PHOTO/CONTACT TACHOMETER(Laser),LINE-SPEED METER
Model: DT2236B
Display: 5digits 18mm (0.6 in) LCD
Accuracy: (0.05%+1digit
Sampling Time: 0.5sec (over 120RPM)
Range select: Auto-Ranging
Memory: Last #118alue, Max. #118alue and Min. #118alue
Measuring Range: PHOTO TACH: 2.5 to 99,999RPM ( กรณีที่วัดโดย laser )
CONTACT TACH: 0.5 to 19,999RPM ( กรณีที่วัดโดยแตะที่เพลา)
SURPFACE SPEED (m/min): 0.05 to 1,999.9m/min
Resolution: PHOTO TACH: 0.1RPM (2.5 to 999.9RPM)
1RPM (over 1,000RPM)
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)
Battery: 4 X 1.5V AA battery 
Detecting Distance: 50mm to 500mm (Laser)
Time Base: 6MHz Quartz crystal
Power consumption: Approx. 45mA
Measuring through the two tops, more conveniently and quickly