What is an impedance check?

An impedance check will ensure that there is a good connection between the electrodes and the skin to proceed with cortical testing.

What do the colours on the impedance check represent?

The colours shown on each of the bars for each electrode represents how good the electrode connection is:

  • Green: [0 – 5 kΩ], good impedance
  • Yellow: [5 – 10 kΩ], satisfactory impedance
  • Marginal: [10 – 15 kΩ, marginal impedance
  • Red: > 20 kΩ, poor impedance
How can I check the impedance after I have gone through the client selection process?

Open the Tools menu, point at Utilities, and select Impedance Check. This will display the Impedance Check window. Impedances can also be checked during a recording when pausing the recording first.

What happens if I have rescrubbed the Cz (active) and reference electrode and no improvement in the impedance?

It might be possible that one of the electrode connectors has lifted slightly from the Electrode Processor. If this is not the case, check the ground electrode (forehead) as all electrodes are referenced to this electrode and it could be impacting on your impedance measurements at Cz and mastoids.