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.
- 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.
- Try applying a slight pressure on the sponge holders.
Long hair can also cause this problem. In this case, 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.