4 Digital LED Display Tachometer RPM Speed Meter Panel Inductive Hall Effect Sensor NPN Proximity Switch Red/Blue(Blue)

Digital LED tachometer adopts the latest A/D conversion chip and the high stability benchmark IC, adopts electronic chip component, reasonable circuit design. It can be applied to the measurement of voltage, current and external sensor to measure temperature, pressure, displacement and other physical quantities. Suitable for all kinds of digital instrument display.  

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 switch : magnetic
Appearance 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 measuring conductors
3. The counting signal of the counter and the switch of the zero clearing 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, please use the shielded wire, shielding layer connect the"+" of the count terminals
5. It is not recommended to use a mechanical switch or micro switch because they have a relatively short life span and can be counted by mistake after long time. If you have to, please try better quality ones, strongly suggest a magnetic control switch

Package Included:
1 x Tachometer
1 x Hall NPN proximity sensor