This is normal. It seems to work, but not fast, and I daresay this is accurate enough for those assembling a sports engine. enough for a regular lawnmower. My freaky, I have to remove the batteries to turn it off. And it's a guessing game as to whether it works the way it's supposed to. But when it happens, it happens.
FITNATE Tachometer Batteries Reflective Instruction
3 Review
π Highly Efficient REED Instruments R7050 Compact Tachometer: Boost Performance with Precision Monitoring
3 Review
π Enhanced Precision and Functionality: Protmex Reflective Tachometer
3 Review
Handheld Digital Laser Tachometer Non-Contact RPM Meter Motor Speed Gauge Gun Measuring Range: 2
3 Review
Digital multimeter RGK DM-12
6 Review
π¬οΈ Advanced 3-in-1 Indoor Air Quality Monitor with CO2/RH/Temp Data Logging and Audible Alarm - NDIR Sensor Technology
8 Review
π Enhanced Precision with Backlit Professional Manometer for Differential Ventilation
6 Review
Portable Handheld Manometer π for Accurate Pressure Differential Measurement
5 Review