Section 771 Of Article 3. Equipment, Practices, And Facilities From California Public Utilities Code >> Division 1. >> Part 1. >> Chapter 4. >> Article 3.

. The commissioners and their officers and employees may enter upon any premises occupied by any public utility, for the purpose of making the examinations and tests and exercising any of the other powers provided for in this part, and may set up and use on such premises any apparatus and appliances necessary therefor. The agents and employees of the public utility may be present at the making of such examinations and tests.