4 Digital LED Tachometer RPM Speed Meter Hall Proximity Sensor NPN(Red)

Good stability, high and strong anti-interference ability The external apprance adopts standard size and convenient to install Input pulse signal: NPN/PNP open collector ,contact , contactless , pulse Descriptions: Digital LED tachometer adopts the latest A/D conversion chip and the high stability benchmark IC, adopts electronic chip component, rsonable circuit design. It can be applied to the msurement of voltage, current and external sensor to msure temperature, pressure, displacement and other physical quantities. Suitable for all kinds of digital instrument display. Ftures: Good stability, high and strong anti-interference ability. The external apprance adopts standard size and convenient  to install. Input pulse signal: NPN/PNP open collector ,contact , contactless , pulse. Input signal voltage: low 30V -0.6 V, high : 4-30V. Msuring range: frequency: 9Hz, .9 HZ, 99.99 KHZ, automatic ing NaSelection. Specifications: Msurement accuracy: +-0.1 Display mode: 0.56"LED Display rate: 3 times/sec Working power supply: 8-24V, 30mA, msurement range: 10- 9RPM Hall proximity : magnetic Apprance size: 80 x 42 x 25mm/3.14 x 1.65 x 0.98inch LED display(Optional): red, blue Weight: 80g(red),105g(blue) Overrange display: the first one shows "1" or "-1", and the latter three do not show Precautions: 1. Connect the plug correctly according to the wiring diagram 2. Should avoid strong electromagnetic interference and it is better to use shielded wire or double stranded wire for msuring conductors 3. The counting signal of the counter and the of the clring signal input or the circuit shall be as close as possible to the terminal of the counter to make the signal line as short as possible 4. Avoid with other such as: high voltage wires or power wires and so on with same tube or twisted  trace line, in order to avoid unnecessary interference.If necessary, plse use the shielded wire, shielding layer connect the"+" of the count terminals 5. It is not recommended to use a mechanical or because they have a relatively short life span and can be counted by mistake after time. If you use a mechanical or a , plse try to use a better quality, so as not to miscount, and strongly suggest a magnetic control Package Included: 1 x Tachometer 1 x Hall NPN proximity sensor