Digital Hour Meter, 4-Digit Tachometer, Motion, Speed ​​and Force Tachometer NPN Hall Switch Sensor (Red)(Blue)

The LED digital tachometer uses the latest A/D conversion chip and a high-stability reference integrated circuit, employing electronic chip components and a well-designed circuit layout. It can be used to measure voltage, current, and external sensors to measure temperature, pressure, displacement, and other physical quantities. It is suitable for all types of digital instrument displays. Specifications: Measurement accuracy: ±0.1% Display mode: 0.56" LED Display refresh rate: > 3 times/sec Working power supply: DC8-24V, 30mA, Measurement range: 10-9999RPM Hall proximity sensor: magnetic Appearance size: 80 x 42 x 25 mm / 3.14 x 1.65 x 0.98 inches LED display (optional): red, blue Weight: 80 g (red), 105 g (blue) Over-count display: the first digit displays "1" or "-1", and the last three digits do not display. Precautions: 1. Connect the plug correctly according to the wiring diagram. 2. Avoid strong electromagnetic interference; it is best to use shielded or double-stranded wire when measuring conductors. 3. The meter's counting signal and the zero-compensation signal input switch or circuit should be as close as possible. 4. Avoid running the signal line from the meter terminal to the same conduit or twisted trace line as possible. 5. Avoid running the same conduit or twisted trace line alongside other wires such as high-voltage wires or power supply wires to prevent unnecessary interference. If necessary, use shielded wire; the shielding layer connects the negative terminal of the meter to the negative terminal. 6. Mechanical switches or microswitches are not recommended as they have a relatively short lifespan and may malfunction after prolonged use. If you must use them, try higher-quality models.