O2 Sensor & Diesel Injectors

We spent some time making an O2 sensor from scratch. And then tested it on a voltage regulator tester. The LED lights flashed from green to yellow to red. Green indicating that there is little voltage in the sensor therefore, detecting a lean mix. Yellow is in the middle so this is where we want the indicator to stay. And red means there is alot of voltage, meaning the mix would be too rich. Also tested some diesel injectors. Testing their atomisation and comparing them to the manufacturer specifications. If atomisation was too high, this could damage injectors because pressure would be too much. If atomisation was too low, this could mean not enough fuel being injected resulting in low engine power.