Psychro-Dyne Portable Battery-Operated Psychrometer

Manufactured to rigid U.S. Weather Bureau and Navy specifications for indicating wet and dry bulb temperatures for relative humidity and dew point determinations. Reads from 10°F to 120°F in 1° graduations. The Organic thermometer eliminates the danger that broken mercury thermometers pose around electrical or electronic equipment. Features a miniature fan which provides constant air motion over the 8-7/8” thermometers - no whirling is required. Humidity is determined from included psychrometric tables. Each lightweight unit includes a high-impact case, pair of matched thermometers, magnetic fan motor, 2 oz. plastic water bottle, illuminating lamp, psychrometric slide rule, spare parts kit including wick and lamp, and manual. Three D-cell batteries (sold separately) last about 1,000 operations. Meets federal spec. GG-P-725B.