20-990 rpm Anemometer Drive, 115V / 60Hz

20-990 rpm Anemometer Drive, 115V / 60HzModel 18811 Anemometer Drive is identical to Model 18802 except the drive motor incorporates a gear reducer for operation in the range of 20 to 990 RPM in 10 RPM increments. The lower range is recommended for cup anemometer calibration.The Young Selectable Speed Anemometer Drive provides a convenient and accurate way to rotate an anemometer shaft at a known rate. The device consists of a control/display unit and a variable speed motor with integral high-resolution optical encoder. Model 18811 has a lower RPM range for use with cup type anemometers. High and low speed motors are available separately, permitting operation in both speed ranges with a single display unit.The control unit automatically senses motor assembly type (high or low speed) and adjusts display and controlling circuits automatically. Operating parameters for each motor type include MAX & MIN RPM, STEP SIZE, and 9 PRESET speeds. Settings for these parameters are saved when power is off. A front panel CW-CCW switch selects rotation direction (as seen facing anemometer). Motor speed is selected using the UP-DOWN keys. The display shows the target and actual RPM. Motor rotation and measurement are referenced to a crystal oscillator for stability and accuracy. Current limiting circuits protect the motor from damage due to overload or stalling. For completely portable operation, two internal 9-V batteries power the unit. Use lithium type for longest life. When batteries are low, the controller stops the motor and alerts the user on the display.