Washington Administrative Code
Title 434 - Secretary of State
Chapter 434-261 - Counting center procedures
Section 434-261-108 - Random check of ballot counting equipment

If a random check of up to six batches of ballots is conducted pursuant to RCW 29A.60.170 in a county that uses optical scan voting equipment, each batch must be tabulated on a different scanner if more than one scanner is used in the election. If there are more scanners used in the election than batches to be checked, then the scanners must be selected at random.