P-alert Plus Tri-axial Network Accelerograph

P-alert+ is an advanced version of P-alert network accelerometer. It is reinforced in device protection to IP67, upgrading CUP computing speed, and increasing internal memory for waveform storage.

P-alert+ embeds with Pd technology developed by Prof. Yih-Min Wu of National Taiwan University (NTU). Designed to reduce earthquake damages and by Pd technology, Palert+ can determine a seismic event within 3 seconds after P waves are first detected and issue warnings depending on that estimated S waves are devastating or not. P-alert+ provides three triggering algorithms: Pd, PGA, and STA/LTA. Pd algorithm was developed by Prof. Wu as it is described above. PGA stands for Peak Ground Acceleration. P-alert offers 10Hz, 20Hz and 40Hz low pass filters which are user configurable to filter out high frequency noise generated by non-seismic vibrations. In addition, the conventional STA/LTA algorithm is available in P-alert+, too.

Intensity scales for MMI US, KMA Korea, JMA Japan, CWB Taiwan, and CAE China are available for displaying upon users’ configuration. The event information is stored and ready for acquiring from P-alert+, e.g. triggering time, maximum intensity, PGA in each component and 3-component acceleration in vector. P-alert+ is also equipped with an RTC synchronized by NTP or GPS. The powerful networking capability features streaming real time data to three servers automatically for acting as a terminal device for earthquake early warnings and executing emergency shutdown procedures to other devices.

Application

• Cost-effective solution for onsite or regional earthquake monitoring and early warning
• Unique P-wave displacement algorithm along with PGA, STA/LTA algorithms
• Supporting real-time outputs of local intensity levels of MMI (US and most of the world), KMA (Korea), JMA (Japan), GBT (Mainland China), and CWB (Taiwan)
• Compatible with Modbus protocol for emergency controls
• Earthquake event log capability
• Supporting network time protocol (NTP) server and client functions
• Built-in web-based graphic user interface (GUI) for easy configuration
• 3 digital outputs (DO) feeding into separate devices or systems

Specification

• Sensor Type : Triaxial MEMS accelerometer, an optional 4th-axial vertical geophone (built-in or externally)
• Measuring Range : ±2g or ±4g (customized)
• Frequency Response : 05~40 Hz, with 10Hz / 20Hz / 40Hz digital filters
• Algorithms : Pd, PGA, STA/LTA
• Data Format : CSV or miniSEED
• Storage : 16GB microSD Card (expandable)
• LCD Display : 2 lines x 20 characters
• ADC : 4 channels @24-bit
• RTC Accuracy : ±60 sec/year, supporting NTP synchronization. GPS model available upon request
• Sampling Rate (SPS) : 50, 100, 200 (user configurable)
• Power Supply : 10-30VDC
• Power Consumption : 2W@12VDC
• Dimension (L x W x H) : 205 x 160 x 80 mm
• Weight : 8 kg
• Working Temperature : -20°C to +70°C