PocketferryBox- Instrument for mobile Applications
Objectives and Realisation
The setup of 'Standard FerryBoxes' on a ship costs time and money. The operation of the existing systems on small boats during single field campaigns in an estuary, river or a lake is not feasible.
In order to overcome these restrictions a ‘pocketFerryBox’ has been developed with the aim to have a portable, energy-independent system for fast field measurements. Despite these restrictions important oceanographic, chemical and biological should be recorded and stored.
With the new instrument accompanying measurements during sampling in the field shall enable the chemist or biologist to take samples ‘more intelligently’ according to the environmental situation. In addition, a survey of important water quality parameters should be possible, covering a large area in a short time interval.
For the development of the ‘pocketFerryBox’ the following problems had to be solved:
- Reduction of size by optimising the flow-through unit,
- Choosing small, but reliable sensors for the chemical/biological parameters,
- Encasing the system in a robust, water-resistant housing and
- Implementing a software which can be operated easily under severe conditions, e.g., on an open boat even with rainy weather.
Foto of the pocketFerryBox
All systems (except the car battery) are installed in a housing (“Zarges ®”-box) protected against rain and water spray. For transport the box can be fitted with wheels. The system is suitable for air transport; it weighs about 25 kg.
The power supply enables to operate the unit from a car battery over a period of at least 6-8 hours.
The system containes sensors for
- salinity (7-conductor cell from Sea&Sun, Germany),
- oxygen (optode from Aanderra, Norway) and
- chlorophyll-fluorescence (Cyclops, Turner)
- coloured dissolved organic matter (CDOM, Cyclops, Turner) ,
- phycocyanin (Cyclops, Turner) and
- phycoerythrin (Cyclops, Turner).
All data are recorded with a water-proof tablet PC under Windows XT. The program has been written in LabView (National Instruments). All actual data are given in alphanumerical form on the screen. In addition 6 selected parameters can be presented in graphical form as time series.
All systems (except the car battery) are installed in a housing (“Zarges ®”-box) protected against rain and water spray. For transport the box can be fitted with wheels. The system is suitable for air transport; it weighs about 25 k
Design of the pocketFerryBox
Scheme of the pocketFerryBox
Water enters the flow-through unit, equipped with sensors by means of a 12 V impeller pump with a flow rate of 3-4 l/min. The flow-through unit are identical; up to 6 units can be assembled together. In order to reduce the effective dead volume the water enters the units at the top and leaves at the bottom. Depending on the application different sensors can be selected.
Since one of the aims is to have fast surveys a versatile inlet system is under development which will enable high speed boat velocities (>10 knots). Besides its function as water supply the inlet also will contain a temperature sensor and an altimeter (echosounder) that gives information of the water depth with a moderate accuracy of ±10 cm (in tidal waters this has to be corrected). The position is recorded by a GPS receiver which can be clamped somewhere on the boat.
