Many instruments available for measuring dissolved oxygen are old-fashioned, complex to use, expensive, and require a high degree of proficiency to operate. These instruments may also require expensive additional housings and accessories before they can be deployed for any monitoring task. End users who are looking for a simple to use instrument to make dissolved oxygen measurements need look no further than that of The ARGES Dissolved Oxygen by Keynes Controls.
The ARGES Dissolved Oxygen Sensor by Keynes Controls is a single-channel instrument that can detect and report dissolved oxygen levels in the range of 0 - 100 %. The sensor has been designed to be used as a stand-alone laboratory instrument, or as part of a multi-parameter system. The instrument and can be connected directly into a plant-wide SCADA system using the in-built MODBUS and RS485 protocols. The RS485 network enables the sensors to be put onto local area and Wi-Fi networks. The SDI12 digital network connection is ideal for low power remote solutions.
In-situ measurement, no sampling, no reagents
• Direct SI Unit output of parameters
• Optical window with coating to minimise clogging
• Real time measurement
• Automatic compensation for temperature effects
When measuring concentrations of metals and minerals in water:
1 milligram per liter
(mg/L) = 1 part per million (ppm)
1 microgram per liter
(ug/L) = 1 part per billion (ppb) and 1 ppm = 1,000 ppb
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.
Q-LOG Product Application Software
The ARGES Dissolved Oxygen Sensor by Keynes Controls is supplied with a free copy of the Keynes Controls Q-LOG Applications software that can be used to calibrate, make configuration changes, test measurements, display real-time results and store measurements into a CSV text file for simple analysis in a spreadsheet. The measurements can be be shown in panel meters and charts.
Each of the ARGES sensor range is uniquely identified on a network so there is no chance of misidentification of results.
Multiparameter Housing
The ARGES Dissolved Oxygen 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 submersible brush unit is available for cleaning the fluorometer optics and this can be fitted into any port within the housings.
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. All of the sensors support SDI12, RS485 and MODBUS communications.
Multiparameter Measurements
The ARGES Dissolved Oxygen Sensor by Keynes Controls can be fitted into any of the Keynes Controls ARGEs multiparameter housings. The optional USB-SDI12-AG1 media converter shown below can be used to connect a multiparameter system, or single sensor directly to a Windows PC USB Port. The media converter powers the sensor directly and no external power supply is required.
Calibration Period and Range
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.
The ARGES Dissolved Oxygen sensor is a very sensitive device. The normal factory calibration settings are suitable for general operations. The calibration range can be user adjusted to suit the measurement application, for example 0 - 50 % DO for low concentration applications. The simplified calibration commands make this operation simple to carry out.
Product Features
| TYPE | RANGE (Typical levels) |
| Solid state Fluorometer | Optical Fluoresecent |
| Concentration range: | 0. to 10 mg/L 0-100% |
| Resolution: | 0.001 mg/L |
| Accuracy: | +/- 5 % of reading - Typical |
| Multi-parameter Housings |
7 / 3 Port Options |
| Calibration Period: | Approximately 2 year between Calibration - |
| Sensor Material | Stainless-steel body - Gold plated Connector pins |
| pH Range | 0 - 14 |
| Digital Communications | SDI12 / RS485 / MODBUS Digital Communications - 0-2 V DC Optional |
| Temperature Sensor | NTC 0 - 50 Deg C / 0.2 % accuracy |
| Simple Calibration | Two points - Multipoint Calibration Point Option |
| SI Units |
mg/L / % Dissolved H20 - Degrees Celsius |
| Analogue Output |
0-2 V DC - proportional to concentration |
Optional USB Interface
Keynes Controls manufactures a range of accessories that can be used to connect the ARGES range of sensors to a Windows computer system and enable the sensors to be used in laboratory applications, multi-parameter instruments and calibration operations.
The optional USB media converters can be used to connect a multi-parameter instrument to a PC.
Sensor Connections
The ARGES sensors are very easy to use. Simply connect the sensor to the network type of choice. The sensor will detect the network traffic and automatically start communications. It is now possible to make configuration changes and measurements.
All of the ARGES sensors have the same Pin-out as shown in the image opposite. Any ARGES sensor can be used in any port in the multi-parameter housing. The sensor interface cable connects to the top of the sensor to a PC or suitable digital network.
1 = +RS485 2 = -RS485 3 = SDI12 4 = Gnd 5 = 12V DC
Sensor Pin-out
Specifications
| ENVIRONMENTAL CHARACTERISTICS | ||||
| DO | MDL 0 % | Range 0 - 100 % | Non freeze | |
| Other ranges on request | Ambient Range: 0 - 50 Degree Celsius | |||
| Water Temperature: -2 to 50 Degree Celsius | ||||
| Accuracy | +/- 5 % of Reading | |||
| PHYSICAL DIMENSIONS | ||||
| Resolution | 0.01 % | |||
| Length x Diameter: 22 x 205 mm | ||||
| Sample Period |
|
Weight: 108 g | ||
| Wiper Trigger | SDI12 Command | aM! | Maximum Depth : 50 m - 500 m optional | |
| Excitation | UV | Built-in Network Types: | ||
| Housing | 316 Stainless Steel | MODBUS / SDI12 / RS485 / Analogue Output | ||
| Focal Point | In-front of sensor faceplate | |||
| Data Output | SI Units - %DO / Degrees C | Supply Voltage: 10 - 18 V DC Standby Current 0.3 mA 30 mA Active measurement |
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+Tryptophan-ppb+Temp (Degree Celsius) |
| Read Serial Number | aXSN! | Instrument Response a+Serial-number |
| Calibration Date | aXCDT! | Instrument Response a+date |
Built-in Communication Options
The ARGES Dissolved Oxygen 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.
Additional Information: