Impedance

To measure the impedances of your Mentalab Explore electrodes, navigate to the Impedance Measurement page.

Select which type of electrodes you are using from the drop-down menu. Then, click on ‘Measure Impedances’. For wet electrodes, channel impedances will display their value and corresponding color code as in the table below. Good dry electrode impedances are less than 100kΩ for flat electrodes placed on bare skin, and less than 300kΩ for brush electrodes placed on hair. See our guidelines on improving impedances for more information.

Color	Range (kΩ)
	Wet electrodes
Green	< 10
Yellow	10 – 20
Orange	20 – 30
Red	30 – 50
Black	> 50
Gray	Inactive channel / Device not connected

You can also visualize impedances on an EEG montage. For this, make sure you assign all channels names in the standardized location in settings page from dropdown menu. Then, switch to impedance page and change toggle button on top right to EEG view.

EEG montage view — Visualize impedance values on EEG montage

Impedance values depend on the impedance of the reference electrode. The value shown for each electrode is the average of the ground and ExG electrodes’ impedances.

If all channel impedances are high, try cleaning the skin under the reference electrode more thoroughly using, e.g., alcohol, abrasive gel, or EEG.

Impedance values are subject to environmental conditions like noise and temperature. Aim for regular room temperatures (~15-25°C)

For more information or support, do not hesitate to get in contact at: support@mentalab.com