Specifications include, but are not limited to: 8. QUARTERLY MAINTENANCE A. A logbook will be kept on site for each piece of equipment to be maintained by the technician. The log shall contain the dates each quarterly maintenance was performed. . B. The frequency of quarterly maintenance shall be no more than ninety (90) days between services. C. The Contractor will be required to call the Area office and make an appointment to perform the quarterly maintenance at least three (3) days in advance. Contractor will check in with Area office upon arrival and check out when the work is completed. If there are any discrepancies on the invoice concerning hours worked, the CHP will refer to sign in sheet to confirm actual hours at facility.