Take a look at our YouTube tutorial on how to mount the cap properly:
Here are a few suggestions that may help lower the impedance values:
- The chin strap should go around the chin, not bellow. This helps improving the contact, and hence the impedance values.
- Try applying a slight pressure on the sponge holders. You can do this with more electrodes at the same time by applying pressure with your entire palm.
- You can re-wet the sponges in locations that are showing the higher impedance values than desired. To do this, after the cap is mounted, you can take out the sponges with high impedance, immerse them in the saline solution and return them to the cap.
- If the previous does not help, you can additionally scrub the skin under the sponge using a cotton swab with saline.
- In extreme cases - very thick hair, try using a cotton swab with saline to push aside the long hair and re-wet the scalp before inserting the sponge holder with the sponge.
Lastly, make sure you've correctly made the solution and left the sponges to soak for the appropriate amount of time - How to prepare saline solution and prepare semi-dry sponge caps