Cleveland Family Study

17.8.3.2 Measure for Electrode Sites

• Distance measurements are done with a metric tape measure, and taken in centimeters (cm) and millimeters (mm). When computing percentages to find the electrode site a quick measurement guide can be found below, as well as in the Equipment Maintenance Section. The guide can be photocopied and kept with your prep materials for handy reference.
• All marks on skin must be done with a non-toxic, non-permanent implement, such as a wax-based china marker. Bright blue is most easily seen against dark hair. Red can be misidentified as blood by the participant or family members.
• When working with participants having long or thick hair, create a part in the hair by means of a comb or the unpadded end of a cotton-tipped swab; then hold the hair in place with hair clips while you work.
• The skin must be visible at the electrode sites because the electrode must rest on the skin, not on hair.
• All scalp electrode sites are determined by creating 2 lines that intersect. The electrode is placed over the point at which the 2 lines cross.