knock sensor

To test this sensor I had to hoock it up to a oscilloscope and gently tap the end of the sensor and observe the waveform.It took me a long time to get the osciliscope set up perfectly because i was reading it to fast and when i changed it was to slow and cooldnt get a good reading.it gets a voltage reading even though it wasnt hoocked up to a supply.the reasone for this is beacuse it has crystals inside it caled peso crystals and when they move around and hit when you hit the sensor and it causes a voltage

This is what my wafe form loocked like after i taped the sensor against the desk.You can also see a good picture of the actual sensor in his hand.This patern also shows that this is a good knock sensor because a bad sonsor wont give a complete patern like this one because it wont have a voltage.A knock sensor Iis the sensor that makes you hear the pinging noise that your car makes when timing is wrong or runing the wrong octane fuel for your car.