Many instruments available for measuring fluorescence of Chlorophyll 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 fluorescence measurements of Chlorophyll need look no further than The ARGES Chlorophyll Sensor by Keynes Controls.
The ARGES Chlorophyll Sensor by Keynes Controls is a single-channel instrument that can detect and report Chlorophyll levels in the range of 0.5 - 1000 ppb.
Operations
The ARGES Chlorophyll Sensor by Keynes Controls 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 in-built MODBUS protocol. The SDI12 and RS485 digital networks enable the sensors to be directly connected to Web based Data Loggers, Wi-Fi and Local Area Networks.


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
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.
Why Measure Chlorophyll Concentration?
Chlorophyll is the green pigment found in plants, and it plays a vital role in photosynthesis. During photosynthesis, the Chlorophyll the energy of the sun and converts into chemical energy. Photosynthesis uses this chemical energy to produce glucose from carbon dioxide and water.
Some types of organic matter fluoresce at the same wavelengths as tryptophan. ‘Tryptophan-like’ fluorescence in river water is associated with the presence of organic matter that can be easily degraded by microbes. This type of organic matter can arise in rivers from sewage inputs, from farm wastes such as cattle and pig slurry and silage. So the measurements from the ARGES-Tryptophan sensor can be used to identify the presence of these organic wastes in a river.
Measuring the chlorophyll concentration in water is essential for estimating the abundance of phytoplankton.

Q-LOG Product Application Software
The ARGES Chlorophyll Sensor by Keynes Controls is supplied with a free copy of the Keynes 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 Q-LOG Software can display single and multiple sensors across a network. This can be individual instruments or multiple SONDES. The results can be shown on a panel meter, charts or into a spreadsheet.
The image opposite shows a single sensor in test calibration solution.
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.
Keynes Controls offer calibration solutions for The ARGES Chlorophyll Sensor by Keynes Controls which are available from the online shop.
Optional Accessories
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 converter can be used to connect The ARGES Chlorophyll Sensor by Keynes Controls, or a multi-parameter instrument containing the Tryptophan Sensor to a Windows PC. Free applications software enables measurements to made and results displayed. The QLOG software can be used to adjust the instrument configuration.
Product Features
TYPE | RANGE (Typical levels) |
Solid state ISE sensor. | |
Concentration range: | 0.5 to 1000 µg/L |
Resolution: | Five auto range scales: 0.00 - 999.9mg/l. |
Accuracy: | +/- 3% of reading. |
Stand-alone and SONDE Multi-parameter operations |
|
Sensor life: | Approximately 1 year, depending on usage. |
Interference IONS | Mercury, Silver, Cupric |
pH Range | 3 - 7 |
Sensor Element | Isolated between measurements |
Digital Communications | SDI12 / RS485 / MODBUS Digital Communications |
Full Digital Operation | |
Simple Calibration | Multi point Calibration Point Option |
SI Units |
µg/L | Analogue Output |
Multiparameter SONDE Housing
The ARGES Chlorophyll 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 Fluorometer sensors by default take measurements sequentially and as such there will be no light pollution between sensors that can affect the results of adjacent fluorometers. Some of the filters for the different model sensors can operate at similar wavelengths and as such, a sensor monitoring for a specific chemical could effect the levels measured on a similar device.
Shade Cap
A shade cap shown below, containing a baffle is screwed onto the end of the housing. The shade cap prevents damage to the sensor optics and also prevents background illumination for the fluorometers that can affect results. A baffle is used to ensure that the water flow is restricted to ensure accurate measurements can be made.
The shade cap is only required when deploying the sensor without a SONDE multi-parameter housing, or for sensor operations in the lab. Replacement caps can be ordered from the on-line shop.
Specifications
ENVIRONMENTAL CHARACTERISTICS | ||||
Tryptophan | MDL 0.05 ppb | Range 0 - 1000 ppb | ||
1 ppb | 0 - 5000 ppb | Ambient Range: 0 - 50 Degree Celsius | ||
Water Temperature: -2 to 60 Degree Celsius | ||||
Precision | 0-100 NTU | |||
PHYSICAL DIMENSIONS | ||||
Length x Diameter: 22 x 220 mm | ||||
Pulse Width |
|
Weight: 97 g | ||
Wiper Trigger | SDI12 Command | aM! | Maximum Depth : 600 m | |
Excitation | Infra-red | Built-in Network Types: | ||
Housing | 316 Stainless Steel | MODBUS / SDI12 / RS485 | ||
Focal Point | In-front of sensor faceplate | |||
Data Output | SI Units - ppb / Degrees C | Supply Voltage: 10 - 15 V DC Standby Current 8 mA / 80 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+Lead-µg/L+Temp (Degree Celsius) |
Built-in Communication Options
The ARGES Tryptophan Sensor by Keynes Control 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.

Q - Log Software
The ARGES Chloride 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.
Our highly chemical sensors provide chemical concentration and local temperature readings in SI units (Engineering units). Customize the SI units based on your instrument's capabilities, including support for multiple units like turbidity sensors, all easily managed through the device setup.
Experience the convenience of Q-LOG, enabling you to effortlessly make and install calibration values into your instrument.
Connect our Fluorometers directly to SDI12, RS485, and MODBUS networks, leveraging the versatility of Q-LOG to acquire measurements on SDI12 and RS485 networks. SDI12 communications are perfectly suited for seamless integration with data loggers, while RS485 is ideal for larger-scale network applications. Maximize efficiency by simultaneously testing all sensors of a multi-parameter instrument prior to deployment.
For added convenience, the optional USB interface allows you to comprehensively test and validate the sensors' operations, ensuring seamless integration into your own application and trust in the performance and accuracy of our multi-parameter systems!


MODBUS Operations
ALL of the ARGES range of chemical sensors support MODBUS network operations The sensors act as a slave unit only and can communicate to suitable controllers and SCADA systems that support the MODBUS Protocol. The sensors support 16 and 32 bit registers. .
The ARGES sensors can be connected to a PC based system using the optional USB-485-Pro media converter. This device can power the chemical sensor and supports the correct timing protocols for data transmission for MODBUS and standard RS485 network communications