Maintenance & Servicing of Earthquake Recording Instrumentation in Buildings
TECHNICAL BULLETIN
BLDG-16-1
June 2026
IN THIS BULLETIN:
The purpose of this technical bulletin is to establish the maintenance and servicing requirements for the Earthquake Recording Instrumentation required by Appendix Chapter L of the California Building Code (adopted by Municipal Code Section 145.0107 (e)) or when required as a condition of approval when a non-linear response history procedure is used in the design of a high-rise building.
Refer to SDMC 145.37 for local modifications and additions to appendix chapter L “Earthquake Recording Instrumentation” of the California Building Code”.
Installation of a recording system that meets the requirements in California Geological Survey (CGS) System Requirements for structural systems will result in the California Strong Motion Instrumentation Program (CSMIP) agreeing to provide long term monitoring of the recording system to verify correct operation.
Required earthquake recording instrumentation equipment shall be serviced and maintained in proper working condition to provide measurements during seismic events. The installation, servicing or removal of the instrumentation shall be done by a maintenance agency authorized to do so by the manufacturer of the equipment.
I. Maintenance & Servicing
The building owner shall maintain an on-site logbook documenting all on-site maintenance and services.
The maximum service interval shall not exceed one year. If the instrumentation is inoperative during service inspections, a reinspection and servicing shall be required at least semiannually until the problem is corrected. The authorized maintenance agency shall determine the shorter period so the instrumentation is continually operative.
Upon completion of the maintenance/servicing, the building owner shall certify in writing to the Building Official that the equipment is in operating order.
For instrumentation systems monitored by CSMIP, CSMIP will monitor and report on the apparent health of the recorder, accelerometers and displacement sensors.
Other sensors will also be monitored and apparent health reported if the building owner or representative provides information on the characteristics of the signal produced by the sensors in their operational and failed states. CSMIP will perform periodic state-of-health checks and functionality tests remotely via the provided phone line and notify the building contact person and the Building Official when any repairs are needed.
II. Out of Service Repairs
Where the instrumentation maintenance agency finds that the instrument must be removed from the building for repair, the instrument shall be returned and made operative as soon as possible but not exceeding 60 days from the removal date.