Trillium 120P Seismometer User Guide
Contents
1. EA Trillium 120P Seismometer User Guide 2005 2006 Nanometrics Inc All Rights Reserved Trillium 120P Seismometer User Guide The information in this document has been carefully reviewed and is believed to be reliable Nanometrics Inc reserves the right to make changes at any time without notice to improve the reliability and function of the product No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without the prior written permis sion of Nanometrics Inc Nanometrics Inc 250 Herzberg Road Kanata Ontario Canada K2K 2A1 Tel 613 592 6776 Fax 613 592 5929 Email info nanometrics ca www nanometrics ca Part number 15149R3 Release date 2006 04 27 Contents FIQUICS sis nar od a ete a nee Roi reri dod V MI p H vii Introduction a mt emad Dt Ama aa aa ECCO UE 1 FOALS DA UIN HQ E a ee E 3 Site Selection eee en eed a Teu reper EDO Soda oe had ages at a 3 AA cocer dela Re terree eue ere vip ea e MERI E ei eee 3 Goncrele selecti n zur s Muni KPA naka EE epe a Deiner 3 Mault wall decoupling 5 iu ure bx RR b annealed eR bp AA ER NANG 4 Thermal insulation nes md na conem soe sa He an 4 Gable design rn ze ee PAA AA A e Rua Mu cri cu te eru 4 Installation Seed mut de a Celene Dated ted hj aita rs Le E a inda dU See a B Unp2. To Support 1 613 592 5929 2 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Preparation This chapter provides general preinstallation guidelines for the Trillium 120P These are intended to help achieve the best possible performance but some guidelines may not be applicable for all types of site or study 2 1 Site selection There is no substitute for a geological survey when it comes to site selection so that the structures over which the sensor is to be installed are known Low porosity is important as water seepage through the rock can cause tilts which overwhelm the seismic signal at long periods Clay soils and to a lesser extent sand are especially bad in this sense A seismic sensor should be installed on bedrock whenever possible and as far away as possible from sources of cultural noise such as roads dwellings and tall structures 2 2 Pier construction It is recommended that piers be rectangular rather than round whenever possible Rigid foam thermal insulation boxes can be made to fit a rectangular pier more easily The pier should be 2 to 4 thick The surface area should be sized to accommodate the sensors and associated cabling as well as any foam insulation boxes which are to be used The surface of the pier should be as smooth and level as possible and clear of debris 2 2 1 Concrete selection The concrete used in a seismic pier should be as homogeneous as possible to avoid inducing tilts d
3. lt Product gt Trillium Firmware lt Product gt lt Version gt 3 30 lt Version gt lt Temperature gt 17 51 lt Temperature gt lt Mass gt U 2 227 V 0 143 W 2 656 lt Mass gt lt Adc gt U 1007 V 65 W 1200 lt Adc gt lt Modes gt Period Long Channel XYZ lt Modes gt lt SOH gt Version The version of the firmware that is currently running Temperature The temperature near the main electronics PCB which is located in a chamber near the top of the unit This is an approximate measure only The mass positions for each axis U V W These are reported in two forms Mass decimal numbers with a 4 2 range that roughly corresponds to the output voltage at the U_MP V_MP and W_MP signals lt ADC gt proportional integer numbers with a range of 1900 The lt ADC gt number is about 452 times the lt Mass gt decimal number The lt Mass gt or lt ADC gt numbers may be used to judge whether the masses are accurately centred If the sensor is in long period mode normal operation be sure the sensor has been powered on and undisturbed for at least 30 minutes before using lt Mass gt or lt ADC gt numbers If the sensor is in short period mode the mass position numbers will settle within 1 to 2 seconds Modes The sensor modes are reported including whether the sensor is in long period or short period mode and whether the seismic signals are output in XYZ or UVW mode ShortPer Set sensor
4. 0 3 V the sensor is sufficiently centred that it will report seismic signals properly However the closer the mass positions are to 0 V the more room there is to tolerate further ambient temperature changes For this condition centring the masses is recommended if it is convenient to do so If the mass positions are all within the range 0 3 V there is no need to recentre although it can be done if desired 3 6 1 Mass centring procedure This procedure requires a 2 0mm hex screwdriver with a long shaft and a 2 5mm hex screwdriver both are supplied in the Trillium maintenance kit 1 2 Install and level the Trillium 120P as precisely as possible Wait at least 4 hours for the temperature of the sensor case to come to equilibrium with the temperature of the vault before centring the masses Check the voltage readings on the mass position outputs for each of the three sen sor channels signals U MP V MP and W_MP referenced to AGND to deter mine whether mass centring needs to be done Table 3 1 Table 3 1 Mass position output voltage indicating need for mass centring Mass position output voltage Need to cenire the masses outside the range 3 5V yes within the range 3 5V but not within the range 2V strongly recommended within the range 2V but not within the range 0 3V recommended if it is convenient mass positions are all within the range 0 3V no although it can be done if desired 4 Set
5. a new installation it is good practice to physically recentre the booms This ensures the unit will then be able to tolerate up to 45 C range variation in ambient temperature without requiring recentring When using a Nanometrics digitizer such as a Taurus or Trident that is connected to a network you can read the mass position status remotely For the Taurus use options in the Sensor page either locally or on an external browser For the Trident use options on the Nanometrics UI Trident gt Operation gt Instrument page or use Nags View The mass position status is also reported digitally via the RS 232 serial interface see Sec tion 4 9 Connecting and configuring the serial port on page 22 10 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Chapter 3 Installation To determine whether mass centring needs to be done you can check the voltage read ings on the mass position outputs for each of the three sensor channels signals U_MP V_MP and W MP referenced to AGND If the values are outside the range 3 5 V the sensor may not be able to report seis mic signals properly For this condition mass centring must be done If the values are within the range 3 5 V but not within the range 2 V the sensor is sufficiently centred that it will report seismic signals properly However it is strongly recommended the masses be recentred If the values are within the range 2 V but not within the range
6. calibration in XYZ or UVW mode One voltage input for all channels Three separate control signals to enable U V or W channels Control inputs Isolated active high referenced to DGND Serial port RS 232 compatible For instrument control and retrieval of configuration information A 4 Power Supply voltage 9V to 36V DC isolated input Power consumption 650mW typical at 15V input Protection Reverse voltage protected Self resetting over current protection No fuse to replace A 5 Physical Diameter 21 0cm Height 20 9cm to 21 8cm depending on levelling foot extension Weight 7 2kg Handling Detachable lifting handle included Parasitic resonances None below 130Hz A 6 Environmental Operating temperature 20 C to 50 C Storage temperature 40 C to 70 C Pressure Enclosure optimized to be insensitive to atmospheric variations Humidity Oto 100 Shock 20g half sine 5ms without damage 6 axes No mass lock required for transport Weather resistance Rated to IP68 and NEMA 6P for outdoor use dust and immersion resistance 28 Trillium 120P Seismometer User Guide 15149R3 2006 04 27 Connector Pinout The Trillium 120P connector is a 19 pin male military circular type hermetic connec tor The pinout is given in Table B 1 Table B 1 Connector pinout Pin Name Fun
7. in Serial Transmit mode The sensor responds to whichever command serial port or control line last signalled a change 15149R3 2006 04 27 Trillium 120P Seismometer 25 User Guide Chapter 4 Operation Table 4 3 Serial port commands Continued Command Description Center Center all Do not use this command It is for Trillium models that have motorized masses or u v w automatic mass centring capabilities Future versions of the firmware for this model will not include this command CheckSum Print check Use the CheckSum command to check the firmware checksums of both sum values for both partitions and what they should be This is useful to ensure there is valid program A and B code in each partition for example before switching to the alternate firmware partition 4 10 Troubleshooting and maintenance The Trillium 120P mechanical and electronic elements have been designed to be robust and reliable to ensure there is no need to open units for on site maintenance The inter nal reverse voltage protection and over current protection automatically resets when the fault is removed so there are no fuses to replace In the unlikely event the sensor does not operate correctly please contact Nanometrics support see Chapter 1 Introduction 26 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Specifications This section lists the specifications of the Trillium 120P A 1 T
8. the levelling feet as little as possible to achieve a level sensor Keep at least one of the feet two if possible retracted fully into the sensor base 6 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Chapter 3 Installation 5 Align the sensor precisely to North South If you are using a scribed line on the pier align the line drawn on the pier with the vertical North South lines on the base Figure 3 2 Some care is required to avoid sighting at an angle and introducing a parallax error Pull the insulation back as required to see the alignment line on the pier If you are aligning to a North South staked line hold a straight edge in the North South guide on top of the sensor case Figure 3 3 on page 8 and align the straight edge to the staked line 6 After you have aligned the sensor to North South the sensor may need to be relev elled due to unevenness in the pier While the sensor will operate properly with the bubble anywhere inside the black ring on the level the bubble should be centred as precisely as possible to ensure the Z output is measuring true vertical motion 7 Check the alignment again after levelling Figure 3 2 Sensor alignment using the North South lines on the base 15149R3 Trillium 120P Seismometer 7 2006 04 27 User Guide Chapter 3 Installation Figure 3 3 Sensor alignment using a staked line and the North South guide lt Place the sensor under a line staked to Nor
9. to short period mode LongPer Set sensor to long period mode Use the ShortPer and LongPer commands to set the electronic mass centring response of the sensor to short period or to long period respectively Short period mode should be used when mechanically recentring the masses Ensure that you restore the sensor to its normal operating mode typically long period mode when mass centring is completed Long period mode is the normal mode for collecting seismic data and is essential to obtain the low frequency broadband performance Short period mode is useful to see the mass positions respond quickly signals U_MP V_MP W MP or the SOH lt Mass gt or lt ADC gt values when the sensor is being levelled In long period mode these numbers ramp very slowly and so care must be taken to not be misled by apparently centred values when in fact the sensor is not centred In short period mode these numbers respond within a second The sensor always powers up in long period mode Long period is the normal response for a 120 second lower corner frequency SetXYZ Set sensor to XYZ mode SetUVW Set sensor to UVW mode Use the Set XYZ and SetUVW commands to set the seismic output signals to the conventional XYZ horizontals and vertical mode or to the natural UVW mode in which the output of each axis is given directly XYZ mode is the default Note that this mode is also set by the UVW TX input line when the sensor is not
10. 0 45 gt 0 Q 45 G iiilHiH i ERN HI nn ES c a 90 135 Seismometer Calibration 180 Combined Response 10 10 10 10 10 10 Frequency Hz 4 6 Self noise Typical Trillium 120P self noise is plotted in Figure 4 3 Three curves are included for reference Peterson s new low noise model NLNM and new high noise model NHNM and McNamara and Buland s PDF Mode Low Noise Model MLNM The noise floor specification is valid when the masses are centred within 0 4 V The noise floor in the low frequency area will increase if the masses are further decentred The self noise at 100 seconds could rise to as high as 168dB if the masses are off centre by the maximum 4 5 V Therefore to obtain the best low noise performance it is best to ensure the masses are well centred 1 See also Peterson J 1993 Observations and Modeling of Seismic Background Noise Open file report 93 922 U S Geological Survey McNamara D E and R P Buland 1994 Ambient Noise Levels in the Continental United States Bull Seism Soc Am 94 1517 1527 Clinton J E and T H Heaton 2002 Potential Advantages of a Strong motion Velocity Meter over a Strong motion Accelerometer Seism Res Lett 73 332 342 15149R3 2006 04 27 Trillium 120P Seismometer 1 9 User Guide Chapter 4 Operation The noise floor shown is the typical level of instrument self noise assuming proper installation To achieve b
11. 3 User Guide 2006 04 27 Chapter 4 Operation Nanometrics Trillium User Menu Version 3 30 Program A kc ck ck KKK KK KKK KKK KK KKK KKK KKK KKK KK KKK KKK KEK KKK A Help Repeat this menu also turns on Serial TX Tx Enable the Serial Transmit Signal TxOff Disable the Serial Transmit Signal Upload Upload software to the alternate program Switch Switch to the alternate program Default Set the current program as default Reboot Reboot the instrument GetInfo Get factory configuration information ReadFC Read factory calibration parameters WriteUC Write user calibration parameters ReadUC Read the user calibration parameters Soh Report state of health ShortPer Set sensor to short period mode LongPer Set sensor to long period mode SetXYZ Set sensor to XYZ mode SetUVW Set sensor to UVW mode Center Center all masses or u v w CheckSum Print checksum value for both program A and B CK CK CK CK KC CC CK CK CK CCS Sk Sk SS Sk Sk Sk Sk Sk S Sk I S kk Sk kk TH TH kk kk kk kk Sk kk KKK A A A Please type a command and hit return Each of the serial port commands is described in Table 4 3 Table 4 3 Serial port commands Command Description Help Repeat this menu also turns on Serial TX Use the Help command to view the list of commands The first line identifies the firmware version in use and whether it is Program A or Program B The Help command also turns on the TX
12. Alignment FS ure dp oe cb ethane a ee ee qe 33 Figures 1 1 3 1 3 2 3 3 3 4 3 5 4 1 4 2 4 3 D 1 D 2 Trillium 120P seismometer 0000 nennen nennen nennen 1 Fibreglass batt insulation under a seismometer Trillium 240 model shown 6 Sensor alignment using the North South lines on the base 7 Sensor alignment using a staked line and the North South guide 8 Wrapping a sensor with fibreglass batt insulation Trillium 240 model shown 9 Mass position adjustment access seal screws 0 12 Sensor axis orientations 0 0 0 s n 17 Nominal frequency response 1 2 0 cette ee 19 Trillium 120P self noise 000 en 20 Trillium 120P performance eae 21 Alignment features top vView ec een 34 Alignment features bottom view 1 2 2 0 ee teens 35 Figures vi Tables 3 1 4 1 4 2 4 3 B 1 C 1 Mass position output voltage indicating need for mass centring 11 Axis orientation and polarity of XYZ outputs ree 16 BG oannes te Dette sco e dates ir RT n 18 Serial port commands 0000 cette 23 Connector pinout 00 0 29 Generic sensor cable wiring for CBLI3942R2 2 000 eee 32 vii Tables viii Chapter Introduction Trillium Model 120P is a three component broadband low noise seismometer suitable for portable a
13. DE 34 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Appendix D Alignment Features Figure D 2 Alignment features bottom view 3 HOLES FOR M10 x 1 0 METRIC BOLT 20mm DEEP t 9 173 120 Q 210 120 210 43 105 43 Y SENSOR CONNECTOR All dimensions are in millimetres unless otherwise noted 15149R3 Trillium 120P Seismometer 35 2006 04 27 User Guide Appendix D Alignment Features 36 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27
14. North South axis a North South guide on the top of the case and 5 16 diameter holes for alignment rods oriented to East West To level the Trillium 120P use the three adjustable height feet with lock nuts and the levelling bubble on the cover For the most precise alignment possible two 5 16 diameter holes aligned to East West are provided in the sensor base into which 5 16 alignment rods not supplied can be fitted Using the North South alignment marks to align visually with an accurately scribed North South mark on the pier will be precise enough for most installations The sensor can also be precisely oriented to a stretched line such as a length of fishing line 15149R3 2006 04 27 Trillium 120P Seismometer 5 User Guide Chapter 3 Installation by using a straight edge held against the guide on the top of the sensor See Appendix D for top and bottom views of the Trillium 120P showing the relative orientation of the North South and East West alignment features 1 Draw a line on the pier parallel to North South Alternatively if you are using the North South guide you may stake a line for example fishing line parallel to North South directly over the location where you want to install the Trillium 120P The North South line or East West line if you are using the alignment rods must be aligned to true North East If you are using a magnetic compass account for the local magnetic declination when drawing the lin
15. The fibreglass pipe should be snug enough so that there are no air gaps between the insulation and the sides of the sensor but loose enough that it can be slid up off the sensor or replaced by sliding down over the sensor easily without using force gt Do not cover the top to ensure heat can be dissipated properly through the top of the sensor Figure 3 4 Wrapping a sensor with fibreglass batt insulation Trillium 240 model shown 3 5 2 Install the rigid foam insulation box For the outer layer of insulation we recommend a five sided box constructed using rigid polystyrene or polyisocyanuratic foam insulation Alternatively rigid foam insu lation with foil on one side can be used There are two advantages to the foil coated foam it has a higher insulation resistance and the joints can be made using packing tape which is quicker and less messy than glue 15149R3 2006 04 27 Trillium 120P Seismometer 9 User Guide Chapter 3 Installation Recommendations for constructing the thermal insulation box Use insulation that is at least 2 5cm thick Depending on the temperature stabil ity of the site additional or thicker boxes may be used gt Make the insulation box large enough that it is not touching the sensor cables or fibreglass insulation gt Cut a groove in the bottom of one edge of the box to allow the sensor cable to exit at the appropriate point gt Seal the box joints properly gt For rigid foa
16. acking tlie Sensor v ver EE Exc RU ax aa C EIE E e RA 5 Optional thermal insulation 2 2 0 0 00 000 nh 5 Orientation and levelling IRI Ih 5 Installing the sensor cable 222m sonen IIIA 8 Installing the thermal insulation llli 9 Optional Install the fibreglass batt insulation 0 0 eee eee eee 9 Install the rigid foam insulation box eee 9 Mass centfings ue pa pea Yet ees Oe ta Lag eee ees ne ae eee ele wee 10 Mass centring procedure eee ae 11 Installation checklist ete eee 13 eiu wir sa ra SS 15 External connector eh me 15 Sensor PO WEE asa ee a ee Oe nada be 15 Control signal ut ANG ad a 16 Output sigrials 2 mte a erde iene red ae be eee Ka 16 Frequency response 1 2 ee tee nn 18 SEIFNDISE so ee a a e ne ie ere ee 19 Galibration 2i Hh eee lb ld e e oc e il beeen eee 21 State of Health 0 0 0 AG 22 Connecting and configuring the serial port 0000 22 Troubleshooting and maintenance 0 0 nennen 26 Specifications mM sr DD rre 27 Technology er rer Ta er ee fet sese ir oe ehe enden 27 Performances alad er 27 Interface sel od el ed oe ia Ro e o oad ie 28 POWER D 28 Physical ee eee dre ee et eles 28 Contents Environmental aaa dara haa ba aaa ara ap ela pda ni fed bee il 28 Connector PINCUS eka a la ee oon es eae sae eer ee hee Ne 29 Generic Sensor Cable kaaa sawa temas hme san iut eos ob noe d resus 31
17. ction Type L Z W vertical W axis output M Z W N Y V north south V axis output 40V peak to peak differential A Y N P X U east west U axis output B X U En A i 9 2kQ input impedance T AL SI CAL_SIG calibration signal input ER RT K U_CALEN J V_CALEN calibration enable inputs ven low open or OV U W_CALEN E U_MP F V_MP mass position outputs 4 5V single ended S W MP V AGND analog ground N A H PWR power input 9V to 36V DC isolated G PWR power return input enable UVW instead of XYZ as UVW input active high 5 D UVW TX outputs to 15V low open or OV output serial RS 232 transmit as TX output 5V input enable short period as SP enable active high 5 C SP RX response for mass centring to 15V low 2 open or OV input serial RS 232 receive as RX input 5 V OV to 215V R DGND digital ground N A shell CHASSIS for shielding and safety N A 15149R3 2006 04 27 Trillium 120P Seismometer User Guide 29 Appendix B Connector Pinout 30 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Generic Sensor Cable A generic sensor cable may have been shipped with your sensor Table C 1 on page 32 is the wiring key for the standard cable Nanometrics part number CBL13942R2 This table can be used as a reference when wiring the generic sensor cable end to a digitizer connector 15149R3 2006 04 27 Trillium 120P Seismometer 31 User Guide Appendix C Gen
18. dix B for the connector pinout 4 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Installation Once the vault has been prepared use the procedures described in this chapter to install the Trillium 120P Section 3 7 on page 13 provides a generic installation checklist 3 1 Unpacking the sensor The Trillium 120P is shipped in a very sturdy triple wall coated cardboard box with custom cut cushioning foam To minimize the possibility of damaging the sensor do not remove it from the box until it is ready to be placed directly on the pier gt Save the box and foam in case the sensor needs to be shipped again A removable lifting handle has been provided with your seismometer You can use the lifting handle to facilitate installation of the sensor in vaults which are accessible only from the top Do not use the lifting handle to carry the Trillium 120P To use the lifting handle screw it securely into the threaded hole at the center of the sensor cover Remove the lifting handle once the sensor is installed 3 2 Optional thermal insulation To maximize long period performance we recommend wrapping fibreglass batt insu lation around and under the Trillium 120P and then installing a rigid foam insulation box For some installations one or the other will be sufficient or may not be required 3 3 Orientation and levelling Three alignment features are integral to the Trillium 120P vertically scribed marks on the
19. e Caution Fibreglass insulation may irritate skin Use gloves when handling fibre glass batt insulation 2 Optional Prepare the bottom layer of thermal insulation Figure 3 1 This is to eliminate air currents between the pier and the underside of the Trillium 120P a Place a layer approximately 1 or 3cm of fibreglass batt insulation flat on the pier The insulation should be thick enough to take up the air gap but should not be tightly compressed once the sensor is installed b Make holes in the insulation spaced to accommodate the Trillium 120P level ling feet Figure 3 1 Fibreglass batt insulation under a seismometer Trillium 240 model shown 3 Take the Trillium 120P out of its box and place it gently down on the pier aligned approximately to North South The North marker line on the Trillium 120P base is the one just to the left of the sensor connector and label Figure 3 2 gt Ensure that no insulation is caught under the levelling feet of the sensor All three levelling feet must rest directly on the surface of the pier 4 Unlock the feet as required to level the sensor and then lock them again by thread ing the lock nut up until it engages firmly with the base Note that the locknut has a mechanical stop that prevents it from loosening more than a third of a turn It may be necessary to hold the body of the levelling foot still while locking the nut to avoid disturbing the levelness of the sensor gt Extend
20. e mass position output will increase in the positive direction when the screw is turned counter clockwise If the mass position output voltage does not change when you turn the screw check the following three conditions gt Ensure you are adjusting the channel corresponding to the mass position output being monitored gt Ensure the sensor is in short period mode otherwise the mass position out puts will change far too slowly to be useful in centring the masses gt If the mass position output is greater than 43 5 V ensure the sensor is pre cisely levelled and be sure to turn the screw clockwise if the voltage is pos itive and counter clockwise if the voltage is negative Using the 2 5 mm hex wrench replace the seal screw Tighten the seal screw to hand tight 9 inch pounds 6 Setthe sensor back to long period response mode Figure 3 5 Mass position adjustment access seal screws 1 2 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Chapter 3 Installation 3 7 Installation checklist This checklist can be used as an aid when installing the Trillium 120P LL Pier is clear of debris U Sensor is level U sensor is aligned to North South or East West U Sensor feet are locked U Sensor serial number is noted U cable is connected to the sensor and the digitizer U Cable is strain relieved to the pier O Cable is not touching the sensor case L Masses are centred after temperature equalization at lea
21. echnology Topology Symmetric triaxial Feedback Coil magnet force feedback with capacitive transducer Mass centring Operates over full temperature range without manual recentring Manual centring control included Levelling Integrated bubble level adjustable locking levelling feet Alignment Vertical scribe marks for North South North South guide on top of the case for straight edge line or laser level Precision holes for 5 16 alignment rods for East West A 2 Performance Self noise See Figure 4 3 on page 20 Sensitivity 1201 V s m 0 5 Bandwidth 3dB points are 120s and 175Hz Transfer function Lower corner poles within 0 5 of nominal provided High frequency poles and zeros within 5 of nominal provided Clip level 15mm s peak to peak differential up to 1 5Hz see also Figure 4 4 on page 21 Lower corner damping relative to critical 0 707 Output impedance 21509 1 Temperature 45 C without recentring Tilt Operational tilt range 1 5 Dynamic tilt Maximum tilt without recentring 0 2 15149R3 2006 04 27 Trillium 120P Seismometer 27 User Guide Appendix A Specifications A 3 Interface Connector 19 pin MIL C 26482 mounted on base Velocity output Selectable XYZ east north vertical or UVW mode 40V peak to peak differential Mass position output Three independent 4 5V outputs for UVW Calibration input Remote
22. eric Sensor Cable Table C 1 Generic sensor cable wiring for CBL13942R2 From To Wire Run Conn Pin Name Conn Pin Name Colour P1 L Z W P2 CH1 RED 1 P1 M Z W P2 CH1 BLK 1 P1 P2 CH1GND DRAIN 1 P1 Y V P2 CH2 WHT 2 P1 Y N P2 CH2 BLK 2 P1 P2 CH2GND DRAIN 2 P1 P X U P2 CH3 GRN 3 P1 B X U P2 CH3 BLK 3 P1 P2 CH3GND DRAIN 3 P1 T CAL SIG P2 CAL1 BLU 4 P1 U W_CALEN P2 CAL1 CTRL4 BLK 4 P1 SHELL P2 SHELL DRAIN 4 P1 J V_CALEN P2 CAL2 CTRL5 YEL 5 P1 K U_CALEN P2 CAL3 CTRL6 BLK 5 P1 SHELL P2 SHELL DRAIN 5 P1 W MP P2 EXT SOH1 BRN 6 P1 F V MP P2 EXT SOH2 BLK 6 P1 SHELL P2 SHELL DRAIN 6 P1 U MP P2 EXT SOH3 ORG 7 P1 V AGND P1 CH1GND BLK 7 P1 SHELL P2 SHELL DRAIN 7 P1 H PWR P2 SEN 12V RED 8 P1 G PWR P2 SENRTN WHT 8 P1 SHELL P2 SHELL DRAIN 8 P1 D UVW TX P2 CTRL1 RED 9 P1 SP RX P2 CTRL2 GRN 9 P1 R DGND P2 DGND DRAIN 9 P1 SHELL P2 SHELL BRAID 32 Trillium 120P Seismometer User Guide 15149R3 2006 04 27 Alignment Features See Figure D 1 and Figure D 2 for top and bottom views of the Trillium 120P showing the relative orientation of the North South and East West alignment features 15149R3 Trillium 120P Seismometer 33 2006 04 27 User Guide Appendix D Alignment Features Figure D 1 Alignment features top view EAST WEST ALIGNMENT ROD HOLES BUBBLE LEVEL NORTH SOUTH GUI
23. es to attenuate the ambient temperature variations to isolate the sensor from drafts and to localize and minimize air convection currents We have repeatedly seen in our testing the critical importance of thermal insulation to long period noise performance with a variety of sensors and sites We recommend wrapping a layer of fibreglass batt insulation around the Trillium 120P and then installing a rigid foam insulation box See also Section 3 5 Installing the thermal insulation on page 9 2 4 Cable design Cable design guidelines gt Sensor cables should be designed for good EMI shielding This is most easily accomplished using double shielded twisted pair cable The twisted pairs provide magnetic shielding an inner shield grounded at the digitizer provides good electric field shielding and a continuous outer shield provides good high frequency RF shielding gt The outer shield should be earthed at the digitizer for safety gt The digital ground DGND must be used for the return currents of the control sig nals U CALEN V_CALEN W_CALEN UVW TX and SP RX gt The analog ground AGND must be used for the return currents of the analog sig nals CAL SIG U_MP V_MP and W MP gt Note that AGND is connected to chassis ground CHGND inside the Trillium 120P so if these signals are already connected at the digitizer AGND should not be connected through the cable or else a ground loop will be created See Appen
24. est performance for any sensor meticulous attention to detail must be paid to choice of site vault design and sensor installation The New Manual of Seismological Observatory Practice TASPEI 2002 has a good discussion of the rel evant best practices see the publisher s site http www gfz potsdam de pb2 pb21 for information on the NMSOP Figure 4 3 Trillium 120P self noise PSD dB wrt 1 m s Hz 100 NLNM a sat MILAM Trillium 120P 120 En Q2 o EN gt o 160 Frequency Hz To determine the dynamic range at frequencies of interest for your application com pare the noise floor to the sensor clip level using Figure 4 4 In this figure for compar ison of noise floors to clip levels we convert power spectral densities using octave bandwidths and an RMS to peak conversion factor of 1 253 20 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Chapter 4 Operation Figure 4 4 Trillium 120P performance 20 M1 5 at 10 km at M3 5 at 10 km M5 5 at 10 km M1 5 at 100 km 1 M3 5 at 100 km 60 M5 5 at 100 km M7 at 100 km M6at 3000 km M8at 3000 km 80 Trillium 120 Self Noise Trillium 120 Clip Level Dig Noise Max Gain Dig Noise Min Gain Dig Clip Max Gain 100 Dig Clip Min Gain 140 160 Peak Velocity in Octave Bandwidth dB wrt 1 nf s 180 200 220 CA 1 DEI AA AN 2 ESI AAS APIS 10 10 10 107 10 10 Frequency Hz 4 7 Cal
25. h can be the same version or different versions one loaded in partition A the other in partition B The sensor will run the firmware from the default partition on power up Use the switch command to switch immediately to running the firmware in the other partition It does not change which partition is the default so that when the sensor is power cycled it will start up in the original default partition For example if the default partition is B and the Switch command is executed then partition A firmware is run immediately When the sensor is powered off and then on again it then switches back to running Partition B firmware gt Use the CheckSum command to ensure there is valid code in both parti tions before switching Default Set the cur rent program as default Use the Default command to set the running firmware partition to be the default partition loaded at power up For example if the sensor is running partition A by default on power up to change to running partition B instead the procedure is 1 Execute the SOH command to verify that partition A is running 2 Use the Checksum command to verify that there is valid code in both par titions 3 Execute the Switch command to change to running partition B and the SOH command to verify that the new firmware is running 4 Execute the Default command to set partition B to be the default on power up Reboot Reboot the instrument Use the Reboot command to
26. ibration Calibration inputs are provided to allow for relative calibration of the sensor across fre quency and over time Since the Trillium 120P is a symmetric triaxial sensor calibration must be performed on the individual sensor axes UVW rather than the horizontal and vertical outputs XYZ Individual axis outputs can be digitized by placing the sensor in UVW mode see Section 4 4 15149R3 2006 04 27 Trillium 120P Seismometer 21 User Guide Chapter 4 Operation Each axis has a separate calibration enable signal U_CALEN V_CALEN W_CALEN All axes use a common calibration input signal CAL_SIG which has a nominal sensitivity of 0 010m s V 4 8 State of Health Mass position output signals U MP V MP and W MP are provided to monitor the effect of tilt and temperature on the spring which sets the rest position of the boom As with the calibration signals they represent the state of the individual sensor axes UVW rather than the horizontal and vertical outputs XYZ The mass positions are zeroed at the factory at room temperature with the Trillium 120P perfectly level Ifthe mass positions are all within the range 0 3V then there is no need for recentring Otherwise follow the procedure in Section 3 6 1 Mass centring procedure on page 11 4 9 Connecting and configuring the serial port 1 Connect an appropriate RS 232 communications device such as a PC serial port to the sensor by connecting its TX
27. ion coil During calibration the measured response is the product of the calibration sys tem s lowpass response a single pole at 158 rad s and the sensor s own response Therefore the seismometer response to ground motion is obtained by dividing the combined response obtained during calibration by the calibration input nominal transfer function These three transfer functions are shown in Figure 4 2 The nominal poles p zeroes z normalization factor k and normalization fre quency fg and passband sensitivity S sensor ofthe Trillium 120P are listed in Table 4 2 These parameters define the transfer function according to this equation e 2 F s nar ke ES EQ 3 6 n Where the normalization factor is defined as follows k ee a EQ 4 IJE 2 2 fo tzn AAA 0 2 7 n Table 4 2 Poles and zeroes Parameter Nominal values Units 0 Z Zeroes 0 rad s n 106 158 0 03859 0 03649i 190 Pn Poles 158 1933 rad s 639 1418i k Normalization factor 1 695 x 10 Sensor Passband sensitivity at 1 Hz 1201 0 V s m To Normalization frequency 1 Hz The transfer function is approximately flat from 120s to 50Hz and rolls off at 40dB decade below the lower corner frequency as shown in Figure 4 2 1 8 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Chapter 4 Operation Figure 4 2 Nominal frequency response Magnitude dB 9
28. m without a foil coating glue the joints using polystyrene adhesive or polyurethane resin taking care to leave no gaps gt For rigid foam with a foil coating you can tape the joints with packing tape taking care to leave no gaps gt Ensure there is a good seal between the bottom edge of the box and the pier Adhe sive 0 5 1 25cm thick weatherstripping can be used to ensure a good seal gt Ensure the thermal insulation box is held firmly in place by setting a weight on top of the box A brick works well for this purpose 3 6 Mass centring The Trillium 120P masses are centred at the factory at 20 C If the sensor is level it will operate over the range 45 C without recentring If the sensor is not levelled accu rately then the operational temperature range will be reduced The Trillium 120P can be mass centred if the sensor is within 1 5 of level although it is good practice to ensure the sensor is levelled as precisely as possible before centring the masses Once the Trillium 120P has been precisely mass centred that is the mass position voltage is within the range 0 3 V the sensor can tolerate a shift of up to 0 2 without mass recentring being required Different operating ranges can be achieved by recentring the masses at different tem peratures For example to achieve operation from 20 C to 50 C the masses should be centred at a temperature within the range 5 to 25 C After temperature has stabilized in
29. n used as the RS 232 serial TX output signal See Section 4 9 Connecting and configuring the serial port on page 22 To understand the difference between the UVW and XYZ outputs refer to Figure 4 1 The sensor axes have been designed so that they are identical and so that the directions in which they sense motion are orthogonal The U axis was chosen to be aligned with the East West axis when projected into the horizontal plane 1 6 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Chapter 4 Operation Figure 4 1 Sensor axis orientations This arrangement results in the following transformation equations 2042 jx me rt 43 2r RM Ww 1 28 2 Z x i 2 1 1 u Eus a EQ 2 y 6 0 3 3 v Ww 42 42 42 The first equation is implemented mechanically in the orientation of the Trillium 120P individual sensor axes The second equation is implemented electronically when the Trillium 120P is in XYZ mode N Alternatively seismic data may be digitized with the Trillium 120P in UVW mode and the transformation to horizontal and vertical signals implemented optionally when the data are processed This allows for studies and calibrations where both UVW and XYZ data are required Trillium 120P Seismometer 1 7 15149R3 User Guide 2006 04 27 Chapter 4 Operation 4 5 Frequency response The frequency response of the Trillium 120P can be measured using the calibrat
30. nd fixed applications It operates over a wide temperature range without manual recentring and has low power consumption Its extended low frequency range low noise and wide dynamic range make it ideal for teleseismic studies as well as for regional and local events At only 7 2kg and 21cm in diameter the Trillium 120P is compact and portable Figure 1 1 Trillium 120P seismometer Trillium seismometers have a symmetric triaxial arrangement of the sensing elements The use of three identical axis elements ensures the same frequency response for ver tical and horizontal outputs is less susceptible to rapid changes in temperature and guarantees true orthogonality of the three outputs Data output of XYZ or UVW can be selected remotely allowing calibration of the ele ments independently of the electronics UVW data may also be used instead of XYZ for seismic signal recording if desired Please read the appropriate sections of this manual before transporting storing install ing or operating the Trillium 120P If you need technical support please submit your 15149R3 2006 04 27 Trillium 120P Seismometer 1 User Guide Chapter 1 Introduction request by email or fax Include a full explanation of the problem and supporting data to help us direct your request to the most knowledgeable person for reply Before returning a unit for repair contact Nanometrics Support to obtain an RMA number Email support nanometrics ca FAX
31. nputs can tolerate at least 15 V except for UVW TX which can tolerate voltages from 7 V to 15 V 4 4 Output signals The sensitivity specified in Table 4 2 on page 18 assumes an infinite input impedance at the digitizer For digitizers with low input impedance it will become necessary to account for the fact that source impedance of the differential outputs is 300 2 1 150Q each output A control signal switches the Trillium 120P output signal to either UVW output or XYZ output The natural sensor output is UVW in this mode the outputs represent the actual motion of the masses of the three sensor components The conventional sensor output is XYZ in this mode the outputs represent horizontal and vertical motion See Table 4 1 for the polarities of the XYZ outputs and their correspondence to the directions of the compass Table 4 1 Axis orientation and polarity of XYZ outputs Axis Orientation Positive voltage represents X east west case motion to east Y north south case motion to north Z vertical case motion upwards gt To select the sensor outputs gt To select the UVW outputs pull the UVW TX pin high gt To select the XYZ outputs either leave the UVW TX pin floating or set it to OV The sensor responds to changes on this control line within 4 seconds Note that this input control signal is disabled when the sensor is transmitting on the serial port since this pin is the
32. pin to the SP RX signal pin C and its RX pin to the UVW TX signal pin D Be sure to take appropriate precautions for signal shielding and grounding to avoid introducing unwanted noise into the sensor or onto adjacent signal wires in the cable or the seismic signal from the sensor may become noisy 2 Set the serial port on the communicating device to use this configuration e Speed 9600 baud Data Bits 8 Parity None Stop bits 1 Flow Control Xon Xoff 3 If you are using a terminal emulator program enable these settings Echo typed characters locally The Trillium 120P serial port does not echo received characters on its transmit port e Send line ends with line feeds or equivalent The serial port expects all com mands to be terminated with the carriage return character ASCII OxOD 4 Once the sensor is powered up and an appropriate serial device connected as above send the characters Tx lt CR gt the lt CR gt denotes the carriage return char acter Note that the serial commands are not case sensitive Tx TX and tx are equivalent After a delay of 3 seconds the sensor will enable the UVW TX output and transmit Serial Transmit Enabled lt LF gt lt CR gt 5 To view help on the commands send the help command Help lt CR gt to get the sensor to transmit a help page displaying the various commands and syntax This is what would be displayed 22 Trillium 120P Seismometer 15149R
33. restart the firmware GetInfo Get factory configuration informa tion ReadFC Read factory calibration parameters Use the commands Get Info and ReadFC to read factory information stored in the Trillium 120P Factory configuration information includes model version and serial numbers and other factory information for the unit axes and various circuit boards in the sensor This information is primarily used by Nanometrics Technical support Factory calibration parameters may include information regarding measured sensitivity transfer function and the like WriteUC Write user calibration parameters Use the command Writeuc to upload calibration information from a text file in Turtle format You can use ReadFC to view the factory calibration information for an example of the syntax For information on Turtle see http www ilrt bris ac uk discovery 2004 01 turtle For information on RDF in general see http www w3 org RDF ReadUC Read the user calibration parameters Use the ReadUC command to display calibration information stored using the Writeuc command Trillium 120P Seismometer User Guide 24 15149R3 2006 04 27 Chapter 4 Operation Table 4 3 Serial port commands Continued Command Description Soh Report state of health Use the SOH command to view state of health information as listed below lt SOH gt lt Manufacture gt Nanometrics Inc lt Manufacture gt
34. signal if it has not already been turned on after a delay of 3 seconds It is the only command besides Tx that will enable the sensor s serial transmit signal Tx Enable the Serial Transmit Signal The Tx command turns on the sensor s serial transmit signal signal UVW TX pin D after a delay of 3 seconds and sends the message Serial Transmit Enabled lt LF gt lt CR gt The serial transmit port stays enabled until turned off by the Txo command or by cycling the power to the sensor In this mode the UVW TX pin must not be used as an input pin for UVW mode TxOff Disable the Serial Transmit Signal The TxOff command turns off the sensor s serial transmit signal signal UVW TX pin D and then waits 3 seconds After the 3 second delay this pin will be interpreted as the UVW mode input pin Upload Upload soft ware to the alternat program Caution Please DO NOT use the Upload command unless specifically directed by Nanometrics Technical Sup port as it erases the firmware in the alternate parti tion The Upload command uploads a new version of firmware to the firmware partition A or B that is not currently running 15149R3 2006 04 27 Trillium 120P Seismometer 23 User Guide Chapter 4 Operation Table 4 3 Serial port commands Continued Command Description Switch Switch to the alternate program There are two instances of firmware loaded in the Trillium 120P whic
35. st 4 hours post installation L Thermal insulating box and fibreglass insulation are in place L Thermal insulating box is not touching the sensor cables or fibreglass insulation L Thermal insulating box is weighted down 15149R3 2006 04 27 Trillium 120P Seismometer 1 3 User Guide Chapter 3 Installation 1 4 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Operation This chapter provides operating parameters and instructions for the Trillium 120P 4 1 External connector The Trillium 120P connector is a 19 pin male military circular type hermetic connec tor The pinout is given in Appendix B 4 2 Sensor power The Trillium 120P can be powered using a DC source that can sustain 9 V to 36 V at the sensor connector Voltage drops over the cable must be accounted for and so the sup ply voltage at the source may need to be higher In normal operation the sensor is level and well centred there is a low seismic signal the sensor has settled for at least 30 minutes and serial transmit is disabled the power consumption is typically 650mW On startup the peak power surge may be up to 4 5 W briefly Power consumption above normal quiescent after the initial power on in rush is roughly proportional to the output signal If the sensor is not centred or has not yet settled the output signals will be at the maximum and power consumption may be as high as 3 W For a settled centred and level sensor a seismic signal
36. th South Hold a straight edge in the North South guide flush to the inside edge and align to the staked line 3 4 Installing the sensor cable 1 Connect the sensor cable The cable should be strain relieved to the pier at some point close to the sensor Strain relief can be accomplished with tie wraps and tie wrap anchors or with a heavy object 8 Trillium 120P Seismometer 15149R3 User Guide 2006 04 27 Chapter 3 Installation 2 Ensure that the digitizer case is solidly earthed and that the outer shield of the cable and the sensor case are thereby earthed 3 5 Installing the thermal insulation 3 5 1 Optional Install the fibreglass batt insulation A Caution Fibreglass insulation may irritate skin Use gloves when handling fibre glass batt insulation The Trillium 120P should be wrapped lightly on the sides and bottom but not the top with fibreglass batt style insulation usually pink or yellow in colour This eliminates residual convection air currents around the sensor which can disturb long period per formance The insulation works best when it is not tightly compressed and when it is snugly but not tightly fitted around the sensor see Figure 3 4 gt Wrap a layer of approximately 2 Scm about 12 30cm wide by 3 1m long snugly around the Trillium 120P forming a vertical pipe The fibreglass will adhere to itself at the overlap so no adhesive or tape is needed to keep it in place
37. that approaches the sensor s maximum clip level may draw as much as 2 W peak the average power consumption would be much lower For long cables be sure to account for the resistive voltage drop due to the cable itself For example 50m of 24 AWG wire has a resistance of 4 202 in each direc tion Therefore the voltage drop due to the possible 500mA startup in rush at 9V would be 4 2 V and the power supply must be able to briefly supply 13 2 V for this length of cable The supply should also be able to sustain a 2W peak output at a voltage that guarantees the sensor receives 9 V For the 50m cable example the peak current would be 220mA at 9 V and the voltage drop would be 1 9 V so the supply must be able to provide 220mA at 10 9 V to reliably power the sensor for maximum seismic signals when using a 50m cable 15149R3 Trillium 120P Seismometer 1 5 2006 04 27 User Guide Chapter 4 Operation 4 3 Control signals Trillium 120P has 5 digital control inputs SP RX UVW TX U CALEN V_CALEN and W_CALEN All of these inputs are optically isolated from both the input voltage and the output and calibration input signals Therefore signals applied to these pins must be referenced to DGND rather than PWR or AGND All of these inputs are active high Specifically any voltage greater than 3 5 V at a cur rent greater than 0 1 mA enables the relevant functionality while any voltage less than 1V or a high impedance disables it All i
38. the sensor in short period response mode using any of these methods gt Pull the SP RX control signal pin C high 5 V to 15 V referenced to DGND pin R The SP RX pin must remain high for the sensor to be in short period response mode Use the interface for the connected Taurus Advanced Configuration gt Sensor Details page or Trident Configuration page Sensor Control settings gt Use the serial port to issue a Short Per command see also Section 4 9 Con necting and configuring the serial port on page 22 15149R3 2006 04 27 Trillium 120P Seismometer 1 1 User Guide Chapter 3 Installation 5 For each channel with a mass position voltage output greater than 0 3 V do the following a b c d f Locate the access seal screw corresponding to the channel of interest using Fig ure 3 5 as a guide Using the 2 5 mm hex screwdriver remove the appropriate seal screw Inspect the O ring for damage for example cuts or pitting and get a replacement seal screw from the maintenance kit if the original seal screw appears to be dam aged Place the seal screw where it will remain clean during the procedure Insert the 2 0 mm hex screwdriver straight down the hole until it engages with the mass position adjustment screw head Adjust the screw by small increments while monitoring the mass position out put until it is less than 0 3 V The adjustment sensitivity is approximately 1turn 1 volt Th
39. ue to differing thermal coefficients of expansion Therefore no aggre gate should be used and the concrete should be free of air bubbles Since strength is not a concern in a seismic pier no steel reinforcing is needed The recommended mixture is 50 Portland cement and 50 sieved sand see Uhrham mer et al 1997 http www orfeus eu org wg wg2 guidelines guidelines htm After the concrete is poured it should be shaken to allow trapped bubbles to escape The con crete will have sufficiently hardened to set up the sensor after 24 hours However the 15149R3 2006 04 27 Trillium 120P Seismometer 3 User Guide Chapter 2 Preparation pier may still generate spurious signals as the concrete cures which can take two to four weeks 2 2 2 Vault wall decoupling When setting up the forms for the concrete be sure to include a gap between the edge of the concrete and the walls of the vault This decoupling of the pier from the vault wall is important because otherwise wind or other non seismic forces acting on the walls can be transferred to the pier These forces may cause the pier to tilt or twist and obscure the desired seismic signal These signals are mostly long period so vault wall decoupling is critical for quiet site long period studies 2 3 Thermal insulation All broadband sensors are sensitive to temperature variations Even at a very tempera ture stable site they must have some form of thermal insulation Insulation serv
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