DT-6234B Portable Tachometer

Display: 5 digits, 31mm blue backing LCD display
Test Range: 2.5 to 99, 999 RPM (r/min)
Total Test Range: 1 to 99, 999
Resolution: 0.1 RPM (2.5 to 999.9 RPM)
1 RPM (over 1, 000 RPM)
Accuracy: ±(0.05%+1digit)
Sampling Time: 0.8 sec. (over 60 RPM)
Test Range Select: Automatic
Detecting Distance: 50 to 500 mm / 2 to 20 inch (Laser Photo)
Sampling Time: 0.8 sec. (over 60 RPM)
Memory: Max. Value, Min. Value, Last Value. 
Battery: 4×1.5V UM-3 battery or to connect the DC 6V Regulated power supply
Power Consumption: Approx. 50mA
Operation Temp.: 0 to 50 C(32 to 122 F)
Size: 160×76×40mm