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DBT59-2015 PDF EnglishSearch result: DBT59-2015
DBT59-2015: PDF in EnglishDB/T 59-2015 EARTHQUAKE INDUSTRIAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 91.120.25 P 15 Technical requirements of instruments in network for earthquake monitoring - Seismic intensity instrument ISSUED ON: JANUARY 28, 2015 IMPLEMENTED ON: MARCH 01, 2015 Issued by: China Earthquake Administration Table of Contents Foreword ... 3 Introduction ... 5 1 Scope ... 6 2 Normative references ... 6 3 Terms, definitions, symbols and abbreviations ... 7 4 Technical requirements ... 8 5 Test of technical indicators ... 12 Bibliography ... 20 Technical requirements of instruments in network for earthquake monitoring - Seismic intensity instrument 1 Scope This Standard specifies technical requirements and test methods for seismic intensity instrument in network. This Standard is applicable to design, production, use, maintenance and quality supervision of seismic intensity instrument. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB 4208-2008, Degrees of protection provided by enclosure (IP Code) GB/T 6587-2012, General specification for electronic measuring instruments GB/T 17626.5-2008, Electromagnetic compatibility - Testing and measurement techniques - Surge immunity test GB/T 17626.17-2005, Electromagnetic Compatibility - Testing and measurement techniques - Ripple on d.c. input power port immunity test GB/T 17626.29-2006, Electromagnetic compatibility (EMC) - Testing and measurement techniques - Voltage dips short interruptions and voltage variations on d.c. input power port immunity tests DB/T 21-2007, Technical requirements of instruments in network for earthquake monitoring. The description of common technical parameter and test method GJB 101A-1997, General specification for environmentally resistant quick release small circular electrical connectors This Standard uses the following symbols and abbreviations: E-W: East-west direction N-S: North-south direction U-D: Upright direction FIR: Finite Impulse Response IIR: Infinite Impulse Response LTA: Long-Time Average STA: Short-Time Average TCP: Transmission Control Protocol IP: Internet Protocol FTP: File Transfer Protocol POE: Power Over Ethernet NTP: Network Time Protocol UTC: Coordinated Universal Time 4 Technical requirements 4.1 Acquisition of ground motion signals The seismic intensity instrument shall have the ability to simultaneously acquire ground motion signals in three directions: E-W, N-S, and U-D. 4.2 Main technical indicators Main technical indicators of seismic intensity instrument shall meet the requirements of Table 1. Table 1 -- Main technical indicators of seismic intensity instrument No. Item Technical indicator 1 Acceleration measurement range -19.6m/s2~19.6m/s2 (E-W and N-S) -19.6m/s2~19.6m/s2 or -29.4m/s2~9.8m/s2 (U-D) 2 Acceleration measurement error < 5% (0.1Hz~20Hz) 3 Linearity error < 1% 4 Frequency band range Low frequency cut-off frequency: ≤0.01Hz (-3dB) 4.5 Records of observed-measured waveform data 4.5.1 The seismic intensity instrument shall have the function of recording waveform data of E-W, N-S, U-D three-directional seismic events to automatically generate event data files. 4.5.2 The event data files shall include waveform data between 30s before the event trigger time and the end of the event, as well as geographic coordinates of the observation point, site type, installation method, time code, sampling rate and other information. 4.5.3 The storage time for the event data files shall not be less than 3 months. 4.6 Transmission of observed-measured waveform data 4.6.1 When the seismic intensity instrument is at the event triggering, it shall be able to transmit E-W, N-S, U-D three-directional waveform data, including 30s data before the event to the remote server, until the event ends. 4.6.2 The seismic intensity instrument shall have continuous data transmission function to timely transmit E-W, N-S, U-D three-directional acquisition data. 4.6.3 When the seismic intensity instrument is transmitting event data or continuous data, the delay time of the output data shall not exceed 1s. 4.7 Event trigging information transmission When an event is triggered, the seismic intensity instrument shall use the predetermined server IP address to immediately send the event triggering information to the server, including triggering time, triggering parameters, observation point number, geographical coordinates of the observation point. 4.8 PGA, PGV, intensity value transmission For the measured instantaneous PGA and PGV values and their measurement time, it shall use the predetermined server IP address to immediately send them to the server. At the end of an event, it shall send final PGA value, PGV value, and instrumental seismic intensity value of the earthquake event. 4.9 Timing protocol 4.9.1 The seismic intensity instrument shall have the ability to synchronize with standard UTC time via satellite timing (compass system, GPS) or network time protocol (NTP). Use UTC time to mark the moment of sampling data. Use UTC time to represent time information that is output in other data. 4.9.2 The synchronization error between the seismic intensity instrument and UTC time shall not be greater than 0.1s. Standard acceleration sensor and data collector Extended uncertainty (k=2) ≤5% (0.1Hz~100Hz) 5.1.2 Test ambient temperature shall be in the range of 15°C~25°C. The relative humidity shall be less than 75%, without strong vibration interference. 5.2 Amplitude-frequency characteristics and acceleration measurement error 5.2.1 Test signal frequency and amplitude When the sampling rate of the seismic intensity instrument is 50Hz, the frequency of the test signal shall be selected from 1Hz, 5Hz, 10Hz, 15Hz, 19Hz, 21Hz, and 33Hz. When the sampling rate of the seismic intensity instrument is 100Hz, the frequency of the test signal shall be selected from 1Hz, 5Hz, 10Hz, 20Hz, 30Hz, 35Hz, 39Hz, and 65Hz. When the sampling rate of the seismic intensity instrument is 200Hz, the frequency of the test signal shall be selected from 1Hz, 5Hz, 10Hz, 20Hz, 30Hz, 40Hz, 60Hz, 78Hz, and 130Hz. The effective value of the test signal amplitude shall be selected as 5m/s2. If the displacement amplitude of the vibration table is not large enough, it may choose an appropriate acceleration test amplitude at the frequency of 1Hz according to the maximum displacement amplitude limit of the vibration table. 5.2.2 Vertical vibration table test The seismic intensity instrument to be tested shall be fixed on the vertical vibration table. According to the selected test signal frequency and amplitude, set the parameters of the vibration table in order and start the vibration table to operate. At the same time, set the seismic intensity instrument to record and collect data. Each test frequency point shall record the collected data of not less than 60s. 5.2.3 Horizontal vibration table test 5.2.3.1 The seismic intensity instrument shall respectively conduct the horizontal vibration table test in E-W and N-S directions. 5.2.3.2 When testing, the seismic intensity instrument to be tested shall be fixed on the horizontal vibration table. It shall make E-W (or N-S) direction of the seismic intensity instrument parallel to the vibration direction of the vibration table. According to the selected test signal frequency and amplitude, set the parameters of the vibration table in order and start the vibration table to operate. At the same time, set the seismic intensity instrument to record and collect data. Each test frequency point shall record the collected data of not less than 60s. 5.2.4 Data processing 5.5.1 Selection of test signal Use sweep signal to test. The sweep signal frequency range is not less than 5Hz~15Hz. The frequency change rate is 1Hz/s. The sweep signal amplitude shall be 5m/s2. 5.5.2 Test steps Conduct the test according to the following steps: a) Fix the seismic intensity instrument and the acceleration sensor on the vibration table at the same time. The analog output of the acceleration sensor is connected to data collector; b) The data collector adopts standard clock timing. The seismic intensity instrument adopts standard clock, NTP time server or satellite timing receiver; c) Set sampling rate of the data collector according to sampling rate of the seismic intensity instrument; d) After the seismic intensity instrument and the data collector are synchronized to the standard time, start the vibration table to output the frequency sweep test signal; e) Set the seismic intensity instrument to record and collect data. At the same time, record the data collected by the data collector. 5.5.3 Data processing and determination Conduct data processing according to the following steps: a) Data interception. Respectively according to the time information in the recorded data of the seismic intensity instrument and the data collector, intercept data for the same time period that contains the frequency sweep signal. The length of the intercepted data segment is not less than 10s; b) Calculate their cross-correlation; c) Calculate timing error. Read the number of sampling points where the maximum peak of cross-correlation is off-center. The product of the number of sampling points and the sampling period is the time deviation between the seismic intensity instrument and the data collector, which can be regarded as the timing error test result of the seismic intensity instrument; d) Determination. The test results shall meet the requirements of 4.9.2. a) Fix the seismic intensity instrument to be tested and the three-directional standard sensor in parallel on the .......Source: https://www.ChineseStandard.net/PDF.aspx/DBT59-2015 |