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Earthquake detectors


When they detect earthquake vibrations (P waves or S waves) larger than the set acceleration (gal), they automatically activate and turn on an electric circuit. They are activated in combination with a control circuit for equipment such as elevators and general equipment in the event of an earthquake to stop equipment in a controlled way and issue alarms.
[Cumulative shipments: Over 100,000]


- They hardly ever erroneously determine an earthquake has occurred because they use microcomputers.

- They have internal batteries so they can work during a power outage.

- You can reset and check their operation by remote operation using contact signals.

- Three optional levels of acceleration are settable.


Principle of operation

This product uses our original triaxial capacitance acceleration sensor as an acceleration sensor. Additionally, it consists of a microprocessor, an output unit, a power supply, an indicator and an operation switch unit. Signals are sent from the acceleration sensor to the microprocessor, they go through the earthquake frequency range limiting filter, and they are compared with the preset detection level and if necessary a relay contact is then activated.

- P wave detection type, S wave detection type

- P and S waves simultaneous detection type

New product (patent pending)
- Waterproof P wave detection type

Use for elevators

Our earthquake detectors interlock with the control circuit of an elevator to ensure the safety of users in the event of an earthquake.

They detect P waves (minor initial tremors) that come first in the event of an earthquake. When the earthquake detector receives control signals from the sensor, it stops the elevator on the nearest floor if the elevator is moving. Also, it lets the occupants evacuate from the elevator before the S waves (main tremors) arrive. After that, it can maintain an off-service state (for a set time) or cancel it according to the detected S waves and the acceleration (earthquake intensity) preset in the detector. This operation can prevent secondary accidents caused by people using elevators after an earthquake. The Ministry of Land, Infrastructure, Transport and Tourism mandated the installation of such detection systems in new elevators. This ministry has been strengthening the guidance on existing elevators too.

Detailed Specifications (PDF)

Instruction Manual (PDF)

Catalogue of Earthquake Detectors (PDF)


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The price differs depending on the settings and specifications. Please ask us for details.

Long-period ground motion detector (long object-swing detector)

We have developed a long-period ground motion detector (long object-swing detector) for skyscraper buildings, towers (elevators), etc.

*What is long-period ground motion? -(WikiLinks)