DT2234A+ photoelectric tachometer LEDDetailed product description：

Technical Specifications:

Specification: 5-digit large screen LCD display with a font height of 18mm
Test range: 2.5-99999 revolutions per minute (RPM)
Resolution: 0.1RPM (2.5-999.9RPM)
1RPM (above 1000RPM)
Accuracy: ± (0.05%+1 word)
Sampling time: 0.5 seconds (above 120RPM)
Range selection: automatic switching
Effective distance: 50mm -250mm
Working current: maximum 40mA
Memory: Automatically remembers the maximum value, minimum value, and last measured value
Time base: 6MHz quartz crystal
Time reference accuracy: 10 × 10-6 (0 ℃~50 ℃)
Power supply: 3 × 1.5V No.7 battery
Size: 184 × 76 × 30mm