Earthquake Recording Instrument (ERI) in the Philippines

An earthquake recording instrument (ERI) is an accelerograph that records how a building shakes during an earthquake. USHER ERI Max is a Filipino-made ERI, paired with a web portal that turns that data into alerts and reports.

USHER ERI Max earthquake recording instrument

What is an earthquake recording instrument?

An earthquake recording instrument (ERI) is an accelerograph: a sensor that measures ground and structural acceleration and stores the record of strong shaking. Engineers use that record to understand how a structure actually responded, instead of guessing from damage alone.

In the Philippines, the DPWH Guidelines and Implementing Rules on Earthquake Recording Instrumentation for Buildings implement Section 105.2 of the National Structural Code of the Philippines (NSCP 2010). They set which buildings must have an ERI and what the instrument must do.

Which buildings need an ERI under DPWH rules?

The rules apply in Seismic Zone 4, which is the entire Philippines except Palawan and Tawi-Tawi. Under Table 1 of the DPWH rules:

  • Buildings above 50 meters, government or private: at least 3 accelerographs (ground floor or lowest basement, middle floor, and the floor below the roof)
  • Government hospitals, schools, and other buildings above 50 meters: at least 3 accelerographs
  • Hospitals with 50 beds or more, and schools with 20 classrooms or more and at least 3 storeys: 1 accelerograph at the ground floor or lowest basement
  • Provincial, city, and municipal halls and buildings: 1 accelerograph at the ground floor or lowest basement
  • Commercial buildings with occupancy of at least 1,000 persons or gross floor area of at least 10,000 square meters: 1 accelerograph
  • Industrial buildings with occupancy of at least 1,000 persons and gross floor area of at least 10,000 square meters: 1 accelerograph

Table 1 applies to buildings in cities and municipalities within a 200-km radius of a Type A fault. For buildings outside that radius, a single accelerograph at the ground floor or lowest basement may be installed. The DPWH rules are the authority; confirm what applies to your building with your Building Official.

What the DPWH requires of the instrument

The DPWH specifies minimum requirements for the accelerograph itself:

  • Seismic-qualified, as tested by a recognized international testing laboratory
  • Fault detection and real-time alarm information (audio, visual, or both) during an earthquake
  • Internal battery backup for continuous operation through power fluctuations
  • Where applicable: three components (vertical, longitudinal, transverse), DC to 100 Hz bandwidth, 2g sensitivity, IP67 environmental protection, and a 10-year minimum design life
  • Recording at a minimum of 100 samples per second with a 16-bit converter, GPS or NTP time, and Ethernet communication (TCP/IP, FTP/SFTP)

Installation, maintenance, and compliance

Installation is supervised by a Certified Civil/Structural Engineer and verified by the Building Official. For newly constructed buildings, installation is part of the requirements for the Certificate of Occupancy. For existing buildings, installation and operation form part of the Annual Certificate of Inspection.

The supplier must guarantee a maintenance period of at least 10 years, with a maximum service interval of one year and yearly calibration testing. After an earthquake of magnitude 6 or greater, the owner must retrieve the data and have it interpreted by a Certified Civil/Structural Engineer for submission to the DPWH. The DPWH also prohibits mixing seismic equipment parts from different brands, so the system should come from one supplier.

USHER ERI Max

ERI Max is USHER's flagship system: a high-precision accelerograph integrated with a web portal, designed to meet the DPWH guidelines and implementing rules on earthquake recording instrumentation and the NSCP. USHER is a Filipino-made ERI, with local support.

  • Real-time monitoring and analysis through the USHER Portal
  • Built for buildings, bridges, and critical infrastructure
  • Developed and made in the Philippines by USHER Technologies Inc.

ERI Max or USHERette?

USHERette is a palm-sized, lower-cost version built on an accelerometer and gyroscope, designed for residential buildings and smaller structures. ERI Max is the choice for buildings and infrastructure that need the full instrument.

Frequently asked questions

What is an earthquake recording instrument (ERI)?

An ERI is an accelerograph that records the acceleration of a building or ground during an earthquake, so engineers can assess how the structure responded.

What are the accelerograph requirements in the Philippines?

The DPWH Guidelines and Implementing Rules on Earthquake Recording Instrumentation for Buildings, which implement Section 105.2 of NSCP 2010, require the accelerograph to be seismic-qualified, to have fault detection, real-time alarm information, and internal battery backup. Where applicable it should also have three components, DC to 100 Hz bandwidth, 2g sensitivity, IP67 protection, recording at 100 samples per second or more, and GPS or NTP timing. Buildings above 50 meters need at least three accelerographs.

Which buildings need an earthquake recording instrument?

In Seismic Zone 4 (all of the Philippines except Palawan and Tawi-Tawi), the DPWH requires them in buildings above 50 meters (at least 3 accelerographs); hospitals with 50 beds or more and schools with 20 classrooms or more and at least 3 storeys; provincial, city, and municipal halls; commercial buildings with at least 1,000 occupants or 10,000 square meters of floor area; and industrial buildings with at least 1,000 occupants and 10,000 square meters. Confirm what applies to your building with your Building Official.

Is an earthquake recording instrument required in the Philippines?

For the building types listed in the DPWH rules, yes. For newly constructed buildings, installation is part of the requirements for the Certificate of Occupancy. For existing buildings, installation and operation form part of the Annual Certificate of Inspection.

How long must an ERI supplier provide maintenance?

The DPWH rules require the supplier to guarantee a maintenance period of at least 10 years, with a maximum service interval of one year and calibration testing each year.

What must be done after a strong earthquake?

After an earthquake of magnitude 6 or greater, the Building Official requires the owner to retrieve the ERI data and have it interpreted by a Certified Civil/Structural Engineer. The data and interpretation are submitted to the DPWH.

Is there a Filipino-made earthquake recording instrument?

Yes. USHER ERI Max is a Filipino-made earthquake recording instrument and structural health monitoring system, developed by USHER Technologies Inc., a Mapúa University spin-off co-funded by DOST-PCIEERD.

What is the difference between an accelerograph and a seismometer?

A seismometer is a sensitive instrument built to detect weak ground motion, including small or distant earthquakes. An accelerograph records strong shaking as acceleration, which is what engineers need to see how a building was stressed. That is why an earthquake recording instrument for buildings is built around an accelerograph.

Can an ERI predict earthquakes?

No. An ERI records shaking as it happens. It does not predict earthquakes; its value is in telling you how your building behaved so you can decide on inspection and repairs quickly.

How do I request an ERI installation or demo?

Use the contact page or email inquiries@usher.ph.

Sources and coverage

Related