Engineering summary
Step-by-step accelerograph installation inside a building: site selection, floor, wall and ceiling mounting with proper bolts, GPS antenna placement, cabling, power and testing.
In short: Accelerograph installation inside a building starts with a site near the structural core, away from HVAC and machinery, ideally bolted level to the floor in a NEMA enclosure with 1 ft (0.3 m) of clearance. Place the GPS antenna with a clear sky view at a window or outdoors, route its cable without sharp bends, power through a grounded surge protector, then verify GPS lock and test recording.
Overview
This guide outlines the comprehensive steps for installing an accelerograph and its accompanying GPS antenna within a building structure. It covers mounting procedures, necessary clearances, and accessibility considerations to ensure optimal performance and ease of maintenance.
Tools and Materials Required
- Drill and drill bits
- Mounting brackets and hardware (screws, anchors, etc.)
- Screwdriver
- Level
- Measuring tape
- Cable conduits (if necessary)
- Sealant (for outdoor installations)
Pre-Installation Planning
- Location Selection: Choose a location that minimizes vibrations from non-seismic sources (e.g., heavy machinery, and HVAC systems). Ideally, the accelerograph should be positioned close to the building’s structural core. It is better to install it on the floor inside an NEMA enclosure.
- GPS Antenna Placement: The GPS antenna requires a clear view of the sky to maintain satellite communication. It should be placed on or near a window sill or mounted externally with a clear path to the sky, avoiding obstructions such as tall buildings or heavy foliage. The GPS provides absolute timing to the instrument for time-stamping of the waveforms recorded.
- Accessibility: Ensure the installation site is easily accessible for maintenance and data retrieval. An access panel or removable ceiling tiles are recommended for indoor installations.
- Clearances: Maintain at least 1 foot (~0.3 meters) of clearance around the accelerograph for ventilation and to ensure unobstructed access.
Installation Steps
- Mounting the Accelerograph:
- Use the measuring tape and level to mark the drill point for the mounting anchor ensuring the accelerograph will be level.
- Drill a hole at the marked point and insert the anchor.
- Secure the mounting anchor with a screw.
- Attach the accelerograph to the mounting anchor following the manufacturer’s guidelines.
Example of floor mounting
In the following picture, you can see a floor-mounting installation of a unit with an internal sensor with the use of a bolt in the concrete.
Drawing is courtesy of SARA
The leveling pads do not necessarily need the counter-lock paddle (not drawn in the figure), even if it is always good to have. They would work in a counteraction, so the paddles shall be adjusted forcing the sensor to go up, while the bolt keeps it fixed down.
Photo is courtesy of SARA
The same principle will work for wall and ceiling installations as follows.
Example of wall mounting or ceiling
If the unit needs to be mounted in buildings, it often requires a vertical or ceiling-flipped installation. In these cases, is essential to use the central key-hole hooking slot.
Drawing is courtesy of SARA
In both cases, especially for mounting equipment over 1 meter of elevation we absolutely recommend the use of a safety chain or steel cord.
It can be anchored to any suitable threaded hole. If necessary and appropriate you may decide to use 2 or more threaded holes to anchor the safety cord.
All safety retention devices must be checked every year. To be on the safer side a shaft or a large steel baseplate could be used instead of the use of a dowel.
Appropriate heavy-load dowel and proper bolt are necessary to anchor this way, also depending on type of material the wall is made of, concrete, bricks, etc.
The bolt head should be of 12 mm, maximum of 14 mm to allow a proper leveling degree of freedom. The diameter of bolt stem should be not less than 8 mm for wall or ceiling mounting.
NOTE – 1: It is very important to have a safety bonding for the wall and ceiling mount and check the tightness of it periodically else vibrations will be wrongly measured.
NOTE – 2: Do not overtight the feet else the case will be damaged.
- Installing the GPS Antenna (if applicable):
- If mounting externally, ensure the antenna is positioned securely with a clear view of the sky. Use a sealant to waterproof any drill holes.
- For window placement, ensure the antenna is as close to the glass as possible, avoiding metal frames that might obstruct signal reception.
- Route the antenna cable to the accelerograph, avoiding sharp bends. Use cable conduits if necessary to protect the cable from damage.
- Cabling and Power Connection:
- Connect the GPS antenna to the designated port on the accelerograph.
- Ensure all cables are neatly routed and secured.
- Connect the accelerograph to a power source, using a surge protector. Make sure that the power outlet is grounded.
- Initial Setup:
- Follow the manufacturer’s instructions to power on and configure the accelerograph.
- Verify the GPS connection and perform any required calibrations.
- Testing:
- Conduct initial tests to ensure the accelerograph is recording data accurately.
- Verify that the data can be retrieved and is consistent with expectations.
Post-Installation
- Documentation: Keep a record of the installation details, including the location, date of installation, and any specific configurations.
- Maintenance Schedule: Establish a regular maintenance schedule to inspect the accelerograph, its connections, and the surrounding area to ensure continued accuracy and performance.
Notes
- Always refer to the manufacturer’s installation guidelines for specific instructions related to your accelerograph model.
- Consider local building codes and regulations when installing external components.
- For installations in areas with extreme weather conditions, additional protective measures may be required for the outdoor components.
By following these comprehensive instructions, you can ensure the successful installation of an accelerograph and its GPS antenna within a building, facilitating accurate seismic data collection and analysis.
Questions?
Email us at support@quakelogic.net or call us at +1-916-899-0391.
Key Takeaways
- Install close to the building's structural core, away from heavy machinery and HVAC, preferably on the floor in a NEMA enclosure.
- Keep at least 1 ft (about 0.3 m) of clearance around the unit for ventilation and access.
- Wall or ceiling mounts use the central key-hole slot; bolt head 12 to 14 mm, bolt stem at least 8 mm, heavy-load dowel.
- Above 1 m elevation a safety chain or steel cord is mandatory; check all retention devices every year.
- GPS antenna needs a clear sky view for absolute timing; place it close to the window glass away from metal frames, seal outdoor drill holes.
Frequently Asked Questions
Install the accelerograph close to the building's structural core in a location that minimizes vibration from non-seismic sources such as heavy machinery and HVAC systems. Floor mounting inside a NEMA enclosure is preferred. Keep at least 1 ft (about 0.3 m) of clearance for ventilation and access, and choose a site reachable for maintenance, for example behind an access panel or removable ceiling tiles.
For wall or ceiling installation use the unit's central key-hole hooking slot with a heavy-load dowel suited to concrete or brick. The bolt head should be 12 mm (maximum 14 mm) to leave leveling freedom and the bolt stem at least 8 mm. For mounts above 1 m, attach a safety chain or steel cord to a threaded hole and inspect it yearly. Do not overtighten the feet, and keep the bonding tight so vibrations are measured correctly.
The GPS antenna provides absolute timing for waveform time-stamps, so it needs a clear view of the sky. Place it on or near a window sill as close to the glass as possible, away from metal frames, or mount it externally with no tall buildings or heavy foliage in the way. Seal any outdoor drill holes with sealant and route the cable to the accelerograph without sharp bends, using conduit where needed.
In a floor installation the accelerograph is fixed down by a bolt set in the concrete while the leveling pads are adjusted to push the sensor up against it, working in counteraction to level the unit. Counter-lock paddles are optional but good practice. A shaft or large steel baseplate can replace a dowel for added security. Avoid overtightening the feet, which can damage the case.
After installation, power the accelerograph through a grounded outlet with a surge protector, follow the manufacturer's configuration steps, confirm the GPS connection and run any required calibration. Record test data and verify it can be retrieved and looks as expected. Document the location, date and configuration, and set a regular maintenance schedule to inspect the unit, its connections and the mounting.
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Topic cluster
Related engineering knowledge areas
- Structural Health MonitoringMonitoring for bridges, buildings, dams, tunnels, industrial facilities, and resilient infrastructure.
- Earthquake Early WarningOn-site detection, alerting workflows, seismic switches, and critical infrastructure warning systems.
- Seismic SensorsSeismometers, accelerometers, geophones, sensor selection, calibration, and field deployment.
- Infrasound MonitoringLow-frequency acoustic sensing for environmental noise, blast, UAV, volcano, and defense applications.
Definitions and references
Terms, standards, and source cues
- SHM: related to Structural Health Monitoring in this QuakeLogic knowledge cluster.
- damage detection: related to Structural Health Monitoring in this QuakeLogic knowledge cluster.
- earthquake early warning: related to Earthquake Early Warning in this QuakeLogic knowledge cluster.
- seismic switch: related to Earthquake Early Warning in this QuakeLogic knowledge cluster.
- seismometers: related to Seismic Sensors in this QuakeLogic knowledge cluster.
- accelerometers: related to Seismic Sensors in this QuakeLogic knowledge cluster.
- infrasound sensors: related to Infrasound Monitoring in this QuakeLogic knowledge cluster.
- low-frequency noise: related to Infrasound Monitoring in this QuakeLogic knowledge cluster.
Standards mentioned
- ASCE 7 seismic design/site-classification references
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