MD69AZI THOMSON PATT AZIMUTH SIGHT

Description A precision Azimuth reading instrument for taking accurate bearings. Based upon the William Thomson (Lord Kelvin) pattern. For use with the MARINE DATA MD69 Series of Bearing Compass Repeater. • Maximum Altitude: 60° above the Horizon. • Minimum Altitude: 10° below the Horizon. • Equipped with a UV Sun filter and a neutral density filter. • Milled prism adjustment thumbwheels. • Non-magnetic Naval Brass construction. Specifications Physical: • Type: Thomson pattern Azimuth reading device, Group II. • Weight: 1.93kg. • Dimensions: 257mm OD; 246.3mm ID; 110mm overall height. • Mounting: Fits the MD69 Series of Bearing Compass Repeater. • Reflector: Rotating 60° triangular prism, 30mm length. • Sun Filters: UV filter (Schott RG780, 0.8mm); Neutral Density filter (Schott NG1, 1.0mm). • Collimating Lens: Diameter = 33mm; Focal length approx. 100mm. • Spirit Level: Sensitive to tilt of <1°. • Shadow Pin: Not required. • Construction: Naval Brass. • Finish: RAL9005 satin black paint. Operational: Maximum and Minimum Altitudes: Method I: For taking bearings of landmarks or objects with low luminosity (the arrow on prism adjustment thumbwheels = DOWN). A distant object is sighted directly by the eye with the compass card being simultaneously viewed indirectly through the prism. Maximum altitude 34° above the horizon; minimum altitude 10° below the horizon. Method II: For taking bearings of the sun or other celestial objects (the arrow on prism adjustment thumbwheels = UP). The compass card is viewed directly through the collimating lens with a distant object being simultaneously viewed indirectly through the reflecting prism. Maximum altitude 60° above the horizon; minimum altitude 1.5° below the horizon. Environmental Operating Temperate: -10°C to +70°C.