Review on 🔢 DIGITEN 4-Digit Green LED Tachometer with RPM Speed Meter and Hall Proximity Switch Magnet Sensor NPN, Ideal for Lathe and Conveyor Belt Applications by Rob Dixon

The first came without the plug and wire connecting the block to the sensor, but due to health reasons I didn't realize this until after the return period. I have ordered a second one. It arrived full but refuses to read the RPM. The documentation and notes on the website say it runs on 9V and in fact recommend using a 9V battery for testing. However, in the depths of the limited documentation it says that you should read 12V on one of the wires. I have ordered a 12v power adapter and will be posting it once it arrives. Looks like the problems were in the first block. The reading LED was missing a cable connector and the transmitter unit was defective. When I got the second block it still didn't work. Then I turned on the read LED and still didn't go. I didn't replace the gear unit because it was installed on a lathe. When I disconnected the transmitter everything worked as it should.