Trillium 240 Seismometer User Guide
Contents
1. Pin Name Function Type L Z W vertical W axis output M Z IW N Y V north south V axis output 40V peak to peak differential A Y V P X U east west U axis output B X U y y 9 2kQ input impedance T CAL_SIG calibration signal input 2 0 010 m s V nominal K U_CALEN J V_CALEN calibration enable inputs active high EEN low open or 0V 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 initiate mass centring as MC input active high 5 to C MC RX input serial RS 232 receive 15V low open or OV as RX input 5V OV to 15V R DGND digital ground N A shell CHASSIS for shielding and safety N A Trillium 240 Seismometer User Guide 27 Appendix B Connector Pinout 2 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09 Generic Sensor Cable A generic sensor cable may have been shipped with your sensor Table C 1 on page 30 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 15672R3 Trillium 240 Seismometer 29 2005 12 09 User Guide Appendix C Ge2. EA Trillium 240 Seismometer User Guide 2005 Nanometrics Inc All Rights Reserved Trillium 240 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 Onanometrics ca www nanometrics ca Part number 15672R3 Release date 2005 12 09 Contents FIQUIOS sus ori a tias ed ame ta aa raras pads iii TADIOS siga atra re eo Sues ae ar ai gad ah O papis deseas v 5 tato et E a a e E SS E 1 Preparation ad A re Na ak Op U aan E RAAT En 3 SHO SC ECHON enra a ER a R ae dd 3 PiIEr Construction ea een see ae alas hanga a ap Rae 3 Concrete selecti n umas atoa ale etd oy Aueh ee AA ay Mave de 3 Vault wall decoupling socer reer parae ra EEEa EEEE OE EEEE ERa 4 Thermal insulation soto rondar ta a SEG UA o gg ag 4 Cable desiere win Ae Ree ds Re DER ADO pao ds Beh do aa dao eek a ates 4 installation se obio sesta Saia das eV Sad een eee dA RAS See he 5 UNPACKING oe 2decces a QUE arara e
3. Chapter 3 Installation Figure 3 2 Example of good sensor alignment 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 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 Caution Fibreglass insulation may irritate skin Use gloves when handling fibre glass batt insulation The Trillium 240 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 3 gt Wrap a layer of approximately 2 Scm about 12 30cm wide by 3 Im long snugly around the Trillium 240 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 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
4. 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 15672R3 2005 12 09 Trillium 240 Seismometer 21 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 240 which 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
5. see Chapter 1 Introduction 24 Trillium 240 Seismometer User Guide 15672R3 2005 12 09 Specifications This section lists the specifications of the Trillium 240 A 1 Technology Topology Symmetric triaxial Feedback Coil magnet force feedback with capacitive transducer Mass centring Automatic mechanical recentring can be remotely initiated Levelling Integrated bubble level adjustable locking levelling feet Alignment Vertical scribe marks for East West Precision holes for 5 16 alignment rods for North South A 2 Performance Self noise See Figure 4 3 on page 18 Sensitivity 1196V s m 0 5 Bandwidth 3dB points are 244s and 207Hz 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 19 Lower corner damping relative to critical 0 707 Output impedance 2 1500 1 Temperature 10 C without recentring Tilt Operational tilt range 1 15672R3 2005 12 09 Trillium 240 Seismometer 25 User Guide Appendix A Specifications A 3 Interface Connector 19 pin MIL C 28642 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 Calib
6. Table 4 3 Serial port commands Continued Command Description ShortPer Set sensor 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 is used when mechanically recentring the masses and is automatically invoked when the mass recentring is initiated The prior mode is restored when mass centring completes 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 240 second lower corner frequency SetXYZ Set sensor to XYZ mode SetUVW Set sensor to UVW mode Use the setxyz 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 t
7. 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 15672R3 Trillium 240 Seismometer 7 2005 12 09 User Guide Chapter 3 Installation Figure 3 3 Wrapping the Trillium 240 with fibreglass batt insulation 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 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 Make the insulation box large enough that it is not touching the sensor cables or fibreglass insulation Cut a groove in the bottom of one edge of the box to allow the sensor cable to exit at the appropriate point Seal the box joints properly For rigid foam without a foil coating glue the joints using polystyrene adhesive or polyurethane resin taking care to leave no gaps For rigid foam with a foil coating you can tape the join
8. cen tring operation and the previous mode is automatically restored when the centring operation is complete 3 7 Installation checklist This checklist can be used as an aid when installing Trillium 240 U 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 Cable is connected to the sensor and the digitizer U cable is strain relieved to the pier L cable is not touching the sensor case U Thermal insulating box and fibreglass insulation are in place U Thermal insulating box is not touching the sensor cables or fibreglass insulation U Thermal insulating box is weighted down U Masses are centred after temperature equalization at least 6 hours post installation 15672R3 2005 12 09 Trillium 240 Seismometer 1 1 User Guide Chapter 3 Installation 1 2 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09 Operation This chapter provides operating parameters and instructions for the Trillium 240 4 1 External connector The Trillium 240 connector is a 19 pin male military circular type hermetic connector The pinout is given in Appendix B 4 2 Sensor power The Trillium 240 can be powered using a DC source that can sustain 9 V to 36V 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 l
9. 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 Check sum 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 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 240 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
10. sensor channels signals U MP V_MP and W MP referenced to AGND e Ifthe values are outside the 3 5 V range the sensor may not be able to report seismic signals properly For this condition mass centring must be done e Ifthe values are within the range 3 5 V but not within 2 V range the sensor is sufficiently centred that it will report seismic signals properly However it is strongly recommended the masses be recentred e Ifthe values are within the range 2 V but not within the 0 3 V range the sen sor 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 fur ther ambient temperature changes For this condition centring the masses is recommended if it is convenient to do so 15672R3 Trillium 240 Seismometer 9 2005 12 09 User Guide Chapter 3 Installation e Ifthe 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 2 2 How to initiate mass centring You can initiate mass centring using either of these two methods Pull the MC RX pin high for at least 1 second referenced to DGND gt Issue a Center command using the RS 232 digital interface see Section 4 9 on page 20 3 6 3 Continuous electronic mass recentring Continuous electronic mass recentring compensates for gradual changes in tempera ture up to a range of 10 C difference from when
11. tilt than it had when it was last centred 3 6 2 1 Choosing when to initiate mass centring While mass centring can be done immediately after installing and levelling the Trillium 240 it is best to initiate mass centring again at least 6 hours after installa tion when the temperature has fully equalized This ensures the unit will then be able to tolerate up to 10 C range variation in ambient temperature without requir ing recentring It is best to initiate mechanical mass centring when the ambient temperature is roughly in the centre of its expected range rather that at one extreme or the other to make the most of the usable 20 C range the unit can tolerate without mechani cal recentring Mass centring should only be done when interruption of good quality seismic data can be tolerated as there are temporary effects on the output signal When the mass centring motors are operating the sensor s transfer function is set to a short period mode and the motion of the boom during the recentring is very evident in the output signal When the mass centring operation is complete the sensor reverts to the mode it was in before mass centring was initiated generally long period mode At this time there may be a transient superimposed on the output signal that takes some minutes to decay To determine whether mass centring needs to be done you can check the voltage readings on the mass position outputs for each of the three
12. 592 5929 15672R3 Trillium 240 Seismometer 1 2005 12 09 User Guide Chapter 1 Introduction 2 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09 Preparation This chapter provides general preinstallation guidelines for the Trillium 240 These guidelines are intended to help achieve the best possible performance but some guide lines 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
13. 672R3 2005 12 09 32 Trillium 240 Seismometer User Guide Appendix D Alignment Features Figure D 2 Alignment features bottom view 250 210 14 wee 120 00 we I 128 27 1 2532 120 00 120 00 49 45 All dimensions are in millimetres unless otherwise noted 15672R3 Trillium 240 Seismometer 33 2005 12 09 User Guide Appendix D Alignment Features 34 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09
14. ECHICANONS a carnais dp Ge aa Soe ba 25 Technology asas A RE A q A ees 25 Performante siis etena cus ste BIS cans AAR CAE Re ak nts aorta a 25 Interface 32 2 Ge ea a en Oo a ne Bat nun ee 26 Powers as Co N De Da a OTE Cb Ao a a EP E 26 Physical Fr ea a Bee ale 26 Environmental pida re cat s q a De RE da De eta a ara CESTO afta Re 26 Connector PINOUT sms a Sd E dA he 27 Genetic Sensor Gable citas ar a Ae 29 AlGniMene Features srs anais ale e e ah 31 Figures 3 1 3 2 4 1 4 2 4 3 4 4 D 1 D 2 Fibreglass batt insulation under the Trillium 240 0 0 eee 6 Example of good sensor alignment 0000 7 Wrapping the Trillium 240 with fibreglass batt insulation o oo o oooo 8 Sensor axis orientations eo ai ra i eee eee 15 Nominal frequency response 0000 000 17 Trillium 240 self noise ee eee nenn 18 Trillium 240 performance 0200 19 Alignment features top view 0 0 32 Alignment features bottom view 0 0 nennen nenn 33 Figures Tables 3 1 Mass position output voltage indicating need for mass centring 4 1 Axis orientation and polarity of XYZ outputs 0000 00 14 4 2 Poles and zeroes e Schad shoe tacks Ay et edad daa 16 4 3 Serial port commands 0 0 cc ee eee eee eens 21 B 1 Connector pinout naasse aeaaaee eee 27 C 1 Generic sensor cable wiring for CBL13942R2 0 0 0 0 0 aea 30 Table
15. 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 lt Modes gt 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 The lt Range gt lt Positions gt and lt Zeros gt numbers pertain to the mass recentring stepper motors The lt Range gt number is the full range in steps the mass positioning stepper motor can traverse between the two optical limit switches This is measured and set at the factory for each axis The lt Positions gt number is the current position of the stepper motor rel ative to the midpoint of the total range A number close to zero means the mass positioning mechanism is near the midpoint of the range and has lots of room for further adjustment A positive or negative number close to half the lt Range gt number means the mass positioning mecha nism is near to the limit of its adjustment range The lt Zeros gt number is the position of the stepper motor which corre sponds to the sensor being level If the lt Position gt number is close to the lt Zeros gt number for all axes the sensor is close to nominally level The lt Zeros gt number is set at the factory for each axis 15672R3 Trillium 240 Seismometer 23 2005 12 09 User Guide Chapter 4 Operation
16. and again at least 6 hours after installation when the temperature has fully equalized This ensures the unit will then be able to tolerate up to 10 C range variation in ambient temperature without requiring recentring 2 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 1 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09 Chapter 3 Installation Table 3 1 Mass position output voltage indicating need for mass centring Mass position output voltage Need to centre the masses outside the 3 5V range yes within the range 3 5V but not within 2V range strongly recommended within the range 2V but not within the 0 3V range recommended if it is convenient mass positions are all within the range 0 3V no although it can be done if desired 3 Initiate mass centring by pulling the MC RX pin high referenced to DGND pin R for at least 1 second This will initiate mass centring on all three axes in sequence first axis U then V then W The time for the operation to complete varies from a few seconds to at most 5 minutes but is typically less than 1 minute 4 Observe the voltage readings on the mass position outputs to confirm they are now within the 0 3V range Note that the sensor is temporarily put into short period mode during the
17. cal outputs XYZ The mass positions are zeroed by initiating the automatic mass centring feature which uses stepper motors to precisely tension the spring See Section 3 6 on page 8 for a discussion of these sig nals If the mass positions are all within the range 0 3 V then there is no need for recentring Otherwise follow the procedure in Section 3 6 4 Mass centring procedure on page 10 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 pin to the MC 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 e Data Bits 8 e Parity None e Stop bits 1 e Flow Control Xon Xoff 3 If you are using a terminal emulator program enable these settings e Echo typed characters locally The Trillium 240 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 0x0D 4 Once the sensor is powered up and an appropriat
18. d through the cable or else a ground loop will be created See Appendix B for connector pinouts 4 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09 Installation Once the vault has been prepared use the procedures described in this chapter to install the Trillium 240 Section 3 7 on page 11 provides a generic installation checklist 3 1 Unpacking Trillium 240 is shipped in a very sturdy triple wall coated cardboard box with custom cut cushioning foam gt 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 3 2 Optional thermal insulation To maximize long period performance we recommend wrapping fibreglass batt insu lation around and under the Trillium 240 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 Two methods of alignment are possible with the Trillium 240 vertically scribed marks on the East West axis and 5 16 diameter holes on the North South axis To level the Trillium 240 use the three adjustable height feet with lock nuts and the levelling bub ble on the cover For the most precise alignment possible two 5 16 diameter holes aligned to North South are provided in the sensor base into which 5 16 alignment rods can be fitted Howe
19. discovery 2004 01 turtle For information on RDF in general see http www w3 org RDF ReadUC Read th calibration parameters user Use the ReadUC command to display calibration information stored using the WriteUC command Trillium 240 Seismometer User Guide 22 15672R3 2005 12 09 Chapter 4 Operation Table 4 3 Serial port commands Continued Command Description Soh Report state of Use the SOH command to view state of health information as listed below health lt SOH gt lt Manufacture gt Nanometrics Inc lt Manufacture gt lt Product gt Trillium Firmware lt Product gt lt Version gt 3 30 lt Version gt lt Temperature gt 26 22 lt Temperature gt lt Mass gt U 0 030 V 0 497 W 0 063 lt Mass gt lt Adc gt U 14 V 225 W 29 lt Adc gt lt Modes gt Period Long Channel XYZ lt Modes gt lt Positions gt U 380 V 66 W 110 lt Positions gt lt Zeros gt U 0 V 0 W 0 lt Zeros gt lt Range gt U 7043 V 7371 W 7151 lt Range gt lt SOH gt lt Version gt The version of the firmware that is currently running lt Temperature gt The temperature near the main electronics PCB which is located in a chamber near the top of the unit The temperature of the axes will likely be different from this The mass positions for each axis U V W These are reported in two forms lt Mass gt decimal numbers with a 4 2 range that roughly corresponds to the output voltage at the U
20. e 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 turn 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 2 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09 Chapter 4 Operation Nanometrics Trillium User Menu Version 3 30 Program A KKKKKKKKK AAA AR RR KH KH KH TH TH KK TH TH RR TH TH TH RAR AA TH KH AA KH A A ASA 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 Set XYZ Set sensor to XYZ mode SetUVW Set sensor to UVW mode Ce
21. evel 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 that approaches the sensor s maximum clip level may draw as much as 2 W peak the average power consumption would be much lower The mass centring operation will draw additional power up to an incremental 2W while the motors are operating 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 2Q 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 such 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 9V to reliably power the sensor for maximum seismic signa
22. he default Note that this mode is also set by the UVW TX input line when the sensor is not in Serial Transmit mode The sensor responds to whichever command serial port or control line last signalled a change Center Center all masses or u v w You can use the Center command with or without parameters Without parameters Center initiates mass centring for all channels which can also be initiated by pulling the MC RX pin high for at least 1 sec ond referenced to DGND With a parameter u v or w Center will centre the specified axis without disturbing the other axes for example Center V centres the V axis only CheckSum Print check sum values for both program A and B Use the CheckSum command to check the firmware checksums of both partitions and what they should be This is useful to ensure there is valid code in each partition for example before switching to the alternate firmware partition 4 10 Troubleshooting and maintenance The Trillium 240 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 The automatic mass tensioner mechanism is designed to be jam proof In the unlikely event the sensor does not operate correctly please contact Nanometrics support
23. igure 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 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 5 Align the sensor precisely to East West by aligning the line drawn on the pier with the vertical East West 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 6 After you have aligned the sensor to East West 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 6 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09
24. in a seismic pier should be as homogeneous as possible to avoid inducing tilts due 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 15672R3 2005 12 09 Trillium 240 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 tu
25. in the orientation of the Trillium 240 s individual sensor axes The second equation is implemented electronically when the Trillium 240 is in XYZ mode Alternatively seismic data may be digitized with the Trillium 240 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 240 Seismometer 1 5 15672R3 User Guide 2005 12 09 Chapter 4 Operation 4 5 Frequency response The frequency response of the Trillium 240 can be measured using the calibration coil The measured response is the product of the calibration system s first order low pass response and the sensor s own response The nominal Trillium 240 response is obtained by dividing the nominal sensor calibration result by the calibration system s transfer function the three frequency response functions are shown in Figure 4 2 The calibration system s low pass response cancels the zero at 161 rad s in the sensor s transfer function when the sensor frequency response is measured using the calibration coil The nominal poles p zeroes 7 normalization factor k and normalization fre quency of the Trillium 240 are shown in Table 4 2 These parameters define the trans fer function according to this equation e z V s ar n F s Fa S sens
26. ls when using a 50m cable 15672R3 2005 12 09 Trillium 240 Seismometer 1 3 User Guide Chapter 4 Operation 4 3 Control signals Trillium 240 has 5 digital control inputs MC 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 5V at a cur rent greater than 0 1 mA enables the relevant functionality while any voltage less than 1V ora high impedance disables it All inputs can tolerate at least 15 V except for UVW TX which can tolerate voltages from 7 V to 15V 4 4 Output signals The sensitivity specified in Table 4 2 on page 16 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 300Q 1 150Q each output A control signal switches the Trillium 240 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 cor
27. m lt gt M3 5 at 10 km A M5 5 at 10 km M1 5 at 100 km M3 5 at 100 km 60 M5 5 at 100 km M7 at 100 km M6 at 3000 km M8 at 3000 km 80 Trillium 240 Self Noise Trillium 240 Clip Level Dig Noise Max Gain Dig Noise Min Gain Dig Clip Max Gain 100H Dig Clip Min Gain 140 160 Peak Velocity in Octave Bandwidth dB wrt 1 nf s 180 200 Bsa mest Ed 220 a psi po il po al po L a 1 10 10 10 10 10 10 Frequency Hz 4 7 Calibration Calibration inputs are provided to allow for relative calibration of the sensor across fre quency and over time Since the Trillium 240 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 15672R3 Trillium 240 Seismometer 1 9 2005 12 09 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 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 verti
28. mechanical mass centring was last initiated If the temperature changes more than 10 C the unit may need to be mechan ically mass centred 3 6 3 1 Mass recentring status The mass position status is reported via analog signals U_MP V_MP and W_MP ref erenced to AGND pins E F S and V respectively which operate roughly in the range 4V A OV signal means the axis boom is perfectly centred A signal exceeding 2 V indicates mechanical mass recentring should be initiated These signals respond very slowly to changes in tilt mass position or temperature when the sensor is in the normal operating long period mode but respond almost instantly within a second when the sensor is set to short period mode The mass position status is also reported digitally via the RS 232 serial interface see Section 4 9 on page 20 3 6 4 Mass centring procedure When using a Nanometrics digitizer such as a Taurus or Trident that is connected to a network you can read the mass position status and initiate mass centring remotely For the Taurus use options in the Sensor page either locally or on an external browser The Taurus also provides a mass auto centring feature For the Trident use options on the Nanometrics UI Trident gt Operation gt Instrument page or use NaqsView 1 Install and level the Trillium 240 as precisely as possible gt For best results centre masses immediately after installing and levelling the Trillium 240
29. neric 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 YtNt P2 CH2 WHT 2 P1 A Y V 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 S W MP P2 EXT SOH1 BRN 6 P1 V_MP P2 EXT_SOH2 BLK 6 P1 SHELL P2 SHELL DRAIN 6 P1 E U_MP P2 EXT_SOH3 ORG 7 P1 AGND P1 CH1GND BLK 7 P1 SHELL P2 SHELL DRAIN 7 P1 PWR P2 SEN 12V RED 8 P1 G PWR P2 SENRTN WHT 8 P1 SHELL P2 SHELL DRAIN 8 P1 D UVWITX P2 CTRL1 RED 9 P1 MC RX P2 CTRL2 GRN 9 P1 R DGND P2 DGND DRAIN 9 P1 SHELL P2 SHELL BRAID 3 Trillium 240 Seismometer User Guide 15672R3 2005 12 09 Alignment Features See Figure D 1 and Figure D 2 for top and bottom views of the Trillium 240 showing the relative orientation of the East West and North South alignment features 15672R3 Trillium 240 Seismometer 31 2005 12 09 User Guide Appendix D Alignment Features Figure D 1 Alignment features top view SENSOR CONNECTOR Tor T7 _ BUBBLE LEVEL 15
30. nter Center all masses or u v w CheckSum Print checksum value for both program A and B KKKKKKKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KK KKK KKK KKK KKK KKK KKK KKKKKKKKKKK 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 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 Tx0ff 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
31. or k m EQ 3 6 n Where the normalization factor is defined as follows 1 k EQ 4 Te 2 74 2 A ea br 0 2 7 n Table 4 2 Poles and zeroes Parameter Nominal values Units 0 K Zeroes 5 rad s n 108 161 0 01815 0 01799i 173 Pn Poles _196 231i rad s 732 1415i k Normalization factor 2 316 x 10 Daido Passband sensitivity at 1Hz 1196 5 V s m fo Normalization frequency 1 Hz 1 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09 Chapter 4 Operation The transfer function is approximately flat out to 240s and rolls off at 40dB decade below the lower corner frequency as shown in Figure 4 2 Figure 4 2 Nominal frequency response 10 Magnitude dB o an das Pr 135 H Seismometer Calibration 180 Combined Response N 10 10 10 10 Frequency Hz 4 6 Self noise Typical Trillium 240 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 shown is the typical level of instrument self noise assuming proper instal lation To achieve best performance for any sensor meticulous attention to detail must be paid to choice of site vault design and sensor installation The New Manual of Seis mological Observatory Practice LASPEI 2002 has a good disc
32. p a ne Maye RD Dune ep en ae a 5 Optional thermal insulation 00 0000 5 Orientation and levelling 0 0 0c eee 5 Installing the sensor cable 0 0 0 0 ce ete ete eee 7 Installing the thermal insulation 00 0000 7 Optional Install the fibreglass batt insulati0N oooooo ooooooooooo o o 7 Install the rigid foam insulation box 2 2 ee 8 Mass centring ysis ae vat eee a A A ra oe a ed a La Se 8 1665 0 0 ere a Pen a et 9 Mechanical mass centring ereo teap pa ka E EE AE eee 9 Choosing when to initiate mass centring nasasa aaaea 9 How to initiate mass centring 2 2 aaua aaae 10 Continuous electronic mass recentring 0 6 0 0000 eee tee 10 Mass recentring Status vd AA 10 Mass centring procedure lcciicciiici een nenn 10 Installation checkliste rssi reure Seiad caras 11 Operation ren AA SA SO E A 13 External Connectors it e a A Rr 13 Sensor POWER 28 2 ee Lee A OA Be RMR ie A e 13 Control SIN Sat cir ea pa A RO Hae EA Cae daar ye ehe 14 Outpu tsignalS erered ars eee oie ie ee a a 14 Frequency response 2 e tee eee 16 SENHAS sey vine ch Dl Re ee a eae et a 17 Galibration e aa 20 tea ae ala nenn Dean ln nie P RP re a a Ake 19 state of Heallt 22 20 decc nee oe jie dite a ARES Ged Seen ties 20 Connecting and configuring the serial port 0 2 0 ee 20 Troubleshooting and maintenance 0 0 0 ee eee 24 Contents OP
33. ration input Remote 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 output Power consumption 650mW typical at 15V input Protection Reverse voltage protected Self resetting over current protection No fuse to replace A 5 Physical Diameter 25cm Height 26 5cm without levelling feet 28 6cm with levelling feet at minimum extension 29 5cm with levelling feet at maximum extension Weight 14kg Parasitic resonances None below 150Hz 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 0 to 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 2 Trillium 240 Seismometer User Guide 15672R3 2005 12 09 Connector Pinout The Trillium 240 connector is a 19 pin male military circular type hermetic connector The pinout is given in Table B 1 Table B 1 Connector pinout
34. re stable site they must have some form of thermal insulation Insulation serves 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 240 and then installing a rigid foam insulation box See Section 3 5 Installing the thermal insulation on page 7 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 MC 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 240 so if these signals are already connected at the digitizer AGND should not be connecte
35. respondence to the direc tions 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 To select the sensor outputs gt To select the UVW outputs pull the UVW TX pin high 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 then used as the RS 232 serial TX output signal See Section 4 9 Connecting and configuring the serial port on page 20 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 14 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09 Chapter 4 Operation Figure 4 1 Sensor axis orientations This arrangement results in the following transformation equations u 1 2 0 2 x v J6 SN ab 0 8 le 2 1 1 u yl a 0 8 8 v EQ 2 z 56 w The first equation is implemented mechanically
36. s vi Introduction Trillium Model 240 is a three component very broadband low noise seismometer suit able for portable and fixed applications Its extended low frequency range useful out to beyond 1000 seconds low noise and wide dynamic range make it ideal for teleseismic studies as well as for regional and local events The Trillium 240 has an internal fully automatic mass recentring capability which facilitates both local and remote recentring 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 240 If you need technical support please submit your 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 To Support 613
37. ts with packing tape taking care to leave no gaps 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 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 240 has an automated mechanical mass centring capability that uses a pre cision stepper motor to centre the boom of the pendulum of each axis exactly at the null point The motor adjusts the tension on the spring which supports the boom to com pensate both for tilt from absolute level and for the ambient temperature in which the unit is operating 8 Trillium 240 Seismometer 15672R3 User Guide 2005 12 09 Chapter 3 Installation As well the sensor automatically recentres the masses electronically to compensate for gradual changes in temperature up to a range of 10 C difference from when mechan ical mass centring was last initiated 3 6 1 Tilt tolerance The Trillium 240 is designed to tolerate a tilt within the range 1 of level If the unit is tilted beyond this range the mass centring may not be able to recentre the booms and the unit will not operate correctly 3 6 2 Mechanical mass centring The operation of mass centring typically takes less than 1 minute It may take up to 5 minutes if the unit is compensating for substantially different
38. ussion of the relevant 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 F and T H Heaton 2002 Potential Advantages of a Strong motion Velocity Meter over a Strong motion Accelerometer Seism Res Lett 73 332 342 15672R3 2005 12 09 Trillium 240 Seismometer 1 7 User Guide Chapter 4 Operation best practices see the publisher s site http www gfz potsdam de pb2 pb21 for infor mation on the NMSOP Figure 4 3 Trillium 240 self noise PSD dB wrt 1 m s Hz 100 NLNM 110 MLNM see Trillium 240 120 10 Ti ap ll Te 150 160 e Pd Pd e e a s A 190 200 3 pr ad DO ab NE 10 10 10 10 10 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 1 Trillium 240 Seismometer User Guide 15672R3 2005 12 09 Chapter 4 Operation Figure 4 4 Trillium 240 performance 20 TT 40 O M1 5at10k
39. ver the East West alignment marks will be precise enough for most installations See Appendix D for top and bottom views of the Trillium 240 showing the relative ori entation of the East West and North South alignment features 1 Draw a line on the pier parallel to East West The East West line or North South line if you are using the alignment rods drawn on the pier must be aligned to true East North If you are using a magnetic compass account for the local magnetic declination when drawing the line 15672R3 Trillium 240 Seismometer 5 2005 12 09 User Guide Chapter 3 Installation Caution Fibreglass insulation may irritate skin Use gloves when handling fibre A 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 240 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 240 level ling feet Figure 3 1 Fibreglass batt insulation under the Trillium 240 3 Take the Trillium 240 out of its box and place it gently down on the pier aligned approximately to East West The West marker line on the Trillium 240 base is the one just to the left of the sensor connector F
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