Vallen - Systeme GmbH
Contents
1. Schaftlarner Weg 26a 82057 Icking Munich Germany Tel 49 8178 9674 400 Fax 49 8178 9674 444 email info vallen de http www vallen de vallen Manual ASCO P systeme Frequency range Test frequency APK ASL dB APK ASL dB Derivative kHz kHz attest frequency at 0 5 test frequency ASCO P 90 295 200 OdB 0 7dB ASCO P2 20 84 60 1 3dB 2 dB ASCO P3 240 575 500 1 2 0 3 ASCO P4 195 375 300 0 0 3 ASCO PN1 90 295 200 OdB 0 7dB ASCO PN2 20 84 60 1 3dB 2 dB ASCO PN3 240 575 500 1 2 0 3 ASCO PN4 195 375 300 0 0 3 ASCO PH1 90 295 200 3 4 6 ASCO PH3 240 710 500 0 6 2 1 ASCO PH4 190 385 300 1 8 3 4 ASCO PH5 90 1300 500 0 6 2 2 ASCO PH6 240 1200 500 0 5 2 5 Example for frequency dependence of APK and APK ASL ASCO PN4 as shown in the testing protocol k e APK dB s APK ASL dB i 90 0 5 85 0 0 80 0 5 75 1 0 70 1 5 65 2 0 60 2 5 10 100 1000 kHz 10000 4 4 Revisions ASCO P R1 initial standard version ASCO P R2 developed for option 01 R2 became standard for ASCO P delivered after July 2004 Opto output driving capability increased from 2 5mA to 10mA Internal pullup resistor at Pin 2 Sub D 15 reduced from 2K2 auf 680R ASCO P R3 R5 not relevant ASCO Px R6 Modification for reduced noise especially at low frequencies and change of adjusting procedure and testing protocol automatic ASCO PNx RO ASCO PHx RO like ASCO P R6 ASL Output filters changed to 1 pole 86Hz 4 5 Sp2. Vallen Systeme GmbH are registered manufacturer of the measurement instrument ASCO PXY WEEE Reg Nr DE 68150283 where XY indicate different instrument versions regarding frequency ranges implemented filters and signal conditioning According to German law 10 subparagraph 2 of Elektro und Elektronikgerategesetz ElektroG and in the interests of our customers we accept the obligation for redemption and appropriate disposal of those ASCO P measurements instruments which have been placed by us on the market within the scope of the before mentioned law after August 13 2005 For this we provide the following procedure e Owners of old instruments request our agreement with the return of old instruments The goods to be returned must be described unambiguously and identified by serial number and or the identification numbers e Upon our approval owners may ship the goods free of costs for us e We will dispose the goods according to the relevant laws and regulations on our costs e Goods returned without our approval will not be accepted and returned to the owner on his account With this measure we wish to serve our customers in the best way to properly dispose old instruments and to contribute to re use recycling and proper disposal of electronic waste file ASCOmanE0803 page 11 12 Tel 49 8178 9674 400 Copyright 2008 Vallen Systeme GmbH email info vallen de Fax 49 8178 9674 444 Schaftlarner Weg 26a 82057 Icking Mu
3. 7V 15V supply Pin 2 Pullup See chapter 12 Releases Male connector at ASCO P female at cable T Modification of the Peak Stretcher Time The APK Out signal is clamped to the highest peak amplitude for the duration of the Peak Stretching Time to enable a relatively slow and low cost data acquisition system to measure very short AE peak amplitudes over a very large dynamic range The Peak Stretching Time comes usually set to 51 53ms adjustable at pot P3 Removing jumper JP2 disconnects C43 and shortens the Peak Stretching Time to about 0 5ms Values between can be realized by modfiying C43 C431 By enlarging R25 stretching times up to 1 second and more can be achieved See eS ms JP2 ee a a a factory setting factory setting 47kOhm notused 33nF D 5 47kOhm not used 3 factory setting 8 Modification of the Pulse Width Opto Coupling Output ASCO P comes with a pulse width of 52 to 62ms and can be modified as shown in the table ms 52 62 1 5MOhm 100nF 300kOhm 100nF rr 30kOhm 100nF The pulse width restarts with each threshold crossing This can cause a larger pulse width All resistors are of model SMD 1206 1 metal film all capacitors SMD 1206 5 COG if values are not produced from COG material X7R 10 higher temperature coefficient file ASCOmanE0803 page 6 12 Tel 49 8178 9674 400 Copyright 2008 Vallen Systeme GmbH email info vallen de Fax 49 8178 9674 444 Schaf
4. are subject to change as developments are made Weight 5 11 Temperature range Humidity 5 12 Accessories available ASCO NTE Power supply for 230Vac ASCO CBL Cable D Sub15pol to 2 BNC DAQ1 Set Data acquisition set for USB Bus 300g Environment conditions 30 to 70 C 0 90 not condensing For sensors modifications special versions or PC integration please contact us Specifications subject to change as product developments made file ASCOmanE0803 page 5 12 Tel 49 8178 9674 400 Fax 49 8178 9674 444 Copyright 2008 Vallen Systeme GmbH Sch ftlarner Weg 26a 82057 Icking Munich Germany email info vallen de http www vallen de vallen Manual ASCO P systeme 6 l O Connector Pinout 15pol SUB D With Reset Input low the peak stretcher output g D APK Out follows the logarithmic output without 15 Output Filter delay Reset Input is usually open For handshake GND with a microprocessor 6 Input Reset Threshold Input can stay open if Opto Out not 13 GND used Threshold does not influence ASL Out or 5 Input Threshold APK Out 12 GND A Output APE Opto Out can be connected to GND Pin 11 11 GND Opto Out to the Pull Up resistor Pin 2 if the 2 Output Opto isolation is not desired 10 Output Opto Power and Power are in parallel to the separate Z__ Internal Pull up 2 2k to 5V 5 5mm power socket connecting jack plug not 9 Power required if l O connector is used for power Power
5. dBac lt 10MA APK ASL Offset P1 0 0 7dB 200 100kHz P2 P2N 1 3 2 7dB 60 30kHz P3 P3N 0 8 0 3dB 500 250k P4 P4N 0 0 3dB 300 150kHz PH4 1 8 3 4dB 300 150kHz PH3 5 6 0 6 2 2 500 250kHz Smoothing low pass PX 50Hz 12dB Octave PNx PHx 86Hz 6dB Octave Rise time 3dB Peak Stretching Error 1dB 35 95dBar 5 6 Reset Input 2 5V or open Peak Stretching normal OV Peak Stretching off 5 7 Opto Output normal open 5V max activated at threshold crossing see para 12 52 62ms no post trigger 5 8 Supply Voltage Voltage 7 15Vpc Low Noise Power consumption max 100mA Power feed in SubD 15 female or jack plug Control internal to 5V Pulse duration 5 9 Connectors ASCO side A BNC socket AE sensor e g VS150 M B 5 5 2 1mm jack plug Power supply 7 15V pc plus at inner minus at outer pole C 15 pole D connector male see block diagram Pin 1 Power 7 to 15Vpc OV pin 9 Pin 2 Internal Pullup to 5V see chapter 12 Pin 3 Optocoupler Pin 4 Output APK 0 4V Pin 5 Input Threshold 0 4 24V Pin 6 Input Reset 0 5V Pin 7 do not connect for manufacturer test only Pin 8 Output ASL 0 4 24V Pin 9 GND Power Pin 10 Optocoupler Pin 11 14 GND Power Pin 15 Output Filter 2Vpp 100 dBae 5 10 Housing aluminium profile lt 130 a 8 Power I O DB15 Sensor 7V 15V BNC P 105 gt p 130 E l Spezifications
6. 1 5 29 1 1 pole 86Hz ASCO PH1 90 295 Tus 0 813 1 125 20 3 28 1 1 pole 86Hz ASCO PH3 240 710 Tus 0 935 1 347 23 4 33 7 1 pole 86Hz ASCO PH4 190 385 Tus 0 920 1 323 23 0 33 1 1 pole 86Hz ASCO PH5 90 1300 Tus 0 971 1 243 24 3 31 1 1 pole 86Hz ASCO PH6 240 1200 Tus 0 958 1 330 24 0 33 8 1 pole 86Hz The bold printed derivatives PN1 PN2 PH3 and PH5 are preferred on stock for short delivery time 4 3 Property APK ASL APK and ASL are derived from the same logarithmic output but APK represents the peak amplitude and ASL the average The average is gained by a smoothing low pass This causes a difference between the levels of APK e g of a sineburst and ASL e g a continuous sinewave which increases with decreasing frequency The following table shows this difference at 2 frequencies for each ASCO P derivative at the so called testing frequency and half the testing frequency Each ASCO P derivative is adjusted such that the APK Output at the testing frequency is optimized for lowest deviation from the input burst signal The testing protocol coming with the ASCO P shows among others the frequency dependence of the APK output and the difference APK ASL example below Negative values for APK ASL appear if the APK risetime hinders the APK level to reach the peak level For the measurement of short bursts of frequencies above 300kKHz we recommend the derivatives ASCO PHx file ASCOmanE0803 page 3 12 Copyright 2008 Vallen Systeme GmbH
7. Hx are successors of the ASCO Px They differ from ASCO Px with respect to the low pass at the ASL Output For the ASCO Px this low pass is 2 pole 50Hz for ASCO PNx and PHx this low pass is 1 pole 86Hz The 1 pole filter allows the determination of an energy proportional result for each detection interval An optimum is reached for 5000 Scans s For such a high sample rate we recommend to enable the short PST Peak Stretching Time by removing jumper JP2 This also allows to resolve hit rates up to 1000 s and more 4 1 3 ASCO PHx With the ASCO PHx the usable frequency range is 90 to 1300kHz In addition to the higher frequency range this derivative realizes a considerably shorter rise time of the APK Output 7us instead of 25us This implies an increased electric noise For higher frequencies we recommend higher sampling rates and also the shorter PST 4 2 Properties of ASCO P Derivatives typical frequency APK ASL APK ASL APK range rise time noise noise noise noise Derivative kHz us 50R V 50R V 50R dB 50R dB ASL filter ASCO P1 90 295 25us 0 654 0 948 16 4 23 7 2 pole 50Hz ASCO P2 20 84 25us 0 428 0 591 10 7 14 8 2 pole 50Hz ASCO P3 240 575 25us 0 954 1 233 23 9 30 8 2 pole 50Hz ASCO P4 195 375 25us 0 858 1 163 21 5 29 1 2 pole 50Hz ASCO PN1 90 295 25us 0 654 0 948 16 4 23 7 1 pole 86Hz ASCO PN2 20 84 25us 0 428 0 591 10 7 14 8 1 pole 86Hz ASCO PN3 240 575 25us 0 954 1 233 23 9 30 8 1 pole 86Hz ASCO PN4 195 375 25us 0 858 1 163 2
8. Valen Vallen Systeme GmbH systeme The Acoustic Emission Company User Manual for the Family of Acoustic Emission Signal Conditioners ASCO PXx Contents PAD DIIGCAUIONS cieni E E A E EE E E OA EE 2 2 BROCK GAO AI assar EEEO E EEE ASEENA 2 2 DENSOS E E E E E 2 A ACOP Gr A CS serrin E E E E EEO 3 4 1 Overview on all ASCO P Derivatives ccccccccceececceeeeeeeceeeeeceeaeeeeseeeeeseeeeeseucesseeeesseeeesaeeeseeeeeseeeess 3 Mitel ASCO PX aro a a E A A A E O N 3 ala ASCOPNS PHXaiikiina ii a E E EAE EE S TE 3 alo ASCO PHX sarae oE EAA E A SEDE AEE Er O EA 3 4 2 Properties of ASCO P Derivatives typical ccccccccceeeeeeeeeeeeeeseeeeeseeeeeeeseeseeeseaeeeesseeeesaeeeeeseeeeeeeeas 3 43 Property APK ASL sasinen axtavees E E AAEE aia E AE E EE E OEE E NA 3 AA ROVISIONS se serrate seitaie seein actor cigar EE E E D census EEE aaa ses tues au EEEE snaeaees 4 A D Specii VEVSIONS erdee NiE E a EEE seen nodaceeneed uepencedespenesiayeeeendeee lt tueerbaneekanne 4 5 peciNcatons of ASCO P Isisen aaa aa ee eaaa ee 5 5 1 AE Preamplifier SEnSOr CONNMECHOL ccccceeescecceeseeceasececceuseeecseeeecsaueeecseaeeessageeeesegseesssuseeesseageees 5 F L SRO a E E A E A 5 So FOT OUDOT oee es eee eise cet va asledie een mn coe sep deed oceans home saeden vee soot pe adage ycee esse cdeet ms coataseeaees 5 54 APK O tput Peak AMpPptUdE ee vaxecoutscnetecutepnastueceedsachyaedsiee aa a E kaaa EE EER 5 5 5 ASL Output Avera
9. ecial versions ASCO P O1 available since February 2004 Like ASCO P1 R2 from 12 2005 like ASCO P1 R6 Supply voltage 22 26V instead of 7 15V feed in this higher voltage ONLY at the JACK PLUG NOT at the SubD15 connector Peak Stretching Time 1 5ms Opto Output Pulse Width 1ms file ASCOmanE0803 page 4 12 Tel 49 8178 9674 400 Copyright 2008 Vallen Systeme GmbH email info vallen de Fax 49 8178 9674 444 Schaftlarner Weg 26a 82057 Icking Munich Germany http www vallen de Manual ASCO P 5 Specifications of ASCO Pxx Derivative overview in paragraph 4 5 1 AE Preamplifier Sensor connector Input impedance gt 10MOhm parallel 10pF Meas range 100MVpx 100dB e Gain 20dB Noise Inp 50R P1 PN1 24dBage P2 PN2 16dBae P3 PN3 P4 PN4 31dBage PHx 34dBage P1 PN1 PH1 90 290 P2 20 85 P3 240 575 PH3 240 710 P4 PH4 195 380 PH5 90 1300 PH6 240 1200 Freq range kHz Filter roll off high pass 24dB Octave low pass 12dB Octave Charakteristic Butterworth 5 2 Threshold Input Voltage like ASL Ri 10kKOhm 5 3 Filter Output Voltage approx 2Vpp 100dBage equals 0 2Vpp sensor Max load 5mA 5 4 APK Output Peak Amplitude Voltage 4 0V 100dBae 200kHz 40mV dBae lt 10mMA Px PNx 25us PHx 7us sine burst excitation 51ms from last amplitude increase 0 5ms w o jumper Fehler 1dB 40 95dBar PHx 45 100 5 5 ASL Output Average Signal Level Voltage 40mV
10. es friction corrosion and more The ASCO P conditions the AE signal such that it can be recorded and evaluated by using a low cost PC plug in data acquisition card and a minimum of software that shows voltage over time With ASCO P the integration of AE measurements into an industrial application becomes straight forward and very cost effective The ASCO P forms a very useful completion of your mechanical testing machine tensile bending scratch tests etc because it provides valuable information on the damage process in your sample with very little effort 2 Blockdiagram Output Filter Filter Low Pass Output ASL Module Log Peak Pream Output APK BNC Input Reset Com palse Opto 7 Output Optocoupler parator coupler Output Optocoupler Input Threshold The AE signal delivered by a piezo electrical AE sensor is fed in over a BNC connector and amplified by a low noise preamplifier A filter module rejects undesired frequency components The high frequency signal is rectified and the logarithm is obtained This signal is smoothened by a low pass filter and presented at the Output ASL average signal level In parallel the logarithm signal is processed by a peak stretcher which holds even very short peak values for a defined time period and presents it at the Output APK AE peak amplitude The log signal is compared against a threshold fed in as analogue voltage e g the analogue output of a PC card When the signal exceeds the se
11. ge Signal Level cccccsssceccssceecesseeecceueeesseseeeceeeeesseaseeessageeecsegseesseageesssnseees 5 OO RoS IU o e E coca os deed cee colet soiedees ree apde eaese eeucoeee teu A 5 IA IO DU eaa E E cate ee coates eens 5 OO APON y AGE sre E E O E E E E 5 39 CONECO ASC OSI srai EES E E 5 5 10 Housing aluminium OVOTIG J cinctanevascct lt necochexerdeucsspeasisucenccnalocwsisnwbaynaseie hap AS EPT 5 1 IV MOMS INU CONTU ONS seer E E a E A 5 NZ ACE CS SONOS aV aO n a E E a ATE EA 5 6 N0O Connector PINGUL issia nA EEA ee ee ee eee ee 6 7 Modification of the Peak Stretcher TiMe snnunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nenne 6 8 Modification of the Pulse Width Opto Coupling Output eee ceceeeeeeeeeeceeeeeceeeeeeeneeseeeeeseeeeees 6 9 Adjustments not recommended without being trained ccccsceeeessseeeeeeeeeeeeeeseeeseesneeseeneessneneenses 7 10 Component Location on the Printed Circuit Board cccccccccsceeeeeeeeeeeeeeeeeeeeseneeeseneeseaneeseaeesseneeneaes 7 10 1 Top side R251 R301 not inserted Parallel to R25 R30 for easy modification ceeeeeeeee T 10 2 BOOM SIdE orasenesti ae ee ene ee me ee ee ee ee ieai T 11 Details on ASCO P ReSUIts eee cececeee ee eeceneeeeeseeseaa esses esses eeseaseseaaeseeeaeesaaseesaaeeesaseeseasesseanessoneessons 8 DAP PAC OIG IGA CONG sarae nance seeped dementias seianoeee seen siece seh es snemattiens
12. l eevee EA EEEE E EE 8 11 2 ASL Average Signal Level viciiwsinnnsoutareausnsncuasiaasia asuay cove eaae anina Esna Naa aana E EA EAE Eaa 9 11 2 1 How the ASL is obtained miiirrersrussserninroiterstanrnsnnn dannu tadeastetiddces weeds aaa aia aN 9 1e POWO S Toe E E AE AE a E ER E E 10 AEE E E E EA E EE E E E E A E ETEA A sede segues aoe TA 10 12a C ONNO CUON arnon EE E EE E E E AE TEE AE SENE EEEE E ES 10 12o Se MS Ol ODINO reenen aA E E E E E EE EEE A E ERES 10 12 4 Testing Environment and NoISC ccccccccssececeececesecenseecsseeeeaseeceaececeuececageceeesecsageessaeeeseaesensagess 11 l2 TVS UPA SU a eat tlm eect EA EEEE EE E EA E E E 11 13 Regulations concerning redemption and disposal of ASCO P a sassnnsssnnnnnnnnennnnnnnnnnnnnnnnnnnnnnnnnnnnne 11 file ASCOmanE0803 page 1 12 Tel 49 8178 9674 400 Copyright 2008 Vallen Systeme GmbH email info vallen de Fax 49 8178 9674 444 Sch ftlarner Weg 26a 82057 Icking Munich Germany http www vallen de vallen Manual ASCO P systeme 1 Applications The ASCO P Acoustic Signal Conditioner with Peak Detector lets you detect damage mechanisms such as crack formation crack growth fiber breakage delamination debonding of surfaces and others as they happen This works with all brittle materials e g fiber reinforced plastics composites ceramics metals and many more In addition the ASCO P can detect and monitor leaks partial discharge particle impact flow turbulenc
13. lected threshold a pulse is generated fed over an optocoupler and presented at the pins Optocoupler and Optocoupler Depending on the application this can trigger e g an alarm or an image record an event counter or a more detailed analysis of the incoming data 3 Sensors For the detection of rapid changes in the material such as crack formation and growth fracture partial discharge etc we recommend our sensor VS150 M which has the peak sensitivity at 150kHz For the detection of leak or friction in the range 25 to 80kHz we recommend the VS30 V For high frequencies up to 1 3MHZ e g from thin fiber reinforced materials or paper the VS700 D is well suited In order to meet special requirements for instance high temperatures different sensors have to be chosen Sensor and the model of the ASCO P family have to be chosen according to the frequency range of interest file ASCOmanE0803 page 2 12 Tel 49 8178 9674 400 Copyright 2008 Vallen Systeme GmbH email info vallen de Fax 49 8178 9674 444 Sch ftlarner Weg 26a 82057 Icking Munich Germany http www vallen de Manual ASCO P vallen systeme 4 ASCO P Derivatives 4 1 Overview on all ASCO P Derivatives 4 1 1 ASCO Px The Suffix xX is replaced by a number which specifies together with P PN or PH a frequency range according to table 4 2 ASCO PXx is identical to the former ASCO P with filter module FMx 4 1 2 ASCO PNx PHx The derivatives ASCO PNx und P
14. losed cable supplied only if ordered to make the APK and ASL signal available at separate BNC connectors female You may also have a cable customized to fit your data acquisition system Minimum requirements for the data acquisition system for use with the ASCO P analogue DC input 0 4V The required sampling rate and settling time depends on the selected Peak Stretching Time PST For 50ms PST 50Hz sampling rate and 20ms settling time are sufficient For 0 5ms PST 5000Hz and 0 2ms settling time are recommended If your data acquisition system has a low pass filter it should not show overshooting The term settling time defines the delay the data acquisition output needs to follow a step wise change of the input signal with desired accuracy 12 3 Sensor Coupling The active area of the sensor the white ceramic plate in case of the VS150 M and the area of your sample where the sensor is to be placed should be as clean as possible It is of particular importance to wipe off grains such as dust sand or metallic particles file ASCOmanE0803 page 10 12 Tel 49 8178 9674 400 Copyright 2008 Vallen Systeme GmbH email info vallen de Fax 49 8178 9674 444 Sch ftlarner Weg 26a 82057 Icking Munich Germany http www vallen de vallen Manual ASCO P systeme The sensor shall be coupled to the sample using a thin layer of couplant Layer thickness less than 0 1mm is desired Put some couplant on the sensitive area of the se
15. nich Germany http www vallen de Manual ASCO P Equipment labelled with the symbol shown left must be disposed separately from unsorted municipal waste within the European Union file ASCOmanE0803 page 12 12 Tel 49 8178 9674 400 Copyright 2008 Vallen Systeme GmbH email info vallen de Fax 49 8178 9674 444 Schaftlarner Weg 26a 82057 Icking Munich Germany http www vallen de
16. nsor then press it force 5 50N against the sample while slightly moving it approx 2mm Couplants that are most commonly used are grease temporary or silicon adhesive for permanent installation For long time tests be sure that the couplant is one that does not evaporate or change its properties e g due to temperature or chemical interaction Avoid using couplants that form brittle bonds these may generate AE signals when the structure deforms under test loading The sensor should be pressed against the sample by an elastic force of about 5 to 50 N we offer magnet hold downs for sensor mounting on ferritic materials Avoid electrical contact between the metallic sensor housing and any conducting surface for instance metal samples contact between the housing and conducting surfaces result in ground loops which are a source of electrical noise Check the coupling by breaking a pencil lead about 3cm away from the sensor An inclined angle approx 30 between the sample surface and pencil is usually best Gently press until the lead breaks The corresponding APK signal should correspond to 90dB minimum on most test structures on extremely thick parts amplitudes from a pencil lead break may be slightly less If the amplitude of the APK signal is too low please remove the sensor remount the sensor including the coupling and repeat the sensor check 12 4 Testing Environment and Noise The ASCO P in combination with an AE sens
17. or is an extremely sensitive measurement instrument It will detect small acoustic signals elastic waves in your sample in the filtered frequency range Try to acoustically isolate your sample against unwanted external influences 12 5 First Analysis We recommend for a first simple analysis to display the ASCO P output against time and if available against external parameters such as load distance number of cycles etc To investigate if a certain process e g crack growth delamination leakage etc can be detected by the ASCO P we recommend the following two sample tests In test one take a sample that follows or contains a known process and in the second test take one which is known not to follow or contain this process Comparing the data should simply indicate if the ASCO P is suited to detect this process in your very special application For ASCO P we provide an easy to operate but versatile data acquisition module well suited for many process monitoring applications ASCO DAQ2 Connected to a PC using the standard USB 2 x interface the 4 channel data acquisition module samples APK ASL external parameters like stress strain pressure temperature etc at a programmable sampling rate and stores the data to file ASCO DAQ2 comes with ready to use powerful AscoDaq software package for data acquisition and analysis including automated monitoring and alarm modes 13 Regulations concerning redemption and disposal of ASCO P We
18. or signal Low passing the logarithmic envelope provides the ASL Output As the pictures shows the ASL signal follows input changes with delay The ASL Output therefore is suited to analyse continuous signals e g from leakage In contrast the APK output is suited to indicate signals from rapid changes such as cracks fracture partial discharge and more For the energy analysis of short bursts the derivatives ASCO PNx and PHx are optimized he ASL Output Spim O Time 500s Diw LAA Sensor Signal Input 20r Di Time 500s Div The combination of both outputs ASL and APK in one module makes the ASCO P a very versatile AE frontend module 12 How to start 12 1 General The ASCO P as well as the sensor are high tech components In order to avoid damage prevent them from mechanical shock e g do not drop them on the floor 12 2 Connections The ASCO P requires a 7V 15V DC low noise power supply We recommend to use a linearly regulated power supply rather than a so called switched power supply on reasons of lower noise You can supply this voltage to the ASCO P either via the jack plug or via the 15pol Sub D connector for details see section 5 If it is ordered we also supply the cable to connect the sensor to the BNC connector of the ASCO P The sensor to ASCO P cable is sensitive to folding and pulling from the connectors Data output is the 15pol Sub D connector of the ASCO P You can use the enc
19. stretching time CHT Peak Stretcher Output TWOI Time 2U0ys Div This example demonstrates CHE Signal Input r D Time 20ys Div the ASCO s very high dynamic range of 80GB Picture on the right Like above but the gated sine wave input demons trates the rise time of the ASCO P Derivatives Px und PNx have an APK rise time of 25us 3dB 120mV point with 90dB step Derivatives PHx have us rise time and extend the frequency range to higher values thereby increasing the noise For detecting very short spikes e g AE from paper we recommend the ASCO PHS 90 1300kHz CH1 Peak Stretcher Output IwiDiv Time 20us Div or PH6 250 1200kHZ CHE signal Input oirm Div Time 4Ous Div file ASCOmanE0803 page 8 12 Tel 49 8178 9674 400 Copyright 2008 Vallen Systeme GmbH email info vallen de Fax 49 8178 9674 444 Schaftlarner Weg 26a 82057 Icking Munich Germany http www vallen de vallen Manual ASCO P systeme Top signal Ch2 APK Peak Stretching Output Below Ch1 Internal logarithmic envelope signal Peak Stretching Input Lowest curve R1 Sensor signal The picture on the left shows the response of the APK output to an AE sensor signal Peak Stretching Time for better demonstration shortened to about 150us The input peak amplitude of 10mV 80dBae is converted to 3 2V output 40mV dB CH1 Peak Stretcher Input wor Time SUys Div 80dBae gt 3 2V Che Peak Stretcher Ou
20. tlarner Weg 26a 82057 Icking Munich Germany http www vallen de P1 P3 10 10 1 Tel vallen Manual ASCO P systeme Adjustments not recommended without being trained turn right to increase slope of logarithm curve should be 40mV dB turn right to shift up logarithm curve should show 3 6V 90dBae input turn right to increase Peak Stretching Time Component Location on the Printed Circuit Board Top side R251 R301 not inserted Parallel to R25 R30 for easy modification R35 R361 3 LO wy of ASCO2 Place Top A D4 a cg eg 2 bd Ga Gl pg Ee Bo PO pa fd R28 Ta e4 co mg eH Eo Ceo ol EJ Ge ey fe U14 file ASCOmanE0803 page 7 12 49 8178 9674 400 Copyright 2008 Vallen Systeme GmbH email info vallen de Fax 49 8178 9674 444 Schaftlarner Weg 26a 82057 Icking Munich Germany http www vallen de vallen Manual ASCO P systeme 11 Details on ASCO P Results 11 1 APK Acoustic Peak Top signal chan 1 APK Peak Stretcher Output Lower signal chan2 Input signal generated by ACAL3 AE calibrator For better understanding the peak stretching time has been shortened to about 80 us APK starts at 800mV which corresponds to 20dBae 40mV dB or 10uV input which was the noise level of the calibrator The maximum peak amplitude of 100mV corresponds to 100dBage which is converted to 4V 40mV dB This level is kept constant during the peak
21. tput WiDr Time S0pus Div k1 Sensor Signal Input omviDirvy Time S0us Diw 11 2 ASL Average Signal Level 11 2 1 How the ASL is obtained The ASL is a measure for the averaged signal level and somehow related with the energy The ASL is obtained from the sensor signal by see also block diagram on page 2 a first preamplifying the signal to optimize the signal to noise ratio b next applying a frequency filter letting pass only the desired frequency range e g 90 295kHz c then rectifying the filtered signal and converting it to a logarithmic representation to cope with the huge dynamic of AE signals d and feeding this over a low pass filter The output of the low pass filter is what you get as ASL signal Basically the low pass is a combination of resistor R and capacitor C Such a combination has a time constant Tc defined as Tc R C The frequency limit f of this combination is defined f 1 2 PI R C 1 2 PI Tc With PI 3 14159 From this one can derive Tc 1 2 PI f gt low pass of 50Hz Tc 3 18ms gt low pass of 86Hz Tc 1 8ms That means the averaging is done with a time constant of 3 18ms or 1 8ms respectively file ASCOmanE0803 page 9 12 Tel 49 8178 9674 400 Copyright 2008 Vallen Systeme GmbH email info vallen de Fax 49 8178 9674 444 Schaftlarner Weg 26a 82057 Icking Munich Germany http www vallen de vallen Manual ASCO P systeme Upper curve ASL Output Lower curve Sens
Download Pdf Manuals
Related Search