Model Number:Health Geargxodpg105z-01 Product Dimensions:8 x 7 x 4 cm; 80 Grams Material:PLA_(Polylactic_Acid), PE_(Polyethylene) Item Weight:80 g Specifications:Measurement accuracy:0.1%Display mode: 0.56"LEDDisplay refresh rate: >3 times/secWorking power supply: DC8-24V, 30mA, measurement range: 10-9999RPMHall proximity switch: magneticAppearance size: 80 x 42 x 25mm/3.14 x 1.65 x 0.98inchLED display(Optional): red, blueWeight: 80g(red),105g(blue)Overrange display: the first one shows "1" or "-1", and the latter three do not showPrecautions:1. Connect the plug correctly according to the wiring diagram2. Should avoid strong electromagnetic interference and it is better to use shielded wire or double stranded wire for measuring conductors3. 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 possible4. 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 terminals5. 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 use a mechanical switch or a micro switch, please try to use a better quality, so as not to miscount, and strongly suggest a magnetic control switchPackage Included:1 x Tachometer1 x Hall NPN proximity sensor About this item [Great Performance]: Tachometer RPM Speed Meter And Hall Proximity Switch Sensor feature good stability, high precision and strong anti-interference ability [Item Specifications]: Input signal voltage: low level: -30V -0.6 V, high level: 4-30V; Measuring range: frequency: 9999Hz, 999.9 HZ, 99.99 KHZ, automatic switching selection [Convenient to Use]: The Digital LED tachometer with standard size external appearance adopts the latest A/D conversion chip and the high stability benchmark IC, its electronic chip component has reasonable circuit design, convenient to install [Input Pulse Signal]: NPN/PNP open collector, contact switch, contactless switch, level pulse [Application]: Suitable for all kinds of digital instrument display; The tachometer can be applied to the measurement of voltage, current and external sensor to measure temperature, pressure, displacement and other physical quantities [Great Performance] [Convenient to Use] [Input Pulse Signal] [Application]