Types of Anemometers20-28. The DIC-3 anemometer (NSN 6660-00-X03-9572) is a handheld, compact, lightweight, factory- calibrated device approved for use during Airborne operations. The DIC-3 uses folding cups to catch the wind and electronically display wind speed, but not direction. During use, it is critical that the cups are fully extended to ensure an accurate reading. The device is omnidirectional and does not need to be oriented with wind direction to provide accurate readings. Post manufacture calibration methods are not available. The DIC-3 can depict wind data in knots, miles per hour, kilometers per hour, or meters per second. The additional features of the DIC-3 are the ability to display peak wind velocity over a given period, and average wind speed over two time periods. The DIC-3 utilizes a nine-volt battery.20-29. The Turbometer anemometer (NSN 1670-00-T33-9004) is a small, lightweight, electronic wind speed indicator. It can also be commercially purchased. It does not display direction, but when turned into the wind, it depicts wind data in knots, miles per hour, meters per second, and feet per second. For the most accurate results, the Turbometer must be oriented within 20 degrees of the wind direction, with the wind entering the rear of the meter. Because the Turbometer cannot be calibrated, conduct the same pre-operation and three-anemometer check as when using the DIC-3 anemometer.Note. The unidirectional anemometers must be held in the wind line with the wind entering the rear of the meter to ensure accurate readings.