Sondes stability boost

AquaTROLL500

Water monitoring specialist In-Situ is offering a new line of fluorometers compatible with its Aqua Troll 500 and Aqua Troll 600 multiparameter Sondes (pictured). This includes sensors to measure rhodamine WT, chlorophyll a, phycocyanin (BGA-PC), and phycoerythrin (BGA-PE), all of which are relevant to applications like lake, river and coastal monitoring.

The firm says the devices represent a significant technological advance, and are the only fluorometers are the only sensors in the multiparameter water quality market that feature integrated optical compensation. Central to the measurement mechanism is a patented technology employing a second detector to compensate for LED drift over temperature and time, providing more accurate and stable measurements, according to In-Situ.

The fluorometers can also work with isolated optical frequencies, avoiding the sensor interference that normally occurs when using two sensors simultaneously. The use of separate frequencies provides a unique digital signature for each light source, minimising interference.  The parts also offer ambient light rejection, blocking the external light that can introduce bias to data.  And the approach also sidesteps problems associated with combined chlorophyll/BGA sensors that measure wide ranges of the visible spectrum at once.

The new sensors work from a narrower band of the light spectrum, and so improves measurement accuracy.