Tachometer LCD Digital Handheld Contact Non Contact 4 Test Mode High Accuracy RPM Wide Range Item Type: Tachometer Battery: 4 x 1.5V AA battery(not included) Features: Photoelectric contact tachometer or line tachometer 5 bit large screen LCD display, word height 18mm Wide measuring range and high accuracy 10 new surface speed sensors with groove type slots for easy measurement of wire, cable and rope speed and length Range Non contact speed 2.5~99999 RPM Contact speed 0.5~19999 RPM Contact line speed (metric) 0.05~1999.9 meter/min Resolution Non contact speed 0.1 RPM (2.5~999.9 RPM) 1 RPM (over 1000 RPM) Contact speed 0.1 RPM (0.5~999.9 RPM) 1 RPM (over 1000 RPM) Contact line speed (metric) 0.01 meter/min (0.05~99.99 meter/min) 0.1meter/min (more than 100meter/min) Accuracy ± (0.05%+1） Effective distance 50~500mm Memory function Maximum value, minimum value, last value (automatically store 96 groups of data) Sampling rate 0.8 seconds (above 60 RPM) Low battery indication √ Working current About 65mA Timing 6MHZ quartz crystal Timing accuracy 10x10 to the minus sixth power (0~50℃) Maximum display 99999 Operation mode Free conversion