This is the Transmit Unit that affixes above the water/river and gathers the height information and transmits it to the Receive Unit.

The unit utilises an ultrasonic technique to measure the height or distance of a water surface from it - between approximately 0.5 to 10 metres. The unit gathers the height data and broadcasts it to a remote receive unit that analyses and displays the information received.

The system was originally designed to measure the change in river height to assist the fishing fraternity interested in monitoring the changes of river height in Scotland (UK), and its influence on migratory salmonids.

It was subsequently realised that this system could be adapted to inform river authorities or other individuals interested in monitoring river height, of (potential) flood situations.

The DTi assisted financially in this adaptation and herein is described the current system.

The system allows a non-invasive measurement to be made without a direct physical connection between the unit and the water. The system has a wireless link to the receiver, thereby allowing it to be used in unusual environments, typical of those encountered on a riverbank.

The transmit unit in its simplest form is housed on anything that would support and suspend it over the water height to be measured. Examples of this would be bridges, piers, footbridges solid branches of trees or even a tripod in the river!

The transmitter takes a number of measurements every 2 minutes (approximately) and transmits the data to the receive unit where it is analysed. The data consists of a height component, the air temperature (and/or any other weather parameter) and a battery state indication. Between these measurements the unit ‘sleeps’ to conserve power. The unit may be powered from the mains, battery packs of various sizes, or a maintenance free solar unit.

If the transmitter is in a remote area where RF transmissions are hampered, a combination of transmitter and receivers (or repeaters) are available to suit most locations and the basic unit has a range of 75metres (250m line-of-sight) but extended ranges are available.

Power Requirement: The transmit units operate off an external 9-38v DC supply and consumes < 3mA quiescent & 14mA for 1.5s during transmission.

A 3m power lead is provided and the user defines where the battery is positioned as it may need to be hidden in areas were it may be seen and accessed by walkers, fishermen, canoeists or vandals.

A solar powered version is available with a clear plastic lid with the solar cell behind.

NB// The technology used requires that the transmitter unit has a clear unobstructed ‘view’ of the water surface within a radius of approximately 1metre. The unit can be angled up or down to help in positioning and has a clamp lock support bracket supplied.

 

Applications: River Height Analysis for Flood/fishing/or any water height data evaluation. Tidal Monitoring, Sea Height Logging. Liquid tank monitor depth/height gauge.

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