Tide gauges

Picture of Munro float gauge

Munro float gauge
The Munro gauge measures sea level by means of a float in a stilling well.

The float is about 45cm diameter - the large diameter reduces inevitable errors in buoyancy due to friction of the gearing and small changes in the length of float wire.

This wire is coiled round a drum on the end of the gauge and another drum contains the counter balance wire.

The drum is geared to a slotted tape attached to a pen carriage which travels the chart during the rise and fall of the tide.