The ARGES Nitrate Sensor by Keynes Controls can be used as a stand-alone device or as a part of a multi-parameter solution. Keynes Controls currently manufacture 7 port and 3 port sensor housings. An optional brush unit can be installed to clean the fluorometer optics.
Only a single network connection fitted to the base of the housing is required to communicate with all the internal sensors. The internal sensors will automatically detect the network traffic and start operations.
The ARGES Nitrate sensor is integrated into the Keynes Controls Q-LOG 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.
