Check Your Experimental Setup
Successful instrument calibration means that the instrument and its cable are most likely not causing your problem. Here is a list of the most common experimental setup issues that you can check:
1. Verify the correct cell connections to the sample.
Your Gamry Potentiostat requires the Blue and Green leads to be connected to the working electrode, the White to the reference electrode, and the Red to your counter electrode (for a standard 3-electrode experiment). See our App Note entitled 2, 3 and 4-Electrode Experiments, for a detailed discussion of connections schemes for experiments.
2. Test for a bad reference electrode.
A high impedance Reference Electrode will cause problems that range from simple overloads to potentiostat oscillation. The simplest check for a reference electrode problem is to disconnect the electrode, and clip the white lead onto the counter electrode alongside the red lead. This 2-electrode configuration bypasses the reference electrode to see if the experiment regains stability.
With the EIS300 software package you can directly measure the impedance of the reference electrode. Use our App Note: Checking the Impedance of your Reference Electrode.
3. Verify that a ground loop is not created.
Your Gamry Potentiostat is fully floating (isolated from Earth ground). This is a requirement for use in experiments where any electrode is grounded (autoclaves are a good example). If this is the case your potentiostat cannot be Earth grounded or you will have very noisy, innaccurate results. Be sure the grounding post on the back of your instrument is not connected to Earth ground.
4. Check for valid experimental parameters.
Check to make sure that your experiment parameter values are correct. Pay careful attention to Scan Rate (mV/s), Sample Period (s), Step Size (mV) and Max. Current (mA). Incorrect settings of some of more of these parameters can cause the potentiostat to overload or be unstable. Contact Gamry if you need help with experimental setup.
Still having problems during your experiment?