EQR-120: High Dynamic Range Strong Motion Accelerograph
EQR-120: High Dynamic Range Strong Motion Accelerograph
EQR-120: Class B Rated. Research-Grade in Practice.
128 dB dynamic range (0.1–20 Hz) and 31-bit resolution, at the density real structural monitoring needs.
Summary
The EQR-120 is a research-grade accelerograph in one box, built on 20 years of MEMS development.
Canterbury Seismic has built MEMS accelerographs from the start, and its servo, closed-loop MEMS sensor now reaches 128 dB of dynamic range across 0.1 to 20 Hz in a single compact instrument: precision sensor, 31-bit digitiser, recorder, precision timing and a built-in web server. Engineered for purpose, it is quiet enough to capture ambient structural vibration for modal analysis and strong enough to stay on scale through a major earthquake, so one install does two jobs, on a single point, a whole structure or an entire array.
Description
Every EQR-120 delivers credible, defensible data with sub-microsecond GNSS and PTP timing. It is the standard that holds up when the data is actually needed, in an insurance claim, a post-event review, or a consent process. Its 128 dB dynamic range (0.1–20 Hz) means one instrument does two jobs: capturing ambient structural vibration for modal analysis, and staying on scale through a major earthquake. One install, both datasets.
Flexible array-wide timing
Any EQR-120 in an array can act as the PTP timing master. Equip a single unit with GNSS wherever sky visibility allows, and every other unit, regardless of location, including units mounted deep inside a structure, a dam abutment, or a tunnel, receives sub-microsecond timing over PTP. No antenna required at every sensor.
Native integration
The EQR-120 connects directly into the EQResponder Central Recorder (EQR-C), coordinating two or more units, or a mix with LVDTs and weather sensors, into one synchronised, time-aligned dataset.
Better together: EQR-120 and the Central Recorder
Individually research-grade. Combined, a fully synchronised structural array, with no GNSS antenna constraints.
A single EQR-120 already delivers research-grade data on its own. Connect two or more into an EQR-C array and the relationship between sensors becomes the data, not just each sensor's individual reading.
The Central Recorder coordinates up to 16 units, EQR-120s or a mix with LVDTs and weather sensors, to microsecond precision, triggers the whole array from a single event, and writes it all to one coherent file, in standard formats with no proprietary software to license. Because any unit in the array, including the EQR-C itself, can act as the PTP timing master, only one GNSS antenna is needed across the entire deployment, placed wherever sky visibility is easiest. Every other instrument, including units mounted deep inside a structure, receives the same sub-microsecond timing over PTP.
For structural arrays where the relationship between sensors matters as much as any single reading, isolator displacement alongside roof and base acceleration, for example, this is the difference between data you can confidently analyse and data you have to forensically reconstruct after the fact.
EQR-90 units integrate natively into the same Central Recorder architecture, so a single array can combine dense EQR-90 coverage with EQR-120 precision at key locations, all on one synchronised clock.
Full Technical Specification
Accelerometer
- Type: 3 x uni-axial MEMS servo silicon accelerometers
- Range: ±4g
Dynamic Range and Signal Quality
- Dynamic range: 128dB (0.1–20Hz), 120dB (0.1–100Hz)
- Offset error: <±0.02% over operating temperature range
- Linearity: <±0.1%
- Gain error: <±0.08% over operating temperature range
- Integral non-linearity: <0.0004% (full range)
- Resolution: 31 bits
- SNR: 130dB (200Hz), 133dB (100Hz), 136dB (50Hz)
A/D Conversion and Signal Processing
- Sampling: Zero-skew autonomous sampling, 1ppm time-base (0–60°C)
- Anti-alias: 1-pole RC filter (fc = 10kHz)
- A/D type: 24-bit Sigma-Delta
- Sensor data output rate: 50Hz, 100Hz, 200Hz
- Filtering: FIR digital anti-alias filter/decimator, linear phase
- Measurement bandwidth: DC to 20, 40, or 80Hz
- Recorded dynamic range: 130dB (80Hz BW), 133dB (40Hz BW), 136dB (20Hz BW)
Timing
- Type: Synchronised to UTC. Internal GPS, NTP, IEEE 1588v3 PTP (master or slave), backup real-time clock
- Accuracy: <1µs UTC with GPS lock or PTP, <5ms typical via NTP, 50ppm on backup RTC alone
Communication
- Type: Integrated LAN, external 3/4/5G cellular modem, Wi-Fi via USB or Ethernet
- Protocol: TCP-IP
- Services: TLS-encrypted HTTPS web server, programmatic HTTPS API, SeedLink, email outputs
Triggering
- Type: Trigger recordings based on PGA or channel value, trigger transmission to EQResponder Central Recorder array management systems
- Pre-trigger filter options: 0.1Hz or 1.0Hz high-pass, 5.0Hz, 10.0Hz, or 20.0Hz low-pass, or any band-pass combination
- Absolute level: Independent thresholds on each channel, selectable AND/OR channel triggering
- Pre-event length: 10 to 60 seconds
- Post-event length: 10 to 600 seconds
- Relay output upgrade (option): up to 2 solid state relay outputs, latching or non-latching, active high or active low
Data Storage
- Format: MiniSEED, CSV (compressed or uncompressed), JSON metadata file
- Metadata: Flash disk, PGA, peak channel accelerations, trigger duration
- Storage: 32GB MLC flash disc (SLC option), triggered/continuous data, SeedLink ring buffer >90 days
User Interface
- Type: Desktop/tablet/mobile browser compatible web server, Windows/macOS/Linux supported
- Features: Parameter configuration, live data and diagnostics display, data downloads, mapping
Power
- Input range: 10.5 to 30.0V DC
- Typical consumption: 5.5W at 13.8V input
- External battery/UPS: 12V SLA, 7.0Ah, 16-hour runtime with plug-pack 230VAC to 13.8VDC charger (option: 24V SLA compatible)
Size
- Dimensions: 140 x 84 x 85mm
- Weight: 1.0kg
Environmental
- Housing: Aluminium case, IP54 rated, IP65 rated enclosure option
- Temperature range: -10°C to +60°C standard, non-condensing (-40°C to +60°C option)
- Mounting: Separate mounting plate with level adjustment and protective dust cover, IP65 rated enclosure option
Warranty
- 1 year standard, extended option up to 6 additional years