hand held tachometer DT6235B optical tachometer handheld tachometer

Model : DT6235B

CONTACT   TACHOMETER
SURFACE SPEED METER
LINE LENGTH METER 
DT6235B 
Display: 5digits 18mm(0.6") Yellow green backlight LCD Accuracy: ±(0.05%+1 digit)
Sampling Time: 0.5 sec(over 120RPM)
Range Select: Auto - Ranging
Memory: Last value,Max. Value,Min.value
Can store 96s data 
Time Base: 6MHz Quartz crystal
Power Consumption: Approx 45mA
Measurement:
CONTACT TACH 0.5 to 19,999RPM
SURFACE SPEED(m/min) 0.05 to 1,999.9(m/min)
SURFACE SPEED(ft/min) 0.2 to 6,560ft/min
Resolution: 
CONTACT TACH: 0.1RPM(0.5 to 999.9RPM)
1RPM(over 1,000RPM)
Surface speed(m/min) 0.01m/min(0.05 to 99.99m/min)
  0.1m/min(over 100m/min)
Surface speed(ft/min) 0.1ft/min(0.1 to 999.9m/min)
  1ft/min(over 1,000ft/min)
Power: 4X1.5V AA Size Battery or to external DC 6V Regulated power supply