GL-PA4
Digital Strong-motion Accelerograph
Main application fields:
1. Strong earthquake observation in free field;
2.Strongvibrationobservationofimportantbuildings,structuresand facilitiessuchashydropowerstationdamandnuclearpowerstation testing and health monitoring;
3. Observation of manual blasting;
4. Vibration monitoring of dams, Bridges, stations, tunnels and other facilities;
5. Site seismic safety assessment;
6.Emergency mobile earthquake observation,earthquake scientific investigation,earthquake early warning and monitoring,landslide and rockfall monitoring;
OVERVIEW
Description
The GL-PA4 is an integrated seismic observation instrument combining multiple functions including acceleration sensing, data acquisition, storage, transmission, and detection. It contains a 24-bit data acquisition unit, a force-balanced accelerometer, a data storage module, network communication capabilities, and a GNSS time synchronization unit. The force-balanced accelerometer detects triaxial vibration acceleration signals and converts them into proportional voltage outputs for vibration measurement. Comprising three independent orthogonal sensors acquisition unit processes voltage signals from these sensors via three high-resolution, wide-dynamic-range channels that deliver real-time data streams with ultra-high synchronization accuracy. It supports multi-sampling rates, achieving 138dB dynamic range at 50-point sampling. The unit features a large-capacity industrial-grade CF card storage for long-term recording of continuous data, event data, and calibration data. For detailed strong-motion calibration, it records seismic calibration data at 500-point sampling rate. Multiple sampling rates can be transmitted in real-time via network to the seismic network center. Additionally, the triaxial digital strong-motion accelerometer adopts a highly integrated design, offering compact size, lightweight construction, and low power consumption. Data transmission employs low-latency real-time streams with multi-connection support and FTP data download capabilities.

Technical Parameter
Sensor
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Structure: three-way integration, force balance electronic feedback
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Range: ±4g
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Bandwidth: DC-280Hz (-3dB); Dynamic range: more than 150dB
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Nonlinearity: better than 0.1%
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Horizontal sensitivity: better than 1%
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Output: ±9.3467V (both ends)
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Vibration: <500 µg/℃
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Adjustment zero: manual
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Damping calibration: Yes
Collector
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ADC: 24 bits
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Dynamic range: greater than 135dB@100sps
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Sampling rate: 50sps, 100sps, 200sps, 500sps
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Digital filter: linear phase FIR / minimal phase FIR
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Distortion: better than -100dB
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DAC: 16 bits, maximum output current ±5mA
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Calibration signal type: pulse, sine wave optional, support damping free strong earthquake calibration
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Start mode: timing, instruction
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Interface: LAN Ethernet, WiFi (support parameter setting, data browsing)
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Data communication protocol: low delay real-time data network service (Jopens, TCP/IP, FTP)
Overall Machine Performance
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Timing: GNSS timing unit / IRIG code input
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Time synchronization error: less than 0.01ms
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Clock stability: better than 0.5ppm
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Output sensitivity: 32000 count/gal (2384 µV/gal)
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Power supply: +12V (9V~20V)
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Storage environment: -55℃~80℃
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Working environment: temperature -40℃
60℃, humidity 0100% -
Storage medium: 8G/32G/64G/128G industrial wide temperature CF card
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Recording method: event trigger recording, continuous waveform recording
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Data format: EVT, mini SEED, GEOPEN
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Remote monitoring: parameter setting, working status monitoring
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Size and weight: φ139mm×154mm, 2.76kg















