Digital Tachometer 5 Digit LCD Display Handheld Speed Guage Contact and Photoelectric Tachometer Item Type: Digital Tachometer Model: DT2236B Battery: 4 x 1.5V AA Battery (battery not included) Screen: 5 digit large LCD display, with a word height of 18mm Function: Wide measurement range and high accuracy. 10 new types of surface speed sensors, equipped with slots, can conveniently measure the speed and length of wires, cables, and ropes Range: Non Contact Speed: 2.5-99999rpm Contact Speed: 0.5-9999 rpm Contact Line Speed (Metric): 0.05-9999 meters per minute Resolution: Non Contact Speed: 0.1rpm (2.5-9999.9rpm); 1rpm (above 1000rpm) Contact Speed: 0.1rpm (0.5-999.9rpm); 1rpm (above 1000rpm) Contact Line Speed (Metric): 0.01 meters per minute (0.05-99.99 meters per minute); 0.1 meters per minute (over 100 meters per minute) Sampling Rate: 0.8 seconds (above 60 rpm) Low Battery Indication: Yes Working Current: 50mA Timing Accuracy: 0-50℃ Maximum Display: 99999 Operation Method: Free Conversion Accuracy: ±(0.05%+1) Effective Distance (Laser): 50-500mm Effective Distance (LED): 50-250mm Memory Function: Maximum, minimum, final value Size: Approx. 7.5 x 3.5 x 20cm / 3 x 1.4 x 7.9in