DC 8-24V 10-9999RPM Digital LED Tachometer, RPM Speed Meter, with Hall Switch Sensor 

Features: 

With a standard size, easy to install. 

Have good stability, high measurement precision. 

Strong anti-jamming capability. 

Packing List: 1x Digital tachometer. 1x NJK-5002C ordinary hall switch. 1x Wire harness. 

Specifications: 

Item name: Digital LED Tachometer 

Type: LED Tachometer, RPM Speed Meter. 

Switch type: NJK-5002C ordinary hall switch(Note: If there is a frequency converter on the device that will interfere with the detection of ordinary Hall switches, it is recommended to use anti-interference Hall switches instead.) 

Color: Black, display color: red,green,blue. 

Working power supply: AC/DC8-24V, 40mA 

Display mode: 0.56" LED, four readings 

Measuring range: 10-9999RPM 

Measurement accuracy: ±0.1%, reading ±1 character 

Clear zero: automatic 

Display refresh rate: >3 times/second 

Over-range display: if the speed is too low, it will display "LLLL", if the speed is too high, it will display "HHHH". 

Sensor wiring: brown-Power+;blue-Power-;black-signal. 

Operating temperature: -10 to 50°C.Operating humidity: 10 to 80% (without condensation). Operating pressure: 80 to 106kPa. 

Item size: as shown 

Total weight: about 80g/2.82ouce 

Precautions for use: 

1. Connect the plug correctly according to the wiring diagram. 

2. The Hall switch is NPN normally open type, and the detection distance of the Hall switch needs to be within 10mm. The installation diameter of the Hall switch is 12mm, and the wire length is within 1 meter. 

3. Strong electromagnetic interference should be avoided. It is best to use shielded wires or twisted pairs for measuring wires. 

4. The counting signal of the counter and the switch or circuit of the reset signal input should be as close as possible to the terminal of the counter, so that the signal line is as short as possible. 

5. Avoid the same tube or twisted wiring with other such as: strong electric wires or power wires, etc., to avoid unnecessary interference. If necessary, please use shielded wires, and the shielding layer is connected to the counting terminal "+". 

6. It is not recommended to use mechanical switches or micro switches, because their lifespan is relatively short, and it is easy to miscount after a long time; if you use mechanical switches or micro switches, please try to use better quality ones to avoid miscounting. It is recommended to use a magnetic switch. 

Note: 

Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 10-30mm.