Home

User`s Guide

Contents

1.
2. m Soldering iron approx 50 watts m Solder m Wire cutters m Wire strippers PVC insulating tape Utility knife Heat gun 15 m 3 digit DVM with 200 ohm range or equivalent Figure 2 4 Parts for the recorder end mating connector assembly Installation Basics Note In place of the 3 8 foil you may have received two 1 wide foil tapes If your kit contains this substitution then make tape that is approximately 3 8 wide as follows 1 Divide one of the 1 x 3 pieces into thirds the long way as shown in the middle grouping in Figure 2 5 so you have three 3 long pieces Divide two of the approx 3 8 wide strips into 1 long segments as shown in the bottom grouping in Figure 2 5 When finished you should have 6 pieces approx 3 8 x 1 and 1 piece approx 1 4 x 3 Figure 2 5 Preparing 3 8 wide foil tape from 1 foil tape With the parts you need pulled out of the kit and the proper width of tape prepared begin assembling the recorder end mating connector FBA 23 Force Balance Accelerometer Strip off 3 4 of the outer black rubber tubing on one end of the Shrink N Shield tubing shown on the right side of Figure 2 4 While stripping this off be careful not to nick the remaining tubing or the cloth screen mesh Gather the parts listed in Table 2 2 and slide them over the cable s outer jacket a couple of feet up so they are out of the way until needed Slide them over the jacket in t
3. 21 22 23 24 Slide the Thermofit tubing connector back shell and braid over the outer jacket of the cable Remove 3 1 2 of the outer jacket from the end of the cable Remove 3 1 8 of the overall foil shield Remove 3 1 8 of the outer jacket from each of the 3 shielded twisted pairs white red white green and white yellow Remove 2 3 4 of the braid shields from the end of each of the three twisted pairs Attach and solder 3 of 18 AWG black wire to each of the three braided shields Slide a piece of the 1 4 shrink tubing over the braided shield and the black wire solder joint Shrink into place Cut off 3 1 8 of the orange and white wires leaving them 3 8 longer than the overall shield Apply the 1 8 shrink tubing over the ends of the orange and white wire and shrink into place Slide the Teflon tubing over the drain wire leaving it positioned 1 8 from the wire end Using Drawing 109712 as a guide insert the wires through the connector grommet Strip wires 1 8 and solder tin Solder the wires into the connector starting at the bottom and working upward Push the grommet forward onto the connector Wrap one layer of PVC insulating tape between the overall foil shield and the back of the connector grommet Starting from the end of the overall cable jacket use the three 1 x 2 1 2 lengths of foil tape to wrap the cable until you reach the back of the connector gr
4. Polarity Conventions ii edge p prat tu 6 Electrical Interface awe n reet east 7 6 Advanced Installation Topics GE Compliant Installations AS ei ade 1 Long Cableados 1 Cable Assembly with P N 700045 sss 1 CE Cable Assembly u seem Maas u 2 Per Supplied Cable ses Le ste 5 od kvar 6 Use with Non Kinemetrics Data Loggers ooooocnccnnncccooccconacannconnoos 7 Prva 7 Output Voltage aS E Calibration Sequens cce gelebt naa a 8 Gro ndinE eieren ue Bec ve ote baec bibe v v oed Tabs 8 FBA 23 Force Balance Accelerometer Safety 7 Appendix Tables and Figures Table 2 1 Assembly kit parts required for the Altus recorder mating connector assembly 10 Table 2 2 Part order recorder cable end 12 Table 2 3 Parts required for the FBA 23 end mating connector ASSEMBLY Een otii t ee E Ead hm 21 Table 2 4 Slide parts over jacket in this order 22 Table 3 1 Overshoot Rates un 7 Table 6 1 Required parts for the Altus recorder mating connector assembly ainia 2 Table 6 2 Required parts for the FBA 23 end mating connector assembly nn aeg 4 Table 6 3 FBA 23 cabling voltage drop calculator 6 Table 7 1 FBA 23 Specifications sense 1 Figure l r The RB Ir ee ran an 2 Figure 2 1 Dimensions of the FBA 23 esee 5 Figure 2 2 Anchoring the FBA 23 sse 7 Figure 2 3 FBA 23 to Altus recorder cable 9 Figure 2 4 Parts for the recor
5. quipement au logiciel ou d autres propri t s WARNING Indique une condition ou op ration qui peut entrainer des blessures corporelles ou la perte de la vie Les deux derniers termes mentionn s peuvent apparaitre sur les quipements de Kinemetrics que vous avez acquis mais pas n cessairement indiff remment il est conseill de prendre au s rieux les avertissements de ce manuel FBA 23 Force Balance Accelerometer Safety Precautions Sp cifiques Observez toutes les pr cautions suivantes afin d assurer votre s curit personnelle et d viter des d g ts aux composants de votre capteur FBA 23 Alimentation Le FBA 23 doit tre aliment avec un courant de 12 VDC fourni par l enregistreur ou par votre propre syst me d alimentation Si vous alimentez le FBA 23 avec l enregistreur connectez l enregistreur en utilisant le syst me d alimentation fourni par Kinemetrics et decrit dans le manuel d utilisation d livr avec l enregistreur Pour fournir une alimentation au FBA vous avez besoin d une source faible bruit 12V avec une mise a la terre ad quate et qui remplit les conditions de la reglementation locale Option Systeme d alimentation fourni par l utilisateur Si vous fournissez votre syst me d alimentation vous devez vous assurez que le syst me fournit une tension et un courant requis par le FBA 23 Veuillez noter que vous serez seul responsible pour la s curit de votre systeme d ali
6. sse 4 Free Field Mounting ee 4 Mounting the BAS oue bou tire 5 Using Kinemetrics Anchore ue Ea As 6 Mounting in a Structure avse 7 Orienting the FBA 23 ue teen ne teet rene 8 Leveling the BEA 23 un n ner 8 Cable Assembly aca b es te tela ad ota dec ER UG UR 8 CE Compliant Cables dues tst t tarea leiste 26 Connecting the FBA 23 to a Recorder 26 3 Operating Basics Operating Concepts tin dea dees saci Han ie d o Dod innen 1 Power to the FBA den ei 2 Zero Adjusting the FBA ns ea 3 Methods of Measuring the DC Offset 3 Performing the Zero Adjustment distintas eterno 4 Performing a Functional Test on an FBA with an Altus Recorder 6 4 Maintenance Recommended Maintenance oococnnnnnnnnnnnnnnnnnnnnnnnnnnnonononononononononoss 11 Adjust the Accelerometers near Reiki 11 Complete Functional Test esters 11 D siccant Replacement ec nent dr ont 11 Troubleshooting and Repair 11 Modification of Range or Natural Frequency 12 Calibrador 12 5 Reference Theory of Operation nadas 1 Pole Zero Representation of the FBA 23 sess 3 The Dynamic System ses aa 3 Theoretical Second Order Tranfer Function 4 Absol te G Meat nes 4 Practical Damping amp Natural Frequency sssse 5 Second Order Transfer Function Poles for Nominal FBA 23 Parameters roroossnennnnnvnnnnvvevernnnnnnnnnvnevnnnnnnnnnnnnene 5
7. with the other DVM lead check that all other pins in that connector are infinite with respect to pin L 2 Atthe FBA 23 end of the cable have another technician take the white black wire pair and use a test lead jumper to connect the white wire to the black wire 3 When that is done the DVM at the recorder end should show that pin L is now connected to pin M The DVM should measure lt 2 5Q per 100 of cable If it does have the other technician remove the test jumper at the FBA 23 end of the cable 4 Disconnect the DVM lead from connector pin L on the recorder end and with the other DVM lead still connected to pin M confirm that pin M is infinite with respect to all the other connector pins You have now buzzed out the top two connections L and M shown in Figure 2 12 for the two wires in the white black pair Now repeat Steps 1 FBA 23 Force Balance Accelerometer 2 19 2 20 through Step 4 but test connector pins A and B and the two wires in the green black pair Follow Steps 1 through 4 for each pair of connector pins and wire pairs in he remaining five pairs of wires and 10 connections shown in Figure 2 12 Carefully check that all other pins in the connector are infinite with respect to the connector pin you are testing that the two wires in each pair can be linked at the FBA 23 end without problems and that the pin is infinite with respect to all the other connector pins As you test follow the right end of Figur
8. 50 10 100 025 05 1 0 5 1 100 As an example of the full TF a 50 Hz 1g FBA 23 would have the following nominal poles FBA natural Pole dex pus frequency Hz P1 Real component rad s 50 222 1 1 222 1 1000 Imaginary component 222 1 222 1 rad s Note To get the TF representation reduced to a constant input displacement compatible with the standardized GSE PAZ FBA 23 Force Balance Accelerometer 5 5 calibration header CAL1 format two zeros at the coordinate origin of the s plane must be added to the above transfer functions FBA natural frequency Hz Zero Zero Z2 and full scale sensitivity g Z1 Real component rad s EIE E Imaginary component All rad s Kinemetrics web site contains the latest information on poles and zeroes for all Kinemetrics Instruments and sensors Polarity Conventions The direction of response for a positive acceleration to the case for each axis is shown in the figure below In the FBA 23 positive acceleration is defined as that motion which causes the mass to move toward the permanent magnet in the pole piece Thus for the Longitudinal sensor positive acceleration corresponds to the direction of the orientation arrow Kinemetrics FBA 23 complies with polarity standards for seismic sensors in the Special Report of the Subcommittee on Polarity Standards Society of Exploration Geophysicists 1975 A positive acceleration upward motion of the case for the v
9. Basics Figure 2 9 The drain wires twisted together uy A CT _ 4 tt 9 Wrap and solder the single drain wire to the stripped area of the black wire then trim off all excess drain wires as shown in Figure 2 10 Figure 2 10 Drain wire to black wire connection L gt 10 Apply 1 4 diameter by 1 4 long shrink tubing over the soldered area of the drain wires and black wire as shown in Figure 2 11 The cable is now ready for 3 8 x 3 foil tape wrapping 1 Tightly wrap the foil tape around the twisted together drain wires in the center as shown in Figure 2 11 2 While gathering the twisted wire pairs toward the center of the cable bring the tape tightly over the outside of all of them See Figures 2 11 2 12 and 2 13 FBA 23 Force Balance Accelerometer 2 15 Figure 2 11 Outer foil tape and drain wire shrink tubing 3 Now insert the twisted pairs of wires into the grommet Use the schematic in Figure 2 12 to find the proper wire to solder cup locations Be sure to follow the proper half of the schematic below depending on whether you are currently assembling the recorder end or the FBA 23 end of the cable Figure 2 12 Schematic of external FBA 23 cable to both mating connectors FBA 23 ALTUS RECORDER EXTERNAL FBA INPU tu
10. The common connection should return to the power supply through only one path If you are using a separate mains power supply for the FBA 23 be very careful that it does not provide a separate ground return through the AC mains ground to the data acquisition computer You should use a star ground configuration for your system with the FBA 23 power supply data acquisition system and PC all grounded at the same point Advanced Installation Topics 7 Appendix Table 7 1 FBA 23 specifications Type Triaxial force balance accelerometer Full scale range 1g 0 1g 0 25g 0 5g 2g and 4g are optional Natural frequency 50 Hz 90 Hz 100 Hz optional Damping 70 critical Full scale output 2 5V Zero offset Adjustable to less than 25 mV Cross axis lt 03 g g Linearity lt 1 of full scale Temperature span change lt 2 full scale Temperature zero drift lt 2 full scale Dynamic range gt 135 dB from 0 01 Hz to 50 Hz gt 145 dB from 0 01 Hz to 20 Hz RMS sinus clipped signal to octave bandwidth RMS noise as measured by the dual coherence method Power supply voltage 12 volts DC 10 mA quiescent Operating temperature 20 to 70 C Housing Watertight cast aluminum case with leveling feet and level Dimensions 2 75 x 5 5 x 5 5 66 x 130 x 130 mm Weight 5 2 Ibs 2 3 kg FBA 23 Force Balance Accelerometer
11. Usuario Si usted provee su propio sistema de poder carga usted tiene que estar seguro que el sistema proporciona el voltaje correcto y la corriente requerida por el FBA 23 bajo todo las condiciones de operaci n Usted es responsable por la seguridad de su sistema de carga Si usted deriva energ a de suministro principal usted tiene que asegurarse que ha provisto un polo a tierra adecuado para todo el equipo Si usted suministra sus propias bater as siga las recomendaciones de seguridad del fabricante Cableado y Polo a Tierra del Sensor En algunos casos el FBA 23 estar a una distancia lejos del registrador En estas instalaciones existe la posibilidad de una elevada diferencia de potencial entre dos localidades de polo a tierra debido ya sea a fallas en el alambrado del AC o corrientes de un extremadamente alto retorno de tierra Cuando el cable esta polarizado a tierra en uno de sus lados terminales un voltaje potencialmente letal puede existir entre el otro lado terminal del cable y el polo a tierra Considere este peligro durante la instalaci n y obtenga ayuda de un electricista calificado si este peligro existe No Opere en Atm sferas Explosivas El FBA 23 no proporciona ninguna protecci n explosiva para descargas est ticas componentes que generen arcos el ctricos No operar el equipo en una atm sfera de gases explosivos FBA 23 Force Balance Accelerometer Safety S curit Symboles amp Terminologie LN
12. at a high sampling rate of 1000 samples per second This removes any effects from the digital filters in the recorders and allows the sensor response to be directly observed The functional test consists of two input pulses that stimulate an acceleration applied to the CAL input of the FBA An undamp signal is enabled on the falling edge of the first pulse It is disabled just before the second pulse These signals result in the following effects on the FBA output On the rising edge of the first pulse the FBA will respond as a second order system with a damping of 0 6 0 7 A small overshoot of 4 6 9 5 will be observed on the leading edge The actual damping corresponding to various overshoot rates is given in Table 3 1 The sensor is undamped on the falling edge of the first pulse and responds as a lightly damped second order system The impulse will cause the sensor to ring at its natural frequency This ringing will die down in 0 5 to 1 5 seconds The system will again be damped on the leading and trailing edges of the second pulse and show the overshot of a damped system Figure 3 5 shows a functional test on a 50Hz FBA at 100 samples per second In this instance the bandwidth of the recorder is not sufficient to allow the ringdown to be seen Figure 3 6 shows the same sensor at 200 samples per second and the ringdown is clearly visible Figure 3 7 shows an SRT on a 50 Hz FBA with the ringdown clearly seen In this figure the natural freque
13. instructions in the next section on zeroing the T sensor FBA 23 Force Balance Accelerometer 3 3 5 When all the sensors have been zeroed remove the DVM leads and replace the cover Be sure that the cover is correctly aligned with the orientation arrow pointing away from the connector Take care not to pinch the sealing gasket Carefully tighten the 12 screws in an alternating pattern to evenly seat the cover on the gasket The screws should be tightened to a torque of 10 15 inch lbs Choice 2 The other method is to build a break out cable that allows you get to each of the wires in the FBA cable You can then measure all the voltages at this breakout cable This is the best method to use if you have multiple FBA 23s to install Be sure you are supplying the FBA 23 with 12 VDC going to the proper input Performing the Zero Adjustment Caution If you have an Altus series recorder its firmware will allow you to remove an offset from the data stream by subtracting a constant value from the data after it is recorded However you should only use this to remove a small residual offset If you remove a large offset you will reduce the instrument s recording range Refer to Figure 1 5 to see the three screws that provide access to the zero adjustment pivots To check the zero adjustment of the longitudinal accelerometer use one of the methods described above to measure the sensor s zero output voltage If the volt
14. longitudinal vertical and transverse inside a sensor casing The longitudinal accelerometer is aligned parallel to the orientation arrow on the case of the FBA 23 Each accelerometer is essentially identical except that only the vertical accelerometer has an active oscillator The carrier from this oscillator is supplied to the longitudinal and vertical accelerometer The figure below shows a simplified block diagram of the major components of each of the FBAs Figure 5 1 Simplified block diagram of an accelerometer inside the FBA 23 apacitive ransducer Undamp FBA 23 Force Balance Accelerometer Cont ro Transconductance gt Amplifier Am Analog Output Damping Capacitor Damp Undame ontro N Normally Closed 5 1 The FBA works as follows The oscillator applies an AC signal of opposite polarity to the two moving capacitor plates With the accelerometer zeroed and with no acceleration applied these plates are symmetrical to the fixed central plate and no voltage is generated on the plates An acceleration causes the coil and capacitive sensor plates which are one assembly mounted on mechanical flexures springs to move with respect to the fixed central plate of the capacitive transducer This displacement results in the signal on the center plate of the capacitor becoming unbalanced and an AC signal of the same frequency as the oscillator is passed to the amplifier The amplifier amplifies
15. orientation arrow points north 2 Place the washer on the 1 4 20 bolt 3 Insert the bolt and washer through the anchor hole in the FBA 23 until they engage the anchor 4 Tighten loosely and follow the instructions for levelling the unit Figure 2 2 Anchoring the FBA 23 4 2 3A 23 s see Sec A 7 7 SET Z N HU J y ES v A y E G 7 f f na E v Jase the y 8 miinimum ES QD FBA 23 EU Y 7 E P ZZ Jj ere tior A 8 north Z Mounting in a Structure To install the FBA 23 in an existing structure you may need to construct a custom mounting plate then bolt that plate and the FBA 23 onto the structure Note Before pouring concrete or attaching the FBA 23 to any floors or structural steel members determine the final directional orientation of FBA 23 FBA 23 Force Balance Accelerometer 2 7 Orienting the FBA 23 For installation in a structure the FBA 23 is normally aligned parallel to the structure s main axis Leveling the FBA 23 Cable Assembly Check the bubble level on top of the FBA 23 If the air bubble is centered in the ring no leveling adjustments need to be made Tighten the mounting bolt using a torque of between 30 70 inch pounds If the air bubble is not in the center of the ring loosen the mounting bolt and adjust the three leveling feet until the bubble is centered Retighten the mounting bolt using a torque of 30 70 inch pounds being careful to mai
16. overall foil shield 29 Remove 2 3 8 of the outer jacket from each of the 3 shielded twisted pairs white red white green and white yellow 30 Remove 2 3 8 of the braid shields from the end of each of the three twisted pairs 31 Cut off 2 3 8 of the orange and white wires leaving them 3 8 longer than the overall shield 32 Apply the 1 8 shrink tubing over the ends of the orange and white wire and shrink into place 33 Slide the Teflon tubing over the drain wire leaving it positioned 1 8 from the wire end 34 Using Drawing 109712 as a guide insert the wires through the connector grommet 35 Strip wires 1 8 and solder tin 36 Solder the wires into the connector starting at the bottom and working upward 37 Push the grommet forward onto the connector Advanced Installation Topics 38 Wrap one layer of PVC insulating tape between the overall foil shield and the back of the connector grommet 39 Starting from the end of the overall cable jacket use the three 1 x 2 1 2 lengths of foil tape to wrap the cable until you reach the back of the connector grommet 40 Slide the braid 20 forward until it covers the back end of the connector grommet and foil tape The braid shield should cover just up to the beginning of the connector threads 41 Mold the braid around foil tape wrapped cable and connector grommet 42 Slide the extension tube and connector back shell forward and tighte
17. sentencias identificando informaci n que Usted debe considerar cuidadosamente antes de dirigirse a la siguiente instrucci n u opci n Caution sentencias identificando condiciones o practicas que podr an resultar en dafio del equipo el software u otra propiedad WARNING sentencias identificando condiciones o practicas que podr an resultar en una lesi n personal o la perdida de la vida Los ltimos dos t rminos mencionados arriba podr an tambi n aparecer en el equipo Kinemetrics que Usted ha comprado pero no necesariamente FBA 23 Force Balance Accelerometer Safety indiferentemente Usted debe definitivamente tomar notas serias de las precauciones y advertencias en este manual Precauciones Especificas Siga las precauciones a continuaci n para garantizar su seguridad personal y prevenir dafios al FBA 23 Fuente del poder El FBA 23 debe ser alimentado con energ a ya sea desde un registrador o desde una fuente de 12V provista por el usuario Si usted planea alimentar el FBA 23 desde un registrador conecte el registrador a una fuente de poder cargador suministrado por Kinemetrics como se describe en cada manual del usuario para el registrador Para suministrar energ a directamente al FBA 23 usted necesita una fuente de poder de bajo ruido y regulado 12V el cual debe ser apropiadamente conectado a tierra y cumplir con todas las regulaciones locales que apliquen Sistema de PoderlCarga Provisto por el
18. the FBA 23 to the recorder Depending on the length required you may have purchased either Kinemetrics P N 700045 or the Belden cable stocked by Kinemetrics as P N 840356 m Solder with rosin core flux Heat shrink tubing 1 4 diameter cable tie wraps and electrical tape Mounting anchor supplied with the FBA 23 m Mating connector supplied with FBA 23 if you did not order the pre assembled cable from Kinemetrics m Cable Accessory Kits supplied with Altus recorders and FBA 23 for Belden cable Optional CE FerriShields supplied with CE certified Altus recorders Required Equipment m Battery powered Digital Volt Meter DVM Compass for checking the orientation of the sensors Camera to photograph the completed installations for the commissioning report recommended Mounting and Orienting the FBA 23 Free Field Mounting For a free field installation of the FBA 23 you will probably need a concrete pad or pier upon which to secure it To make sure the pad or pier is large enough compare its size with the dimensions shown in Figures 2 1 and 2 2 2 4 Installation Basics Figure 2 1 Dimensions of the FBA 23 Note Before pouring concrete or attaching the FBA 23 be sure the finished platform will line up with a true north south axis and true east west axis Pouring the platform in this orientation will help in making sure that the white orientation arrow on the top of the FBA 23 wh
19. this AC signal This error signal is then passed to the demodulator where it is synchronously demodulated and filtered creating a DC error term in the feedback amplifier The feedback loop compensates for this error signal by passing current through the coil to create a magnetic restoring force to balance the capacitor plates back to their original null position The current traveling through the coil is thus directly proportional to the applied acceleration and by sensing the voltage this current generates across the sensing resistor we can produce a correctly scaled output voltage from the final amplifier The FBA has two additional features to verify its calibration The sensor has a connection Ca to allow a calibration step to be applied to the sensor to simulate an impulse response This allows the damping of the sensor to be determined This signal is injected through a diode and must be a positive pulse of 2 5V When not in use this line must be connected to an electrical potential of 2 5V to 12V It must not be left open or noise can be injected into the system The sensor normally has a damping ratio between 0 6 0 7 but by applying a signal to the Undamp line the damping capacitor can be removed making the unit an approximation to a high Q second order system rather than a critically damped second order system If an impulse response is applied to the Calibration input the sensor will then ring at i
20. vertical accelerometer s pivot Caution This adjustment is very small not more than 1 Do not turn the accelerometer s pivot more than 2 The unit has a mechanical stop that prevents over rotation of the pivot Do not try to force the adjustment beyond this stop You will break the unit 2 With the screwdriver apply gentle pressure to the pivot until the voltage is between 25 mV and 25 mV If the reading is too positive turn the pivot clockwise but not more than 1 If the reading is too negative turn the pivot counterclockwise but not more than 1 3 Once the voltage reading is in the proper range remove the screwdriver and replace the access screw To check the zero adjustment of the transverse accelerometer use one of the methods described above to measure the sensor s zero output voltage If the voltage reading is more than 25 mV or less than 25 mV then the transverse T accelerometer offset requires zero adjustment To adjust the transverse accelerometer 1 Remove the T access screw then insert a small flat bladed screwdriver into the screw hole and into the slotted end of the transverse accelerometer s pivot Caution This adjustment is very small not more than 1 Do not turn the accelerometer s pivot more than 2 The unit has a mechanical stop that prevents over rotation of the pivot Do not try to force the adjustment beyond this stop You will break the unit 2 With the screwdriver
21. 7 we 7 REF N y INSULATING 40 AU VC TAPE i 3M 35 TYPE Items from the reference list in the figure above are in the assembly kit This kit contains items for attaching connectors on either end of the 840356 cable Separate them carefully according to the instructions below Some items are used on one end of the cable and not the other end Some items are interchangeable and can be used on either end of the cable Much of the assembly process is the same for either end of the cable Initial Assembly of the Altus Recorder End To assemble the recorder end of the 840356 cable open the assembly kit and pick out the parts listed in Table 2 1 and illustrated left to right in Figure 2 3 Keep the other parts in the assembly kit bag you will need them later To install mating connector P N 851119 you require the following Table 2 1 Assembly kit parts required for the Altus recorder mating connector assembly Part Name KMI P N Commercial P N Description of Item s Mating connector 851119 851 06EC14 19PN50 1 connector Foil tape 880699 1183 3 8 wide 6 pieces 3 8 x 1 Foil tape 880699 1183 3 8 wide 1 piece 3 8 x 3 Foil tape 880700 1183 1 wide 1 piece I x 3 Shrink tubing 850839 FIT 221 1 4 piece cut 1 4 long Shrink N Shield tubing 851366 SST 20 piece 3 long Thermofit tubing 851186 DWP 125 3 4 black 1 piece 3 4 long Required tools and supplies
22. Les symboles suivant peuvent figurer sur les quipements Kinemetrics ou dans ce manuel Signifie Attention Quand vous rencontrez ce symbole sur un instrument veuillez vous r f rer la section de ce manuel signal e par la m me marque Avant m me d effectuer la premi re op ration sur l instrument vous devez lire la section correspondante de ce manuel Faite attention si vous voyez cet symbole m Indique une mise la terre faible bruit Les objets portant cette marque doivent tre reli s la terre afin d assurer un fonctionnement optimal Elle est aussi utilis e pour les l ments de protection contre les interf rences magn tiques les perturbations hautes fr quences radio et contre les surtensions Cette mise terre n est pas une mise terre de s curit pour une protection contre les choques lectriques Indique une alimentation en courant alternatif AC Indique une Alimentation en courant continu DC d riv e d une alimentation alternative Indique la pr sence d un composant sensible aux d charges lectrostatiques ESD Cela signifie qu il faut observer toutes les pr cautions d usage en manipulant ce composant Les termes suivant apparaissent dans ce manuel Note Indique la pr sence d une information que vous devez particuli rement consid rer avant de passer la prochaine instruction or operation Caution Indique une condition ou op ration qui peut entrainer des dommages votre
23. User s Guide The FBA 23 Force Balance Accelerometer Document 302350 September 1997 Trademarks This manual copyright Kinemetrics Inc 1997 All rights reserved Kinemetrics products are covered by U S and foreign patents issued and pending Printed in U S A The trademarks used throughout this manual registered or not are Kinemetrics QuickTalk QuickLook K2 Mt Whitney Etna Etna SI FBA 23 FerriShield IBM PC Microsoft Windows Kinemetrics Inc 222 Vista Avenue Pasadena CA 91107 USA Phone 626 795 2220 W Fax 626 795 0868 E mail services kmi com Website www kinemetrics com Kinemetrics SA Le Tresi 3 1028 Preverenges Switzerland Phone 21 803 2829 M Fax 21 803 2895 E mail kmi sa g bluewin ch Declaration of Conformity WE KINEMETRICS INC 222 VISTA AVENUE PASADENA CA 91107 USA hereby declare that the equipment specified conforms to the following Directives and Standards Product Name Kinemetrics Altus K2 Systems Product Description Strong Motion Recording Systems Model Number s K2 12 channel K2 6 channel K2 4 channel GPS Option Modem Option External Sensors Option FBA 23 FBA 23DH Directives 89 336 EEC 73 23 EEC 93 68 EEC Standards Safety EN 61010 1 EMC EN 55022 Class A EN 50082 2 Supplementary Information Pasadena CA USA 14 August 1997 a S IAN M STANDLEY VICE PRESIDENT ENGINEERING Symbols amp T
24. Zubeh r besteht WARNING Darstellung bei dem die Missachtung in der Regel Verletzungs oder Lebensgefahr besteht FBA 23 Force Balance Accelerometer Safety Spezielle vorbeugende Massnahmen Alle vorbeugende Massnahmen miissen beachtet werden Fiir Ihre pers nliche Sicherheit und um Sch den im FBA 23 zu vermeiden Stromversorgung Die FBA 23 muss entweder mit Strom von einem Accelerograph oder Ihrer eigenen Stromquelle 12 V versorgt werden Sollten Sie planen die FBA 23 mit Strom von einem Recorder zu versorgen verbinden Sie den Recorder mit unserem Kinemetrics Stromladeger t wie es in unserem User Manuel beschrieben ist Um die FBA 23 direkt mit Strom zu versorgen m ssen Sie ein Ladegerat 12 V welches mit allen Sicherheitsbedingunge ausgestattet ist benutzen Optionelles StromversorgungslLadeger t In manchen Fallen wird die FBA 23 eine lange Strecke von dem Recorder entfernt Sein wo es dann m glich sein k nnte dass durch besch digte AC Wiring oder Hohe Erdbewegungen ein Spannungsunterschied besteht Es ist daher unbedingt notwendig dass alle angeschlossenen Instrumente am gleichen Spannungspotential geerdet sind Bitte folgen Sie den vom Hersteller gegebenen Empfehlungen Verkablung und Erdung vom Sensor Wenn das Kabel an einem End geerdet ist kann ein verh ltnism ssig grosser Unterschied in der Voltage bestehen welcher sehr gefahrlich ist Bitte beachten Sie Diese Gefahr und wenn n tig
25. actory adjusted close to the nominal values and are noted in the calibration sheet of each sensor In order to be more precise you must take into account poles based on values from the calibration sheet rather than the nominal values Sensors with different absolute sensitivity have the same second order poles However the low pass filter in the post amplifier stage depends on the sensor s full scale sensitivity Poles pertaining to mechanical elements and the internal low pass filter in the trans conductance amplifier which are insignificant in most cases also depend on the full scale sensitivity of the sensors If you wish you can determine the modification of the TF due to mechanical elements and the internal low pass filter An identification program like UNICAL based on the inversion of step or impulse response or MatLab functions can be used for this purpose FBA 23 Force Balance Accelerometer 5 3 Theoretical Second Order Tranfer Function Absolute Gain The theoretical second order transfer function of the FBA 23 is E e OUT n Ex s 2 6 0 s where 0 is the natural frequency S is the Laplaceoperator 4 is therelativedamping Eour is the output voltage Epc is thesensitivity This can be solved as a quadratic to find the two complex poles p 0 j 0 41 6 P O JMD 1 2 These equations can then be used with the calibration constants below or those taken from the unit s calibration data to calcula
26. age reading is more than 25 mV or less than 25 mV then the longitudinal L accelerometer offset requires zero adjustment To adjust the longitudinal accelerometer 1 Remove the L access screw then insert a small flat bladed screwdriver into the screw hole and into the slotted end of the longitudinal accelerometer s pivot Caution This adjustment is very small not more than 1 Do not turn the accelerometer s pivot more than 2 The unit has a mechanical stop that prevents over rotation of the pivot Do not try to force the adjustment beyond this stop You will break the unit 2 Apply gentle pressure with the screwdriver to the pivot until the voltage is between 25 mV and 25 mV If the reading is too positive turn the pivot clockwise but not more than 1 If the reading is too negative turn the pivot counterclockwise but not more than 1 3 4 Kinemetrics Operating Basics 3 Once the voltage reading is in the proper range remove the screwdriver and replace the access screw To check the zero adjustment of the vertical accelerometer use one of the methods described above to measure the sensor s zero output voltage If the voltage reading is more than 25 mV or less than 25 mV then the vertical V accelerometer offset requires zero adjustment To adjust the vertical accelerometer 1 Remove the V access screw then insert a small flat bladed screwdriver into the screw hole and into the slotted end of the
27. age to the FBA 23 Power Source The FBA 23 must be supplied with power either from an recorder or from a customer supplied 12V power supply If you plan to power the FBA from a recorder connect the recorder to a power supply charger supplied by Kinemetrics as described in each recorder s user manual To supply power directly to the FBA you need a low noise regulated 12V power supply that is safely grounded and meets all applicable local regulations User Supplied PowerlCharging System If you supply your own power charging system be sure that the system provides the correct voltage and current required by the FBA 23 under all operating conditions You are responsible for the safety of your charging system If you get power from the mains supply be sure you have supplied adequate grounding for all the equipment If you supply your own batteries follow the manufacturer s safety recommendations Sensor Grounding and Cabling In some cases the FBA 23 will be a long distance from the recorder In 24 these installations it is possible due either to faulty AC wiring or extremely high earth return currents for a high potential difference to exist between the grounds at the two locations When the cable is grounded at one end a potentially lethal voltage can exist between the other end of the cable and ground Consider this danger during installation and get help from a qualified electrician if this danger exists Do Not Operate
28. apply gentle pressure to the pivot until the voltage is between 25 mV and 25 mV If the reading is too positive turn the pivot clockwise but not more than 1 If the reading is too negative turn the pivot counterclockwise but not more than 1 3 Once the voltage reading is in the proper range remove the screwdriver and replace the access screw FBA 23 Force Balance Accelerometer 3 5 The FBA is now correctly zero adjusted If you removed the cover to perform these adjustments follow the instructions to replace it If you used a break out cable remove it and reconnect the actual sensor cable Performing a Functional Test on an FBA with an Altus Recorder An Altus recorder generates the exact signals required to perform a functional test sequence on the FBA 23 If you are not using a Kinemetrics recorder you should refer to Chapter 6 for information on how to simulate a functional test Altus recorders have two types of functional tests The standard functional test runs at the current sampling rate of the instrument It fully tests the instrument in its operating configuration However the sensor s response is combined with the response of the digital filter and this can make quantitative interpretation of the sensor response difficult especially for an FBA with a high natural frequency To allow the sensor response to be determined a Sensor Response Test SRT function is also available The SRT performs the functional test
29. ational If the recorder does not provide this connect the line to the 12V supply The Undamp line should be connected to circuit common if it is not used To produce the Kinemetrics functional test sequence the data logger needs to control both the Ca and Undamp line If the data logger cannot perform these functions a simple test box can be built to simulate the desired calibration sequence A suggested sequence is as follows 1 Hold Cal at 2 5V for 2 seconds undamp unconnected 2 Change Cal to 2 5V for 2 seconds undamp unconnected 3 Change Cal back to lt 2 5V and at the same time connect undamp to 12V and leave for 1 5 seconds 4 Disconnect undamp and leave Cal at lt 2 5V for 0 5 seconds 5 Change Cal to 2 5V for 2 seconds undamp unconnected 6 Finally hold Cal at lt 2 5V for 2 seconds undamp unconnected This will produce the classic Kinemetrics two pulse waveform described in Chapter 3 Caution Failure to connect the Cal line to a negative potential can result in severely degraded noise performance When using the FBA 23 with non Kinemetrics digitizers it is essential that the ground connections be carefully planned to prevent the occurrence of ground loops This is especially important when using a PC based data acquisition system The signal returns should be connected to the negative input of the analog front end s differential or instrumentation amplifier and not to circuit common
30. der cable end with rope and cellophane removed N Figure 2 8 illustrates the steps described below 1 Unwrap the foil shield from each of the twisted wire pairs 2 Separate out the non insulated stranded drain wires and pull them toward the cable center 3 Rewrap the foil shields around the twisted pairs 4 Take the six pieces of 3 8 x 1 foil tape One at a time take each and beginning as close as possible to the pulled out drain wires and the cable s outer jacket wrap it tightly around a foil shield Make sure your wrapping flows in the same spiraling direction as the shield you are wrapping it around Wrap all six foil shields identically 5 From each twisted pair remove the excess shield above that shield s foil tape as shown by the twisted wire pair to the left in Figure 2 8 FBA 23 Force Balance Accelerometer 2 13 Figure 2 8 Detail of the foil shields drain wires and foil tape 6 Bring all the drain wires together and twist together in the center of the cable 7 Break out one of the drain wires from the group at 3 8 toward the blue and black twisted pair as shown in the center of Figure 2 9 8 At the 3 8 break out point quickly but carefully apply solder to the clustered drain wires Note In the blue and black twisted pair strip off 1 16 of the black insulation just above the foil tape and solder tinning This will leave 1 16 of exposed wire in the black lead 2 14 Installation
31. der end mating connector assembly eoo ut rated eh te nn 10 Figure 2 5 Preparing 3 8 wide foil tape from 1 foil tape 11 Figure 2 6 Recorder cable end with outer PVC jacket TEMO ceti A em e d e e opa Redes 12 Figure 2 7 Recorder cable end with rope and cellophane TOI VO as oet Des o toute E RAR ENE 13 Figure 2 8 Detail of the foil shields drain wires and foil TADS etu s ee SG 14 Figure 2 9 The drain wires twisted together 15 Figure 2 10 Drain wire to black wire Connection 15 Figure 2 11 Outer foil tape and drain wire shrink tubing 16 Figure 2 12 Schematic of external FBA 23 cable to both mating Connectors aS 16 Figure 2 13 The foil tape and the stripped and tinned wires 17 Figure 2 14 Wrapping the connection with PVC tape 17 Figure 2 15 Wrapping foil tape around the outside of the COMEN uoce en Tu opo teo idea Nee aa 18 Figure 2 16 Slipping the Shrink n Shield tubing into place 18 Figure 2 17 The Shrink n Shield tubing in correct position after Someta aono eer ee e e NP eS 18 Figure 2 18 Completed assembly of the recorder end of Cable 540350 an ee de 18 Figure 2 19 Parts for the FBA 23 end mating connector A ey d ad 21 Figure 2 20 Preparing 3 8 wide foil tape from 1 foil tape 22 Figure 2 21 The connection wrapped with PVC tape 23 Figure 2 22 Wrap
32. e disadvantage that you may allow dust or debris into the sensor that could damage the unit Thus you should only use this method in a reasonably clean environment such as inside a building To use this method proceed as follows 1 Remove the top of the FBA 23 by unscrewing the 12 small screws using a flat bladed screwdriver Remove the lid taking care not to disturb the sealing gasket 2 With the connector facing you first adjust the L sensor This is the sensor on the upper left Connect the positive lead of the DVM to the output terminal labeled F on the printed wiring board silkscreen and the negative lead to the common connection labeled G See Figure 3 2 Follow the instructions in the section below for zeroing the L sensor 3 Next adjust the V sensor at the front of the unit next to the connector Leave the negative lead of the DVM connected to the L sensor it is very difficult to get to pin G on the vertical sensor Connect the positive lead to the F terminal of the vertical sensor This is the first pin to the right of the adjustment pivot and has a white wire connected to it Follow the instructions in the next section for zeroing the V sensor 4 Next adjust the T sensor at the back right of the unit next to the connector Connect the positive lead of the DVM to the F terminal of the sensor Connect the negative lead to the common connection labeled G on the circuit board Follow the
33. e 2 12 carefully Caution Do not proceed to the shield to shell testing until all the pairs of insulated conductors have passed the four test steps above Once you ve completed testing all the pairs of insulated conductors test the connection of the wire shields to the recorder end of the connector shell 1 At the FBA 23 end take the white black pair of wires and use a test lead jumper to connect the white wire to the exposed drain wires 2 When that is done the DVM at the recorder end should show that pin L is connected to the recorder end connector shell and to pin U The DVM should measure lt 1 5Q per 100 of cable If so remove the test jumper at the FBA 23 end of the cable 3 At the recorder end disconnect the DVM lead from connector pin L and confirm that the connector shell and pin U are infinite with respect to all other connector pins 4 With the preliminary cable testing completed disconnect all test equipment 5 At the FBA 23 end gather the 2 of wires shields cord etc that you stripped back cut off these exposed elements and discard them Caution Do not connect the recorder connector to the recorder until you have installed the FBA 23 connector and have completed the final testing described at the end of the cable assembly process If all the recorder end connections passed the above test proceed to the next section Initial Assembly of the FBA 23 End Having already assembled the connect
34. e back of the grommet and the foil tape also shown in Figure 2 21 Figure 2 21 The connection wrapped with PVC tape Now between the back of the grommet and the end of the cable outer jacket tightly wrap 1 x 3 foil tape around the cable as shown in Figure 2 22 Note The 1 wide foil tape must be in tight contact with the 3 8 wide foil tape Figure 2 22 Wrapping foil tape around the outside of the connection Then slide the braid shield Thermofit tubing connector back shell and the rubber boot forward as shown in Figure 2 23 Figure 2 23 Braid shield shrink tubing connector shell and boot FBA 23 Force Balance Accelerometer 2 23 Slide the braid up over the plastic grommet ring Then position it carefully so it covers up to but does not overlap the connector threads as shown in Figure 2 24 Press the braid into place around the back of the grommet then as shown in Figure 2 22 slide the Thermofit tubing over the braid and up to the back of the braid covered grommet Figure 2 24 Braid shield and shrink tubing in position and shrunk Now using even heat shrink the tubing until it fits tightly in place over the braid and foil tape as shown in Figure 2 24 and begin the final assembly process 1 Slide the boot and connector shell forward and screw tighten the connector shell onto the connector head 2 Check the resistance from the connector shell to the connector shell at the oth
35. en mounted is pointed to true north which is the normal orientation used for free field strong motion studies Note If you use a compass to determine true north south axis be sure to correct for the difference between magnetic north the direction indicated by the compass and true north Mounting the FBA 23 If you do not wish to use the Red Head anchor stud KMI P N 869002 supplied with the FBA 23 you need to provide an anchor in the mounting surface that can accept the 1 4 20 bolt supplied with the FBA 23 To mount the FBA 23 first install the mounting anchor by following the manufacturer s instructions Refer to Figure 2 2 then center the FBA 23 over the mounting anchor with the orientation arrow aligned approximately to true north and insert the 4 FBA 23 Force Balance Accelerometer 2 5 bolt with the supplied washer through the FBA 23 anchor hole until it engages in the anchor Tighten loosely and follow the instructions on leveling the unit WARNING When using power tools and or a hammer be very careful and always wear safety glasses to protect your eyes Using Kinemetrics Anchor There are three ways to drill a hole in concrete for the heavy duty anchor supplied with the FBA 23 One way is to hold the self drilling anchor itself in the drill chuck and use the anchor to drill the hole to a depth of 17 174 If no drill is available the hole can be drilled manually using the manual anchor drill option available
36. er end of the cable The resistance will vary depending on cable length but should be very low lt 0 3 Q 100 3 Place the two halves of the cable clamp in place then tighten its screws Figure 2 25 Completed assembly of the FBA 23 end of cable 840356 Testing Connector Assembly 2 You should also do a buzzing out test on this end of the cable to make sure you connected the proper wires to the proper solder cups per the 2 24 Installation Basics schematic in Figure 2 12 and that no wires have gotten shorted in the assembly process To do this test use the pins in the assembled connector at the recorder end as response conductors Set the DVM to measure resistance in the range of several hundred ohms Then 1 At the FBA 23 end connect one DVM lead to connector pin A top left in Figure 2 12 Then with the other DVM lead check that all other pins in that connector are infinite with respect to pinA 2 At the recorder end of the cable have another technician take the connector and use a test lead jumper to connect connector pin L to connector pin M 3 Now the DVM at the FBA 23 end should show that pin A is connected to pin B the DVM should measure lt 2 5 Q per 100 of cable If it does have the other technician remove the test jumper at the recorder end 4 Disconnect the DVM lead from connector pin A and with the other DVM lead still connected to pin B confirm that it is infinite with respect to a
37. erms Safety These symbols may appear on Kinemetrics equipment or in this manual Signifies pay attention When you see this symbol on the instrument refer to the similarly marked relevant part of this manual Before attempting any service on the instrument you must read the relevant parts of this manual If you see this symbol pay careful attention Signifies a low noise earth ground The noted item should be grounded to ensure low noise operation and also to serve as a ground return for EMI RFI and transients Such a ground does not work as a safety ground for protection against electrical shock Signifies an Alternating Current AC power line Signifies a Direct Current DC power line derived from an AC power line Signifies an Electrostatic Sensitive Device ESD meaning that when handling the marked equipment you should observe all standard precautions for handling such devices These safety related terms appear in this manual Note statements identify information that you should consider before moving to the next instruction or choice Caution statements identify conditions or practices that could result in damage to the equipment the software or other property WARNING statements identify conditions or practices that could result in personal injury or loss of life FBA 23 Force Balance Accelerometer Safety Specific Precautions Follow the precautions below to ensure your personal safety and prevent dam
38. ertical channel results in a negative output voltage E Longitudinal Transverse 5 6 Reference Electrical Interface Figure 5 2 Input connections L Signal Output Output Signal output from Longitudinal Accelerometer L Signal Common Output Signal common for Longitudinal Accelerometer L Signal Shield Case Shield connection for Longitudinal Accelerometer V Signal Common Output Signal common for Vertical Accelerometer V Signal Shield Case Shield connection for Vertical Accelerometer T Signal Output Output Signal output from Transverse Accelerometer T Signal Common Output Signal common for Transverse Accelerometer T Signal Shield Case Shield connection for Transverse Accelerometer Cal Input Calibration input to provide step voltage When connecting to non Kinemetrics data acquisition equipment must be held below 2 5V when not active Should swing to 2 5V to produce Step in Functional Test L Undamp Input Undamp signal input to FBA 23 When connecting to non Kinemetrics data acquisition equipment should be held at high impedance or 0V when not active Should be held at 12V to undamp the sensors Power Common Input 12 VDC power input Input 12 VDC power input Case Ground Case Sensor Case Ground Ground J N C N C No Connection H N C N C No Connection V Signal Output Output Signal output from Vertical Accelerometer me FBA 23 Force Balance Accelerometer 5 7 6 Advanced Instal
39. from Kinemetrics as P N 100208 The third way is to use a hammer drill with a 2 masonry bit and drill a hole 1 114 deep To manually drill the hole 1 Place the stud in the desired location and insert the long rod into the top hole of the holder so that you can turn it 2 Hitthe top of the holder with the hammer while turning the holder The serrated teeth on the bottom of the stud will start drilling into the concrete 3 Continue hammering and twisting until the anchor is in the concrete to just under the cone shaped head This takes patience 4 Now pull the anchor out of the hole and clean out the debris To install the anchor Once the hole has been drilled the anchor needs to be installed Proceed as follows 1 Insert the narrow end of the expanding cone shaped piece in the bottom of the anchor 2 Insert the anchor into the hole Leave the Kinemetrics holder attached if you have it 3 Hammer on top of the Kinemetrics holder or the anchor to expand the cone and firmly secure the anchor 4 Finally break the cone from the top of the anchor by hitting either the holder or the cone sharply on the side with the hammer Note To re use the Kinemetrics holder insert the wedge shaped end into the lower hole in the holder and use it to eject the cone Installation Basics To anchor the FBA 23 Refer to Figure 2 2 as you anchor the FBA 23 to the ground 1 Center the FBA 23 over the mounting hole Be sure the
40. he listed order top to bottom If you are not sure which pieces of the connector to use see Figures 2 16 2 17 and 2 18 to help identify the right parts Table 2 2 Part order recorder cable end Part Name KMI P N Thermofit tubing 851186 Connector back shell part of P N 851119 Shrink N Shield tubing 850839 Connector s plastic grommet ring part of P N 851119 3 Discard the connector strain relief boot a part of P N 851119 Identical Assembly Procedures From this point up to the next section the assembly procedures and illustrations are exactly the same for both ends of the cable Once you have attached the recorder end go to the Initial Assembly of the FBA 23 End section that contains procedures unique to the FBA 23 end Then return here to repeat the Identical Assembly Procedures for the FBA 23 end Finally follow the procedures in Final Assembly of the FBA 23 End 1 Using a utility knife strip and remove 2 of the cable s outer PVC jacket 2 Fold back the cellophane and white string covering the shielded wires 3 Spread the shielded pairs of wire outward from the center rope cord as shown in Figure 2 6 Figure 2 6 Recorder cable end with outer PVC jacket removed Installation Basics 4 Cut off and discard the center rope cellophane and white string Cut them back as near as possible to the new end of the cable outer jacket as shown in Figure 2 7 Figure 2 7 Recor
41. ibes the necessary supplies and generalized steps for assembling a CE quality FBA 23 cable using Kinemetrics P N 700045 cable The assembly techniques required are in general the same as those in the Cable Assembly section in Chapter 2 of this manual Please read through those directions carefully to familiarize yourself with the process before beginning the instructions outlined below FBA 23 Force Balance Accelerometer 6 1 Figure 6 1 Drawing 109712 xx K2 external FBA 23 cable assembly Il CE Cable Assembly Table 6 1 Required parts for the Altus recorder mating connector assembly Part Name KMI P N Commercial P N Description Mating connector 851119 851 06EC14 19PN50 1 connector Foil tape 880700 1183 1 wide 3 pieces 1 x 2 1 2 ea Termofit tubing 851186 DWP 125 3 4 black 1 piece 4 1 2 ea Braid 20 AWG 1 wide 840458 1235 1 piece 3 1 4 ea Wire 18 AWG blk 840508 UL1429 18 1930 0 3 pieces 3 ea Shrink tubing 1 4 850839 FIT 221 1 4 3 pieces 1 2 ea Shrink tubing 1 8 850818 FIT 221 1 8 2 pieces1 2 ea Teflon tubing 840392 TFT 200 18 I piece 3 ea 6 2 Advanced Installation Topics Initial Assembly of the Altus Recorder End FBA 23 Force Balance Accelerometer 4 10 11 12 13 14 15 16 17 18 19 20
42. il ALTUS QuickT alk i is ER Kinemetrics QL Figure 3 5 Sensor response test of an FBA 23 Kinemetrics QLWIN Version 2 40d 4 18 97 File ZoomSize Pan Chan Screen Header Help Cond 10 72 1 ZCond 10 42 1 4 2263076Vmax 0663880Vmid 0935316Vmin 3198392Vpp 5 2171934Vmax 0571734Vmid 1028466Vmin 3200400Vpp 6 2388454Vmax 0828448Vmid 0731558Vmin 3120012Vpp Lotus cc Mail Mail 3 8 Kinemetrics a Operating Basics Figure 3 6 Sensor response test ringdown inemetrics QLWIN Version 2 40d 4 18 97 File ZoomSize Pan Chan Screen Header Help C ALTUS DWOOS EVT SRT 08 26 59 000 Cond 10 72 1 ZCond 10 42 1 EZ 4 2263076Vmax 0663880Vmid 0935316Vmin 3198392Vpp 5 2171934Vmax 0571734Vmid 1028466Vmin 3200400Vpp 6 2388454Vmax 0828448Vmid 0731558Vmin 3120012Vpp A Start 2 Lotus cc Mail Mail eO ALTUS QuickTak BY Microsoft Word dw Figure 3 7 Component of a functional test Typical functional test amplitude mn 10 full scale Undamped response Damped response measured here 1 cycle of natural frequency I w 100 Overshoot B i I 0 5 1 5 Second Ringdown FBA 23 Force Balance Accelerometer a 3 9 4 Maintenance Recommended Maintenance The FBA 23 is designed for many years of una
43. in Explosive Atmosphere The FBA 23 provides no explosive protection from static discharges or arcing components Do not operate the equipment in an atmosphere of explosive gases FBA 23 Force Balance Accelerometer Safety Sicherheit Symbole amp Begriffe Diese Symbole k nnen auf Kinemetrics Ger te oder in diesen Manuel erscheinen Bedeutet Achtung Wenn sie dieses Symbol auf ein Gerat sehen muss den JIN gleich markierten Teil dieses Manuels beachet werden Bevor irgend eine Unterhaltsarbeit angefangen wird muss dieser Teil des Manuels gelesen werden Wenn Sie dieses Symbol sehen bitte besondere Achtung geben noise operation zu versichern und dann auch als Erdung f r EMI FRI und Transienten und solch eine Erdung wird nicht als Sicherheit gegen elektrischen Schock dienen Bedeutet Erdung Das erwaente Teil sollte geerdet werden um eine low 2x Bedeutet Wechselstromzufuhr AC mit Elektroschock Gefahr Bedeutet Gleichstromzufuhr von AC Versorgung herkommend a Bedeutet Elektrostatisch Sensibeles Element ESD f r dessen Handhabung Ka alle vorbeugende Vorsichtsmassnahmen genommen werden m ssen Folgende Darstellungen werden in diesen Manuel erscheinen Note Darstellung welche Informationen Sie erhalten die besonders beachtet werden m ssen bevor sie zum n chsten Schritt gehen Caution Darstellung bei dem die Missachtung in der Regel Gefahr fiir Defekte und St rungen im Ger t Programm oder
44. ing slide the grommet and plastic grommet ring forward and up against the connector head shown on the right side of Figure 2 14 3 Then apply two turns of insulating PVC tape between the back of the grommet and the foil tape also shown in Figure 2 14 Figure 2 14 Wrapping the connection with PVC tape Now between the back of grommet and end of the cable outer jacket tightly wrap 1 x 3 foil tape around the cable as shown in Figure 2 15 below Note The foil tape must be in tight contact with the 3 8 wide foil tape FBA 23 Force Balance Accelerometer 2 17 Figure 2 15 Wrapping foil tape around the outside of the connection SS Slide the Shrink N Shield tubing forward as shown in Figure 2 16 then up over the plastic grommet ring Figure 2 16 Slipping the Shrink n Shield tubing into place Now carefully place the tubing so its cloth shield is up against but not covering over the connector threads as shown in Figure 2 17 below Figure 2 17 The Shrink n Shield tubing in correct position after shrinking Now using even heat shrink the tubing until it is tightly in place over the foil tape as shown in Figure 2 17 and begin the final assembly process 1 Slide the connector shell forward and screw tighten it onto the connector head 2 Check the resistance from the connector shell to the shields at the other end of the cable The resistance will vary depending on cable length but should be
45. lation Topics This chapter contains information on various advanced installation topics that may apply to your installation Kinemetrics Services Group can provide additional information on these topics CE Compliant Installations Long Cables The FBA 23 has been tested with an Altus K2 and found to comply with the emissions and immunity requirements of the European Union For the installation to meet these requirements the cabling construction must follow the recommendations given in Chapter 3 and the FerriShields supplied with the CE certified recorder must be attached to each end of the cable Failure to follow these instructions could result in the system being in violation of the EU directives The FBA 23 can be used with the normal Kinemetrics cable P N 840356 or Belden 9874 for distances up to 1000 feet with a variety of instruments If the FBA 23 is used with an Altus accelerograph this distance can be extended up to 2000 feet In the case of cable runs of this length we recommend installation in a grounded metal conduit If cable is not installed in its own conduit and maximum resolution is required it should not be run alongside cables carrying heavy AC or transient currents For longer runs Kinemetrics P N 700045 cable is recommended and this can be used for distances of up to 3000 feet Brief assembly instructions for this cable are provided below Cable Assembly with P N 700045 2 The following section descr
46. lectrostatic discharge ESD hazard to equipment Wear a grounded wrist strap with impedance of approximately 1 M Q when handling the FBA 23 circuit boards to protect components from damage Troubleshooting and Repair If your FBA 23 does not appear to be working we suggest you first check that the cabling and power supply are correct If the problem persists we recommend you return the unit to Kinemetrics for repair and re calibration FBA 23 Force Balance Accelerometer 4 11 Modification of Range or Natural Frequency Calibration The range and natural frequency of the FBA 23 are factory set and can only be changed at the factory Please contact Kinemetrics Services Group for the current pricing of these services The FBA 23 is very reliable and maintains its calibration in the field for many years A functional test will provide a good indication of whether the sensor is working properly A further quick check of the calibration can be performed in the field by simply tilting the sensor 90 and 90 in each axis By tilting the sensor an acceleration of 1g can be measured Kinemetrics can supply a tilt table and training in order to perform more accurate calibrations verifications in the field Kinemetrics can also provide on site or factory calibrations traceable to national standards Maintenance Theory of Operation 5 Reference The FBA 23 consists of three orthogonally mounted force balance accelerometers FBAs
47. ll other connector pins You have now buzzed out the top two connections A and B shown top left in Figure 2 12 for the two wires in the white black pair Now repeat Step 1 through Step 4 but test connector pins C and D and the two wires in the green black pair Follow Steps 1 through 4 for each pair of connector pins and wire pairs in the remaining five pairs of wires and 10 connections shown in Figure 2 12 Carefully check that all other pins in the connector are infinite with respect to the connector pin you are testing that the two pins in each pair can be linked without problems and that the pin you are testing is infinite with respect to all other connector pins As you test follow the left end of Figure 2 12 carefully Note Do not proceed to the shield to shell testing until all the pairs of insulated conductors have passed the four test steps above To test the connection of the wire shields to the FBA 23 end connector shell 1 At the recorder end have another technician take the recorder connector and use a test lead jumper to connect pin L to the recorder end connector shell 2 The DVM at the FBA 23 end should show that pin A is now connected to the K2 end connector shell and to pin T The DVM should measure 1 5 O per 100 of cable If it does have the technician remove the test Jumper at the recorder end FBA 23 Force Balance Accelerometer 2 25 3 Disconnect the DVM lead from connector pin A and confirm that yo
48. mentation Si vous utilisez le courant du r seau d alimentation principal vous devez vous assurez d installer les mises a la terre ad quates pour tout votre equipement Si vous utilisez vos batteries vous devez vous r f rer aux recommendations fournis par le fournisseurs 1 Mise la terre et connection du capteur Dans certain cas le capteur FBA 23 est install distance de l enregistreur Dans ces installations il est possible soit a cause d une connection d fectueuse au syst me d alimentation principale o d un fort courant de retour la terre pour une difference de potentiel qui existe entre la mise la terre aux deux locations Quand le cable est mise la terre d un cot une tension potentiellement fatale peut exister entre l autre cot du cable et la terre Considerez ce danger pendant l installation et demandez l aide d un electricien si ce danger existe Ne Pas Utiliser en Atmosphere Explosif Le FBA 23 ne comprend pas de protection contre les explosions dues aux d charges statiques ou aux composants pouvant provoquer des arcs Ne pas utiliser ces composants en pr sence de gaz explosifs FBA 23 Force Balance Accelerometer Safety Contents 1 Getting Started Inspecting the FRA 3 ue e ea tele ER 1 2 Installation Basics Requirements for Installation aus 3 Required Tools se endis iii 3 Required Supplies asien aaa 4 Required Equipment 1 5 eet eek 4 Mounting and Orienting the FBA 23
49. n into place 43 Install the two halves of the connector cable clamp 44 Using the schematic portion of Drawing 109712 as a guide test the cable following the same concepts outlined in Testing Connector Assembly 2 in Chapter 2 The FBA 23 end of the assembly is now completed User Supplied Cable If you are using your own cable you must be sure that is has sufficient conductors of the required wire gauge for your installation and that it provides adequate shielding to maintain the noise performance of the FBA 23 The conductors used for the signals and the control signals Cal and Undamp carry little current The table below shows the resistance and calculated voltage drop for different lengths of cables The length of cable run determines the required cable size The figures below are for an Altus recorder Substitute the worst case values for your power supply if you are using a non Kinemetrics recorder The standard Kinemetrics cable will work up to 2000 feet with an Altus recorder The thicker Kinemetrics 700045 cable can be used for distances of up to 3000 feet FBA 23 Force Balance Accelerometer 6 5 Grounding 6 6 Table 6 3 FBA 23 cabling voltage drop calculator Sensor Type FBA 23 2g Sensor Minimum Operating Voltage 10 5 V Sensor Active Current 15 mA Minimum Supply Voltage 11 1 V Allowed Cable Voltage Drop 0 6 V One Way Allowed Cable Drop 0 3 V Allowable One Wa
50. ncy and damping could easily be measured Figure 3 8 identifies the various features of the functional test discussed in this section Kinemetrics Operating Basics Table 3 1 Overshoot Rates Damping Overshoot 0 60 93 0 61 8 9 0 62 8 35 0 63 7 8 0 64 pr 0 65 6 8 0 66 6 3 0 67 5 9 0 68 5 4 0 69 5 0 0 70 4 6 i Kinemetrics QLWIN Version 2 40d 4 18 97 Figure 3 3 QuickLook display of an FT at 100 sps Fie ZoomSize Pan Chan Screen Header Help C YALTUSYDWOO3 EVT FT 9 16 1997 259 08 04 38 000 Display 6 6 EZ 31 0000 E 31 0000 AD Rl Dl VO A Start Lotus cc Mail Mail EJ File Manager sS ALTUS QuickTalk BY Microsoft Word dw 2274037Vmax 1079297Vnid 0115442Vmin 2389479Vpp 5 2159524Vnax 0958058Vnid 0243408Vmin 2402932Vpp 6 2413339Vmax 1215667Vmid 0017995Vmin 2395344Vpp FBA 23 Force Balance Accelerometer Figure 3 4 QuickLook display of an FT at 200 sps Kinemetrics QLWIN Version 2 40d 4 18 97 File ZoomSize Pan Chan Screen Header Help Display 6 6 AO R1 Dl VO Cond 9 19 1 ZCond 8 93 1 BZ EZ 30 0000 E 30 0000 4 2274222Vmax 686008Vnid 0902206Vmin 3176428Vpp 5 2186162Vmax 0619492Vmid 0947178Vnin 3133339Vpp 6 2406794Vmax 0911939Vmid 0582916Vmin 2989710Vpp Rel to Ch 4 Lotus cc Mail Ma
51. ntain the true north orientation in a free field installation or the structure axis orientation in a structure This section provides instructions for assembling an FBA 23 to Altus recorder cable based on a Belden cable KMI P N 840356 If you are using Kinemetrics P N 700045 cable refer to Chapter 6 for assembly instructions EMI EMC regulations these instructions must be followed exactly The ce To be sure the installation meets the requirements of the European instructions assume the cable has already been pulled and routed through appropriate conduit If possible Kinemetrics recommends that cables be routed in grounded metal conduit Installation Basics Z TT NSULATING PVC TAPE NJM 35 TYPE I FBA 23 Force Balance Accelerometer Figure 2 3 FBA 23 to Altus recorder cable REFERENC S T QTY DESCRIPTION REFERENCE 3 REF CABLE 6 TWISTED PAIRS 20 AWG 1 CONNECTOR MATING 1 CONN 17 CONTACT PIN 1 RUBBER BOOT 12 TAPE FOIL 3 8 WIDE ONG 2 TAPE FOIL 3 8 WIDE 3 LONG 2 TAPE FOIL 1 WIDE 3 LONG 1 SHRINK TUBING 3 4 DIA N SHIELD 3 LONG SHRINK TUBING 1 4 DIA X 1 2 LG BLACK CUT IN HALF TUBING HEAT SHRINK ADHESIVE LINED 3 4 LONG TUBING HEAT SHRINK ADHESIVE LINED 2 LONG 12 840458 BRAID 20 AWG 1 WIDE 2 LONG FBA 23 gt i DRAIN WIRES REF u B DRAIN WIRES E R S
52. ommet Slide the braid 20 forward until it covers the back end of the connector grommet and foil tape Slide the connector back shell forward and tighten into place The braid shield should just be caught inside the connector back shell when correctly installed Mold the braid around the foil tape wrapped cable Slide the Thermofit tubing forward over the braid and shrink Install the two halves of the connector cable clamp 6 3 6 4 25 Using the schematic portion of Drawing 109712 as a guide test the cable following the same concepts outlined in Testing Connector Assembly 1 in Chapter 2 The Altus end of the assembly is now completed Initial Assembly of the FBA 23 End Table 6 2 Required parts for the FBA 23 end mating connector assembly Part Name KMI P N Commercial P N Description Mating connector 850407 MS3106F 20 29P I connector Extension tube 101189 20 Foil tape 880700 1183 1 wide 3 pieces 1 x 2 1 2 Termofit tubing 851186 DWP 125 3 4 black 1 piece 2 2 Braid 20 AWG 1 wide 840458 1235 1 piece 3 Shrink tubing 1 4 850839 FIT 221 1 4 3 pieces 1 2 Shrink tubing 1 8 850818 FIT 221 1 8 2 pieces 1 2 Teflon tubing 840392 TFT 200 18 1 piece 2 26 Slide the Thermofit tubing connector back shell and braid over the outer jacket of the cable 27 Remove 2 3 4 of the outer jacket from the end of the cable 28 Remove 2 3 8 of the
53. onnected to a good earth ground Cover the braid and the capacitor with shrink tubing Advanced Installation Topics Note This technique provides a single point ground for low frequency signals at the recorder end of the cable but at high frequencies the capacitor conducts providing an AC ground for EMI RFI signals WARNING Potential lethal voltages In these configurations potentially lethal voltages can exist between the conductors on the cable or the exposed metal parts of the FBA 23 These occur due to differences in ground potential between the location of the K2 and the location of the FBA 23 Faulty electrical wiring returning large currents to ground normally causes these differences t is the user s responsibility to ensure that hazardous conditions are not created and that all local electrical safety regulations are observed Use with Non Kinemetrics Data Loggers Power Supply ZN Output Voltage If you are using the FBA 23 with a non Kinemetrics data logger you must match the power calibration and output of the FBA 23 with that of the recorder Kinemetrics Services group can provide help with this and can also supply conversion boxes to interface to some commonly used seismic instrumentation The FBA 23 requires a well regulated low noise 12V 5 supply that can supply 25 mA from each rail In quiescent conditions the power required by the unit will be about 10 mA During an event additional current is
54. or on the recorder end of the cable you should now have only those items necessary for assembling the FBA 23 end of the cable left in the assembly kit To make sure select the parts listed in Table 2 3 and illustrated left to right in Figure 2 19 To install FBA 23 mating connector P N 850407 on the FBA 23 end of the 840356 cable you will require Installation Basics Table 2 3 Parts required for the FBA 23 end mating connector assembly Part Name KMI P N Commercial P N Description of Item s Mating Connector 850407 MS3106F 20 29P 1 connector Rubber Boot 850034 MS39056 6 1 boot Foil Tape 880699 1183 3 8 wide 6 pieces 3 8 x 1 Foil Tape 880699 1183 3 8 wide 1 piece 3 8 x 3 Foil Tape 880700 1183 1 wide piece 1 x 3 Shrink Tubing 850839 FIT 221 1 4 1 piece cut 1 4 long Thermofit Tubing 851186 DWP 125 3 4 black 1 piece 2 long Braid 220 AWG 1 wide 840458 1235 1 piece 2 long Figure 2 19 Parts for the FBA 23 end mating connector assembly Note foil In place of the 3 8 foil tape you may have received two 1 wide If your kit contains this substitution then do the following 1 Divide one of the 1 x 3 pieces into thirds the long way as shown in the middle grouping in Figure 2 20 so you have three 3 long pieces 2 Then divide two of the approx 3 8 wide strips into 1 long segments as shown in the bottom grouping in Figure 2 20 When finished yo
55. ping foil tape around the outside of the CONNECTION se nan rt uen ue 23 Figure 2 23 Braid shield shrink tubing connector shell and Ho sad 23 Figure 2 24 Braid shield and shrink tubing in position and JG EEE pr 24 Figure 2 25 Completed assembly of the FBA 23 end of cable 540956 Keen 24 F re 3 17 E 5 mes host AEG 1 Figure 3 2 One of three accelerometers inside the FBA 23 2 Figure 3 3 QuickLook display of an FT at 100 sps 7 Figure 3 4 QuickLook display of an FT at 200 sps 8 Figure 3 5 Sensor response test of an FBA 23 sss 8 Figure 3 6 Sensor response test ringdown cccccsseesseeeteeeeeeeeees 9 Figure 3 7 Component of a functional test 9 Figure 5 1 Simplified block diagram of an accelerometer inside the FBA 23 unicidad cia 1 Figure 5 2 Input connections ran did 7 Figure 6 1 Drawing 109712 xx K2 external FBA 23 cable 2556 Mb ii il 2 FBA 23 Force Balance Accelerometer Safety 1 Getting Started This chapter provides an overview of the FBA 23 and the considerations and tools required to install it Please read this chapter before starting the installation The FBA 23 is a triaxial accelerometer optimized for recording signals from earthquakes Inside the waterproof cast aluminum housing are three low noise force balance accelerometers mounted orthogonally to each other Each accelerometer produces an analog voltage ou
56. ransverse zero offset can be adjusted m Three adjustable leveling feet m A vertical hole for the anchor bolt A connector for the analog output voltages from the accelerometers and for supplying power and control signals to the FBA Figure 3 2 One of three accelerometers inside the FBA 23 If you are using the FBA 23 with a Kinemetrics Altus recorder the recorder will supply the necessary 12V power from the isolated DC DC converters in the unit If you are using another recording system you will need to supply the correct power Refer to Chapter 6 Advanced Installation Topics for more information Kinemetrics Operating Basics Zero Adjusting the FBA After the FBA 23 has been installed and leveled the accelerometer s DC offset should be 0 0V 25mV Zeroing the FBA ensures that when the recorder receives and records data from the FBA 23 that data will have minimal DC offset and also that the recorder can use its full scale range Methods of Measuring the DC Offset If the FBA 23 is near the recorder you may zero the accelerometers by using the recorder as if it were a DVM Use the AQ DVM command in QuickTalk Terminal Mode If the FBA 23 is located at the end of a long cable you have two choices Choice 1 Remove the cover from the unit and measure the offset directly at the accelerometer circuit board In this case you will directly connect a DVM using EasyHook leads to the FBA circuit board This method has th
57. required to restore the coil position The supply should be low noise less than 50 mV of ripple Caution Incorrect power to the FBA 23 can cause incorrect readings and may damage the sensor Never supply more than 15V to the unit and be sure the connections are the correct polarity There is no protection provided against reversed polarity connections The FBA 23 produces a single ended 2 5V output that is referenced to ground The recorder input should be matched to this output for optimum performance The output impedance of the FBA 23 is 500 Q which is used to ensure the unit is stable under capacitive loading from a long cable Normally data loggers have an input impedance of 100 kQ or more and the 500Q output impedance is insignificant The FBA 23 is calibrated for 100 kQ However if your data logger has a lower impedance you should consider the effect this has on the full scale output of the sensor For example a data logger with a 10kQ input impedance would read only 2 38V for a full scale signal This represents an error of approximately 5 FBA 23 Force Balance Accelerometer 6 7 Calibration Sequence Grounding To produce the functional test sequence the recorder must control the Cal and Undamp line to the FBA 23 If the recorder cannot produce a functional test it is still very important that these lines be held at the correct potential The CAL line must be connected to a potential of lt 2 5V when it is not oper
58. rer FI WHITE EFN L SIGNAL OUTPUT TA L CHi L SIGNAL COMMON B BLACK M cH Sauk E M CH1GND N C V SIGNAL OUTPUT ZC GREEN Mm do V SIGNAL COMMON D BLACK B cH2 V SIGNAL SHIELD LE EN PP CH26ND N C GNAL OUTP E D HAC CH3 T SIGNAL COMMON F BLACK D CH3 T SIGNAL SHIELD G a ER CHSCND N C CAL 1 Ha E CALDAC j BLACK n HE Mi 12VDC 75 RED iH J 12V0C 12VDC TN BLACK H H 12VDC POWER COM TR ENS if K POWER COM CASE GROUND T ps n U PGP 7 U El BR ever H E S N C J N CABLE TYPE BELDEN T N C a P N 9874 V DRAIN N C 840356 CONNECTOR CONNECTOR MS3106F 20 29P 850407 2 16 851 06EC14 19PNS5O Installation Basics 4 Once you have run the wires through the correct holes in the grommet strip 1 8 off the wire tips then solder tin them as shown in Figure 2 13 Figure 2 13 The foil tape and the stripped and tinned wires SE 4 amp ps Final Assembly of the Recorder End If you are assembling the recorder end continue through this section until you are finished If you are assembling the FBA 23 end go to Final Assembly of the FBA 23 End To solder the wires into the recorder mating connector 1 Start at the bottom and work toward the top pin A marks the top soldering the wires into the connector Note When cool the soldered joints should have a smooth shiny surface Use enough solder to just fill the connector cup 2 When done with the solder
59. t access screws should be screwed in snugly Getting Started 2 Installation Basics Requirements for Installation Listed below are the tools supplies and equipment required to install the FBA 23 in a typical configuration remotely from a Kinemetrics recorder and attached to that recorder via an external FBA 23 cable However certain installations may require additional tools supplies or equipment depending on specific sites and needs These instructions also assume that all civil engineering work concrete pad conduit etc has been finished Caution Kinemetrics recommends you collect all required tools equipment and supplies before taking the FBA 23 or any related components into the field Required Tools Soldering iron electric or butane powered approx 50 watts Heat gun electric or butane powered Small portable vise Screwdrivers 1 8 flat blade 1 4 flat blade Wire cutters Wire strippers Long nose pliers Utility knife An extension cord or small generator for AC power if butane powered soldering irons and heat guns are not available Hammer drill with 1 2 concrete bit or a chuck to hold the Red Head anchor for self drilling m Kinemetrics manual anchor drill P N 100208 if you are not using a hammer drill m Wrench for 1 4 20 bolt m Hammer m Safety glasses FBA 23 Force Balance Accelerometer 2 3 Required Supplies Adequate length and appropriate type of cable for connecting
60. te these poles The FBA 23 is produced with 0 25 0 5 1 2 and 4 g full scale sensitivity This corresponds to the following nominal absolute sensitivity at DC Full Scale Range gs Absolute Gain Vs m Accurate calibration values for each sensor are given on the sensor s calibration card included with the unit Reference Practical Damping amp Natural Frequency The calibration card for the FBA 23 also contains the natural frequency and damping of the sensor Thus to most precisely determine the poles and zeroes these values can be substituted into equations 2 and 3 Second Order Transfer Function Poles for Nominal FBA 23 Parameters If we assume that the FBA 23 s natural frequency is 50 90 or 100 Hz and the damping is precisely 0 707 we can obtain the following nominal poles for the second order representation for constant input acceleration Pole P1 Pole P2 FBA natural Real Imaginary Real Imaginary frequency component component component component Hz rad s rad s rad s rad s 50 222 1 222 1 222 1 222 1 90 399 8 399 8 399 8 399 8 444 2 4442 4442 4442 We can get a further improvement in the accuracy of the model by considering the pole due to the low pass RC filter in the post amplifier This pole is dependent on the natural frequency and range of the sensors Pole PoleP3 FBA natural FBA range g Real Imaginary frequency Hz component component NETT rad s
61. tput with a full scale output of 2 5V This output corresponds to the input acceleration range of the accelerometer that is factory set at 4g 2g 1g 0 5g 0 25g or 0 1g Full specifications for the unit can be found in Appendix A Kinemetrics is committed to ensuring a successful installation For assistance with planning installation operation or maintenance contact Kinemetrics at the locations listed in the front of this manual Kinemetrics also has an extensive Services Group that can install maintain and analyze the data from your FBA 23 Inspecting the FBA 23 Remove the FBA 23 from its shipping container Caution If you expect to ship the FBA 23 again save the shipping container and packing material Note Although Kinemetrics takes every precaution in packing its systems shipping damage can still occur If you find a problem note the condition of the shipping container Then contact the freight forwarder and Kinemetrics as soon as possible Caution Damage to sensors Dropping the FBA onto a hard surface can damage the sensors FBA 23 Force Balance Accelerometer 1 1 Figure 1 1 The FBA 23 Mounting hole ie ion arrov eve TN A N e ER NA I ment Adjustable leveling foo for or f three Examine the FBA 23 Its black case should appear securely sealed and show no sign of dents or scratches The bubble level glass should appear undamaged and the box s three large zero adjustmen
62. ts natural frequency This is a useful check of the unit s operation A 12V pulse is required to undamp the system and in normal use this line should be grounded Reference Pole Zero Representation of the FBA 23 The Dynamic System The FBA 23 accelerometers are closed loop force feedback sensors measuring the relative displacement of moving mass with respect to the sensor case Their voltage output is proportional to the input acceleration in the frequency band from DC to 50 Hz optionally to 100 Hz The sensor s properties are essentially equivalent to a second order dynamic system with one pair of complex conjugate poles The sensors transfer function TF depends almost entirely on the electronic components rather than on the mechanical components of the sensors The influence on the Transfer Function of the physical mass mechanical damping spring elements and internal RC low pass filter in the trans conductance amplifier stage within the closed loop path of the sensor are negligible for most applications For more accurate transfer functions at high frequencies above 20 Hz you can take into account the additional pole of a passive low pass RC filter in the post amplifier stage of the sensor electronics The sensors are factory calibrated as second order systems Nominal resonant frequency is 50 Hz or 100 Hz or 90 Hz for a 4 g unit and nominal relative damping is 0 707 Resonant frequency relative damping and static gain are f
63. ttended use but we recommend that you perform the following checks a minimum of once a year If the FBA 23 is connected to an Altus recorder equipped with a modem this maintenance check can be performed remotely and more frequently See the Altus recorder manual for more details Adjust the Accelerometers If the offset of the FBA 23 sensors measures more than 25 mV you should adjust them Refer to Chapter 3 for instructions on adjusting the zero offset Complete a Functional Test Kinemetrics recommends that you perform a functional test on the accelerometer at each service visit to check that the unit is operational and to keep as a baseline record for future visits Refer to Chapter 3 for instructions on performing the functional test If the unit is connected to an Altus or other Kinemetrics recorder refer to the recorder s manual for instructions on performing the functional test Refer to Chapter 6 if the unit is connected to a non Kinemetrics data acquisition system Desiccant Replacement The FBA 23 contains a small capsule of desiccant that is designed to maintain the inside of the unit at a low humidity level If the case is open for a long period of time opened repeatedly for inspection or adjustment or in very humid conditions this capsule should be replaced New desiccant can be ordered from Kinemetrics as P N 700233 Be sure to follow Electro Static Discharge ESD precautions when the sensor case is opened Caution Potential e
64. u should have 6 pieces approx 3 8 x 1 and 1 piece approx 1 4 x 3 FBA 23 Force Balance Accelerometer 2 21 Figure 2 20 Preparing 3 8 wide foil tape from 1 foil tape To assemble the FBA 23 end mating connector Gather the parts listed in Table 2 4 and slide them over the cable s outer jacket a couple of feet up it so they are out of the way until needed Make sure to slide them over the jacket in the order listed top to bottom in Table 2 4 Refer to Figure 2 23 if you need help in identifying these components Table 2 4 Slide parts over jacket in this order Part Name KMI P N Connector Back Shell part of KMI 850407 Rubber Boot 850034 Thermofit Tubing 851186 Braid 20 AWG 1 wide 840458 Connector s Plastic Grommet Ring part of P N 850407 Now return to Identical Assembly Procedures and follow it until you come to Final Assembly of the Recorder End Then come back to here and begin the section below Final Assembly of the FBA 23 End To properly solder the wires into the connector 1 Starting at the bottom and working toward the top pin A marks the top begin soldering the wires into the connector following the left side of the schematic in Figure 2 12 2 22 Installation Basics 2 Then slide the grommet and plastic grommet ring forward and up against the connector head shown on the right side of Figure 2 21 3 Now apply two turns of insulating PVC tape between th
65. ur connector shell and pin T are infinite with respect to all the other connector pins With the final cable testing completed disconnect all test equipment The fully assembled cable is ready to connect to the recorder and the FBA 23 CE Compliant Cables To ensure compliance with the electromagnetic emissions requirement of the European Community two FerriShields KMI P N 840734 supplied with CE marked Altus recorders must be installed at each end of the cable as close to the connector as possible Use the cable ties supplied with the kit to keep them in position Connecting the FBA 23 to a Recorder You can now connect the cable to the FBA 23 and the recorder Caution Be sure the recorder is unpowered when connecting the cables 2 26 Installation Basics 3 Operating Basics Operating Concepts The FBA 23 actually consists of three force balance accelerometers inside a single cast aluminum case Each of the three accelerometers is orthogonally mounted on an internal deck plate making the FBA 23 a triaxial accelerometer capable of measuring ground motion simultaneously in the transverse vertical and longitudinal planes Figure 3 1 The FBA 23 FBA 23 Force Balance Accelerometer 3 1 Power to the FBA The FBA 23 s cast aluminum exterior has m A gasket sealed cover to prevent the entrance of moisture and dirt m Three access screws L V and T that cover holes through which the longitudinal vertical and t
66. very low lt 0 3 Q 100 3 Place the two halves of the cable clamp in place then tighten its screws 4 Slide the Thermofit tubing up into place and then shrink it The completed recorder end connector assembly appears in Figure 2 18 Figure 2 18 Completed assembly of the recorder end of cable 840356 2 18 Installation Basics Testing Connector Assembly 1 Now do a buzzing out test on the recorder end of the cable to make sure you connected the proper wires to the proper solder cups per the schematic in Figure 2 12 and that none of the wires were shorted in the assembly process For this testing procedure you need m A digital voltage meter m A utility knife m Awire stripper m A test lead jumper with clips To prepare the FBA 23 end wires as response conductors 1 Strip back 2 of the cable s outer jacket 2 Cut off that 2 along with the cellophane white string and foil shields that it covered 3 Separate the drain wires and insulated conductors 4 Strip off 1 8 of insulation from all of the insulated wires 5 Make sure to position each wire so that its exposed surface has no contact with any other wire Now using the DVM test the connection of the conductor pairs in the recorder end of the assembly First set the DVM to measure resistance in the range of several hundred ohms Then 1 Atthe recorder end of the cable connect one DVM lead to connector pin L at the top right in Figure 2 12 Then
67. y Resistance Active 30 Ohms Cable AWG Cable Resistance per 1000 ft Max Cable Run ft 24 27 70 1083 22 17 50 1714 20 10 90 2452 18 6 92 4335 16 4 35 6897 14 2 73 10 989 The cable assembly technique used for the external K2 is designed to ensure compliance with the requirements of the Emissions and Immunity standards EN 55022 Class A EN 50082 2 of the European Community If grounding the cable shield at both ends with a long cable results in excess noise in the instrument the cable shields can be disconnected at the FBA 23 end This may be required if significant current flows in the shield between the two grounds This may result in better system noise performance However Kinemetrics cannot be responsible for any EMI RFI emissions that may occur due to this change in the cabling If changing the cabling does not solve the problem the case grounds can be reconnected to the FBA 23 and the FBA 23 isolated by placing the mounting feet on isolation washers The mounting screw should not normally provide a path to ground as it contacts the non conductive black anodized surface of the sensor case These isolation washers can be obtained from Kinemetrics as P N 109747 PL Finally a hybrid ground connector can be used With the FBA 23 isolated connect a 4 copper braid from the overall shield of the cable to one side of a 0 1 uF 200 V film capacitor Connect the other side of the capacitor to a Ya copper braid c
68. ziehen Sie das Gutachten eines qualifizierten Elektrikers Ein Nicht in explosionsgefahrdete Umgebung gebrauchen Der FBA 23 hat keinen Explosions schutz von statischen Entladungen oder funkgefahrdeten Bauteilen Benutzen sie die Ger te nicht in Umgebungen mit explosiven Gasen FBA 23 Force Balance Accelerometer Safety Seguridad Simbolos amp T rminos Estos simbolos podrian aparecer en los equipos Kinemetrics o en este manual Significa poner atencion Cuando Usted vea este simbolo en el instrumento referirse a las partes de este manual marcadas similarmente Antes de intentar cualquier servicio en este instrumento Usted tiene que leer las partes relevantes de este manual Si Usted ve este simbolo ponga atencion cuidadosamente Significa un polo a tierra de bajo ruido El item referido debe estar polarizado a tierra para asegurar la operaci n a bajo ruido y ademas sirve como un retorno a tierra para el EMI RFI y transitorios Tal polo a tierra no trabaja como un polo a tierra de seguridad para protecci n contra choques el ctricos Significa una l nea de energ a de Corriente Alterna AC Significa una linea de energia de Corriente Directa derivada de una linea de energia AC Significa una Unidad Sensitiva a Electrostatica Electrostatic Sensitive Device ESD indicando que usted debe tener cuidado y observar todas las precauciones para el manejo de tales unidades Estos t rminos apareceran en este manual Note

Download Pdf Manuals

Related Search

Related Contents

Manual de usuario  Magnum HotShotHD2man_FR.pub  Descarga aquí la ficha técnica de este producto  solutions d`élévation et remorques tactiques militaires    Nuvo-1300af Series User`s Manual Rev A1  Eurofase 22967-015 Installation Guide  Viewsonic Value Series VA2702W  Wells WB-1 User's Manual  LX442 和文カタログ  

Copyright © All rights reserved. Failed to retrieve file