Wind Sensors

Three ways to measure wind

Mechanical sensors — propeller-and-vane or cup — have been measuring wind for a century and still do it well. Different designs behave differently at the extremes: some start turning in almost no wind, others survive gusts that would destroy a lighter instrument. Bearings wear, so they need periodic service, and the temperature range matters in cold climates.

Ultrasonic sensors time sound pulses across a fixed path, so nothing turns and nothing wears. That makes them the sensible choice on a high mast or anywhere access is difficult and expensive, and it removes most of the calibration burden.

Wind LiDAR measures remotely, profiling speed and direction at many heights at once from a single unit on deck. Nothing is mounted at height, so there is nothing at height to damage or maintain — valuable offshore, and the usual way to characterise wind across a whole wind farm rather than at one point on it.

What matters offshore

• Hazardous area. Where the mast sits in a classified zone an intrinsically safe or ATEX-certified sensor is required. We supply intrinsically safe ultrasonic and mechanical options, and Ex packages complete with their own interface module.
• Icing. A frozen anemometer reads zero and gives no sign that it is wrong. Heated sensors keep measuring through freezing spray, and the amount of heating needed scales with how bad the icing gets.
• Location, location, location. More bad wind data comes from siting than from instruments. Turbulence off a structure, shadowing from a crane or flare, and disturbed flow around the mast itself all corrupt the reading, and none of it shows up as an obvious fault. Wind sensor location — why it matters and what to do about it covers this in the Knowledge Base, and our engineers will advise on a specific installation.
• True versus relative wind. On anything that moves, the sensor measures relative wind. True wind is computed from that, the heading and the speed over ground — so the heading and position inputs matter as much as the anemometer does.

Examples from our range

A few of the wind sensors we specify, install, integrate and maintain. We supply more types and variants than are listed here.