Series-Mark-II-WSI

Supported Applications

The Dwyer Series Mark II Wind Speed Indicator is a pneumatic fluid-column instrument designed for weather monitoring stations. Operating on the principle of aircraft speed indicators, the system measures wind speed and direction using an outdoor pick-up vane connected to an indoor or outdoor indicator via flexible tubing.

Operating Conditions & Performance

The series provides direct wind speed indication through a liquid-filled scale calibrated in miles per hour (0-80 mph) or kilometers per hour (0-130 kph), alongside the Beaufort Scale of Wind Force ranging from 1 to 12. The indicator responds to changing wind speeds as fluid levels rise and fall within the column.

Performance notes include:

• A gust overrange condition is indicated if gage fluid appears in the tubing, which may occur with winds exceeding 90 MPH (145 KPH).
• Heavy wind-driven snow can temporarily affect readings until it thaws or evaporates.
• The instrument requires free passage of air through both tubes; kinks or flattening will impact accuracy.

Configuration Options

The complete kit includes an ABS plastic weather vane, 50 feet of flexible double-column tubing (red striped and plain), mounting hardware, gage fluid, and instructions. The system is configurable for different scale preferences:

• Mark II WSI: Scale in miles per hour.
• Mark II WSI Metric: Scale in kilometers per hour (0-130 kph).

The indicator body is constructed of ABS plastic. Mounting options include a Roof Top Mounting Kit, Part No. 020, and Tube Clamps, Part No. 285.

Key Product Differences

Variants within the series differ primarily by scale units:

• Miles per Hour (mph): Models such as MARK II WSI and MARK II WSI-NIST display wind speed in mph.
• Kilometers per hour (kph): Metric models, including MARK II WSI METRIC and MARK II WSI MET-NIST, provide readings up to 130 kph while maintaining the same Beaufort scale reference.