Which type of electrode would typically exhibit lower impedance when properly placed?

Disk electrodes typically exhibit lower impedance when properly placed due to their design and surface area. Disk electrodes have a large, flat contact area, which enhances their ability to transmit electrical signals with minimal resistance. The larger contact area allows for better coupling with the skin, reducing the air gap that could increase impedance. Proper placement further ensures that the electrode is in full contact with the skin, optimizing the signal quality and reducing variability caused by movement or improper application.

Surface electrodes, while effective for many applications, may not consistently achieve the same low impedance levels depending on the type of adhesive used and the condition of the skin. Needle electrodes tend to have higher impedance due to their smaller surface area and the potential for tissue resistance. Subdermal electrodes, while effective for deep measurements, might not provide the same benefits as disk electrodes in terms of surface contact and impedance management.