What weather sensors are used offshore?
Offshore platforms, wind farms, vessels and buoys measure wind, temperature, humidity, pressure and rainfall. What the environment demands and what certification decides.
Offshore platforms, wind farms, vessels and ocean monitoring systems typically use sensors to measure wind speed, wind direction, temperature, humidity, atmospheric pressure and rainfall. Depending on the application, wave, sea-state and oceanographic measurements may also be included. Offshore sensors must withstand salt spray, vibration, severe weather and long deployment periods while delivering dependable environmental data with minimal maintenance.
Four offshore situations, four different answers
| Situation | What dominates the choice | Typical answer |
|---|---|---|
| Fixed platform, non-classified area | Salt, extreme wind, and the cost of getting a technician out there | WindObserver in stainless steel 316, sized with headroom above the worst-case site wind |
| Classified area on a platform, near hydrocarbons | Certification, which nothing else substitutes for | WindObserver IS with its certified interface mounted in a safe area |
| Vessel or moving platform | True wind, so heading and platform speed as well as wind | MaxiMet GMX260 or GMX560 for the 6-axis compass and IP68, or a WindObserver with vessel heading |
| Buoy or autonomous surface vessel | Size, weight, power and submersion | WindUltra, 270 g with a 1 inch pole mount, IP66, IP68 and IP69k, under 100 mW unheated |
What the sea does to instruments
- Salt. Continuous aerosol, not occasional spray. It attacks fasteners, glands and dissimilar-metal joints before it attacks the sensor body. Stainless steel 316 on the WindObserver range is the answer at sensor level, and matching the mount and fixings is the answer at installation level.
- Vibration. Machinery, helideck operations and structural response. Nothing rotating means nothing to loosen or unbalance.
- Motion. A vessel or floating structure moves in six degrees of freedom, which turns every wind measurement into an apparent wind measurement.
- Access. The reason offshore specifications run tighter than onshore ones. A sensor change may need a vessel, a crane, a permit and a weather window, and it may wait months for all four.
The certification question
On any installation where a classified area is in play, wind measurement stops being a performance question and becomes a certification one.
WindObserver IS is the only intrinsically safe Gill anemometer. It carries ATEX, IECEx and UKEX, with EN 60945:2002 for EMC. There is no intrinsically safe WindSonic, WindUltra or MaxiMet, and no amount of ingress protection changes that.
- The anemometer, Gill part 1360-PK-052, in the hazardous area
- Its certified interface in a non-hazardous area: LVPCI 1360-PK-055 for low voltage, or 1360-PK-053 for mains
- Hazardous-area wiring rules followed throughout, because the certification covers the system
Two things people get wrong on the IS. It is unheated, so it is not the answer for icing on a classified deck. And while its factory calibration is traceable to national standards, individual calibration certificates are not available, so if a quality system requires a certificate per instrument the IS has to be handled differently from the rest of the range.
Marine approvals, stated precisely
Lloyd’s Register Type Approval applies to WindObserver 65, 70, 75 and 90 and to the WindObserver II. The II additionally carries ABS Product Design Assessment. The WindObserver IS carries neither, and its current datasheet removes those logos.
That distinction is worth getting right in a tender response. Claiming Lloyd’s for the IS is a factual error that a marine classification surveyor will find.
Helidecks
Helideck monitoring is its own case, combining wind for the approach with the hazardous-area classification that comes with fuel and with the motion of a floating unit. It usually resolves to a certified wind measurement feeding a helideck monitoring system, and it is worth treating as a system specification rather than a sensor purchase.
What to take away
- Fixed platform, classified area, vessel and buoy are four different specifications.
- WindObserver IS is the only intrinsically safe Gill anemometer, and its interface goes in a safe area.
- The IS is unheated. Its factory calibration is traceable to national standards, but individual calibration certificates are not available.
- Lloyd’s applies to WindObserver 65, 70, 75, 90 and the II. Never claim it for the IS.
Questions that usually come next
What is the best wind sensor for harsh environments?
Salt, ice, vibration, dust and submersion each demand something different. How to match a wind sensor to what the site actually does to it.
Read the answerHow ultrasonic measurement worksWhat is the difference between true wind and apparent wind?
Apparent wind is what a moving platform measures. True wind is the atmospheric wind after platform motion is removed. Why the difference matters and what it needs.
Read the answerCalibration and traceabilityHow are wind sensors calibrated?
Wind sensors are calibrated against traceable reference standards in a wind tunnel. What calibration proves, what UKAS accreditation adds, and what it does not do.
Read the answerHave an application to discuss?
Speak to our team
Tell us what you need to measure, where and under what conditions. We'll help you work out the appropriate approach.