- Take the Variable Attenuator from its case and remove the cap from one end of the fiber cable.
- Plug one end of the fiber cable into the output fiber port of a fiber splitter or fiber transmitter.
- Remove the cap from the other end of the fiber cable and plug it into a fiber meter.
- Observe the readings on the fiber meter as you turn the adjustment knob on the fiber cable counter-clockwise.
- Adjust the knob until your desired dBm level is reached.