mulfunctional tachometer dt6236b

photo／contact tachometer
surface speed meter
dt6236b
5 digits 18mm (0.6″) white backlight lcd
accuracy: ±(0.05%+1 digit)
sampling time: 0.5 sec(over 120rpm)
range select: auto-ranging
memory: max. value, min. value,
　　　　 last value. can store 96s data.
time base: 6mhz quartz crystal
detecting distance: 50~500mm
measuring range:
photo tach: 2.5~99,999rpm
contact tach: 0.5~19,999rpm
surface speed: 0.05~1,999.9m/min
resolution:
photo tach: 0.1rpm(2.5~999.9rpm)
　　　　　　1rpm(over 1,000rpm)
contact tach: 0.1rpm(0.5~999.9rpm)
　　　　　 　 1rpm(over 1,000rpm)
surface speed: 0.01m/min(0.05~99.99m/min)
　　　　　　　 0.1m/min(over 100m/min)
battery: 4×1.5v aa size battery or to external
　　　　dc 6v regulated power supply