The new Rugged Dissolved Oxygen Sensor (RDO) works in conjunction with the Troll 9000 family and uses optical fluorescence sensor technology to provide stable and precise measurements. Unlike other dissolved oxygen sensors, the RDO is very low maintenance, requiring no membranes, no stirring and no cleaning. This allows the user to deploy the instrument for months without having to re-calibrate.
The RDO measurements are based upon certain substances that can act as dynamic fluorescence quenchers. This is illustrated in the diagram shown.
| Item |
Specification |
| Accuracy and precision |
+/- 0.1 mg/L or +/- 1% of reading (whichever is greater) |
| Operating Range |
0-20 mg/L or 0-450% |
| Temperature Range (operating / storage) |
0-40 deg C / -40 to 80 deg C |
| Salinity Range |
Up tp 40 ppt |
| pH range |
0-12 pH |
| Typical response limit |
>25 mg/L |
| Response Time |
T90 = 16 seconds, oxygen increasing |
| Technology |
Fluorophor impregnated membrane optical sensor, dynamic luminescence quenching technique |
| Calibration |
1 point or 2 point |
| Typical calibration duration |
12 months (clean water) |
| Known interfaces |
SO2, Cl2, biofouling from organisms that produce or consume oxygen. No interface from@ CO2, H2S, pH, any ionic species |
| Chemical exposure |
Safe with methanol and ethanol. Avoid organic solvents |
| Materials |
Titanium or 316L Stainless steel / Delrin |
| Sensor foil technology |
Platinum porphyrine lumniphore embedded in polyester |
| Sensor foil coating |
Teflon |
| Sensor foil life / RDO warranty |
5 years and 10-second interval / one year |
| Typical foil service life |
13 million measurements (e.g 5 years at 10 second interval) |
| Power requirements |
1 long-life lithium, 4 alkaline D-cell batteries, or external power |
| Dimensions, RDO sensor |
36mm (1.4in) OD. 89mm (3.5in) length. |
| RDO Sensor adaptor assembly |
88.4mm (3.5in) OD. 20.3cm (8in) length. |
