DollaTek DC 8-24V 4 Digital LED Tachometer RPM Speed Meter with Hall Proximity Switch Sensor NPN 10-9999RPM

• The speed panel meter uses the latest A / D converter chip and high stability reference IC. Good stability, high precision and strong anti-interference ability.
• The external appearance takes standard size and is easy to install. Wide range of applications including voltage, current and external sensor measurements to measure temperature, pressure, displacement and other physical quantities. Suitable for all types of digital instrument displays.
• Input pulse signal: NPN / PNP open collector, contact switch, contactless switch, level pulse. Input signal voltage: low level: -30V -0.6 V, high level: 4-30V.
• The LED display has two choices: red and blue, four-digit precision display, display update rate, real-time update at a rate of more than three times per second.
• Measuring range: Frequency: 9999Hz, 999.9 HZ, 99.99 KHZ, automatic switching selection. The automatic range selection saves the user time and effort. Efficient completion of the work.

Specifications: Measurement accuracy: ± 0.1% Display mode: 0.56 "LED Display update rate:> 3 times / sec Working power supply: DC8-24V, 30mA, measuring range: 10-9999RPM Hall proximity switch: magnetic Appearance size: 80 x 42 x 25 mm / 3.14 x 1.65 x 0.98 inches LED display (optional): red, blue Weight: 80g (red), 105g (blue) Overrange display: The first display shows "1" or "-1" and the last three are not displayed Precautions: 1. If strong electromagnetic interference is to be avoided, it is better to use shielded wires or double rope wires to measure conductors 2. The count signal of the counter and the switches of the zero clear signal input or the circuit must be as close as possible to the terminal of the counter in order to make the signal line as short as possible 3. Avoid using others like: high voltage wires or power cables and so on with the same tube or twisted track line to avoid unnecessary interference. If necessary, please use the shielded wire, shielding layer connect the "+" of the counting terminals 4. It is not recommended to use a mechanical switch or microswitch as these have a relatively short life and can be erroneously counted after a long time. If you use a mechanical switch or a microswitch, please try to use a better quality so as not to be misunderstood and suggest a magnetic control switch Delivery content: 1 x speedometer 1 x Hall NPN proximity sensor