The WindObserver 65 2-Axis Solid-State Ultrasonic Anemometer (Part Number: 1390-65-B-121), engineered and manufactured by Gill Instruments Limited (United Kingdom), is a globally recognized, high-precision industrial meteorological sensor designed for critical wind monitoring applications across heavy industry, offshore marine platforms, and transport safety systems.

Model Number Breakdown & Configuration:
- 1390: Gill Instruments WindObserver Precision Ultrasonic Series.
- 65: Extended wind speed measurement envelope up to 65 m/s (145 mph / 234 km/h).
- B: Digital output communication architecture (RS422 / RS485).
- 1 (Position 1): Unheated configuration, delivering ultra-low electrical power consumption.
- 2 (Position 2): Integrated cable gland with 2-meter flying lead connection cable.
- 1 (Position 3): No base mount configuration, designed for custom or direct mounting on existing masts and flanges.

Key Engineering Features & Operational Advantages:
- Solid-State 2-Axis Ultrasonic Measurement Principle: Operates on ultrasonic time-of-flight acoustic transit technology across four paired piezoelectric ceramic transducers. Devoid of any moving mechanical parts such as rotating cups or wind vanes, it completely eliminates bearing wear, mechanical seizure from sand or airborne grime, and inertial lag. The sensor maintains lifetime calibration integrity without routine field recalibration, drastically reducing ongoing operational maintenance costs.
- Ultra-Low Starting Threshold & Broad Operating Span (0 to 65 m/s): Detects subtle air currents starting at an ultra-low threshold of 0.01 m/s and accurately tracks gale-force storm gusts up to 65 m/s with an accuracy of ±2% @ 12 m/s.
- 360° Continuous Wind Direction Tracking (No Dead Band): Provides uninterrupted directional wind measurement across 0 - 359° with 1° resolution and ±2° @ 12 m/s accuracy. Features user-selectable vector rolling averaging (1, 2, and 10 minutes) and 3-second gust tracking conforming to World Meteorological Organization (WMO) guidelines.
- Marine-Grade 316 Stainless Steel Construction: Enclosed in a heavy-duty, corrosion-resistant 316 stainless steel housing sealed to IP66 (NEMA 4X) ingress protection standards. The instrument is engineered to withstand long-term exposure to aggressive salt spray, continuous marine moisture, UV degradation, and chemical factory fumes.
- Flexible Digital Industrial Communication: Offers multi-drop RS422 and RS485 serial communication (Full and Half Duplex) supporting standardized marine NMEA 0183 protocols, Polar coordinates, Cartesian UV vectors, and ASCII formats. The user-configurable data output rate (1 Hz to 10 Hz) enables straightforward integration with industrial PLCs, SCADA architectures, automated dataloggers, and shipboard bridge displays.

Typical Industrial Applications:
- Marine vessel Dynamic Positioning (DP) systems, offshore oil & gas production rigs, FPSO units, and commercial harbor vessel traffic services (VTS).
- Aviation weather monitoring, airport runway wind shear alerting, and offshore helideck monitoring systems conforming to CAP 437 standards.
- Commercial container ports and gantry crane wind speed safety interlocks (STS, RTG, and harbor tower cranes).
- Structural health and aerodynamic safety monitoring on long-span suspension bridges, high-rise architectural towers, and road/rail tunnels.
- Utility-scale onshore and offshore wind turbine control systems (nacelle yaw alignment and pitch optimization).

• Manufacturer: Gill Instruments Limited
• Country of Origin: 100% United Kingdom (Made in UK)
• Product Line: WindObserver 65 Series 2-Axis Ultrasonic Anemometers
• Model Designation / Part Number: 1390-65-B-121
• Measurement Technology: 2-Axis Solid-State Ultrasonic Time-of-Flight
• Wind Speed Specifications:
  - Range: 0 to 65 m/s (0 to 145 mph / 0 to 234 km/h)
  - Starting Threshold: 0.01 m/s
  - Accuracy: ±2% @ 12 m/s
  - Resolution: 0.01 m/s
  - Offset: ±0.01 m/s
• Wind Direction Specifications:
  - Range: 0 to 359° (Continuous rotation, no dead band)
  - Accuracy: ±2° @ 12 m/s
  - Resolution: 1°
• Ultrasonic Data Output Rate: Selectable 1 Hz, 2 Hz, 4 Hz, 5 Hz, 8 Hz, or 10 Hz
• Output Parameters: Polar (Speed & Direction), Cartesian Vectors (U & V), NMEA format, Tunnel format
• Averaging Calculations: Rolling average (1, 2, 10 min), Gust (3 seconds) compliant with WMO No. 8 guidelines, Block average (0 - 3600 seconds)
• Digital Communication Output: RS422 / RS485 full duplex or half duplex
• Supported Baud Rates: 1200, 2400, 4800, 9600, 19200, 38400 baud
• Data Format: 8-bit data; odd, even, or no parity
• System Diagnostic Status: Built-in sensor health reporting encoded in standard data string
• Heating Configuration: Unheated version (Position 1: "1")
• Cable Connection: Cable gland with 2-meter flying lead connection cable (Position 2: "2")
• Mounting Option: No base mount included (Position 3: "1")
• Power Requirements: 9 VDC to 30 VDC (Low power draw: ~30 mA @ 12 VDC)
• Housing Metallurgy: Marine-grade 316 Stainless Steel construction
• Ingress Protection Rating: IP66 / NEMA 4X (sealed against heavy seas and high-pressure hose-directed water)
• Operating Ambient Temperature Range: -55°C to +70°C (-67°F to +158°F)
• Operating Humidity Range: 0% to 100% RH
• Precipitation Resistance: Withstands rainfall up to 300 mm/hour
• Electromagnetic Compatibility (EMC): Complies with EN 61000-6-2: 2001 and EN 61000-6-3: 2001
• Physical Dimensions: Height approx. 381 mm, body diameter 56.8 mm, head width 213 mm
• Instrument Net Weight: Approximately 1.4 kg (3.1 lbs).