Common Problems

1. The plot shows no peak/dip.
   • Check the PIN diode and light, make sure there is enough light.
   • If the PIN diode signal amplitude is above 100 mV already, try changing the Lock-in Amplifier phase by 90$^\circ$.
   • If still no peak is detected, try changing the start sweep frequency and the number of steps such that the program will cover larger region.

2. The plot shows multiple peaks. It might be the signal is mixed with background (cable resonance, noise etc.). The solution might be complicated and will not be discussed here. Contact target experts on call.

3. How do I use the output data? The data is saved in a text file consisting of two columns. The first column contains the frequency of the EPR coil, while the second column holds the corresponding signal from the Lock-in Amplifier. Its format can be read by programs such as SigmaPlot, Excel, and Paw.