Alpine VOLUME 1.3 Impact Driver User Manual
Contents
1. amplification is a very important feature Although there are obvious audible sounds emitted by most operating equipment it is the ultrasonic elements of the acoustic emissions that are generally the most important For preventative maintenance many times an individual will listen to a bearing through some simple type of audio pick up to determine bearing wear Since that individual is hearing ONLY the audio elements of the signal the results of that type of diagnosis will be quite gross The subtleties of change within the ultrasonic range will not be perceived and therefore omit ted When a bearing is perceived as being bad in the audio range it is in need of immediate replacement Ultrasound offers a predictable diagnostic capacity When changes begin to occur in the ultrasonic range there is still time to plan appropriate maintenance In the area of leak detection ultrasound offers a fast accurate method of locating minute as well as gross leaks Since ultrasound is a short wave signal the ultrasonic elements of a leak will be loudest and most clearly perceived at the leak site In loud factory type environments this aspect of ultrasound makes it even more useful Most ambient sounds in a factory will block out the low frequency elements of a leak and thereby render audible leak inspection useless Since the Ultraprobe is not capable of responding to low frequency sounds it will hear only the ultrasonic elements of a leak By scanning the te2. focuses detected signals ABS plastic with die cut foam one year parts labor excluding abuse details available on request SAFETY ADVISORY PLEASE READ BEFORE USING YOUR INSTRUMENT WARNING Improperuse ofyour ultrasonic detector may resultin death or serious injury Observe all safety precautions Do not attempt to make any repairs or adjustments while the equipment is operating Be sure to turn off and LOCK OUT all electrical and mechanical sources before performing any corrective maintenance Always refer to local guidelines for appropriate lockout and maintenance procedures SAFETY PRECAUTION Although your ultrasonic instrument is intended to be used while equipment is operating the close proximity of hot piping electrical equipment and rotating parts are all potentially hazardous to the user Be sure to use extreme caution when using your instrument around energized equipment Avoid direct contact with hot pipes or parts any moving parts or electrical connections Do not attempt to check findings by touching the equipment with your hands or fingers Be sure to use appropriate lockout procedures when attempting repairs Be careful with loose hanging parts such as the wrist strap or headphone cord when inspecting near moving mechanical devices since they may get caught Don ttouch moving parts with the contact probe This may not only damage the part but cause personal injury as well When inspecting electrical equipment use c
3. Generator is designed to cover approximately 4000 cubic feet 1219 cu meters of uninterrupted space This is slightly larger than the size of a tractor trailer Placement is dependent upon such variables as the size of the leak to be tested the thickness of the test wall and the type of material tested i e is it Sound absorbant or sound reflective Remember you are dealing with a high frequency short wave signal Ifthe sound is expected to travel through a thick wall place the Tone Generator close to the test zone if it is athin metallic wall move it farther back and use low For uneven surfaces it may be necessary to use two people One person will move the Tone Generator slowly close to and around the test areas while another person scans with the Ultraprobe on the other side Do notuse the Tone test in a complete vacuum Ultrasound will not travel inavacuum Sound waves need molecules to vibrate and conduct the signal There are no moveable molecules ina complete vacuum Ifa partial vacuum is to be drawn where there are still some air molecules to vibrate then the Tone Test may be implemented successfully In alaboratory a form of the Tone Testis utilized in seal leaks of an electron beam microscope The test chamber has been fitted with a specially designed transducer to emit the desired tone and a partial vacuum is created A user then scans all seams for sonic penetration The Tone Testhas also been effectively utilized to test tan
4. or window b Manipulate the instrument and use shielding techniques If environmental manipulation is not possible try to get as close to the test site as possible and manipulate the instrument so that itis pointing away from the competing ultrasound Isolate the leak area by reducing the sensitivity of the unit and by pushing the tip of the rubber focusing probe up to the test area checking asmallsectionata time 1 SHIELDING TECHNIQUES Since ultrasound is a high frequency short wave signal itcan usually be blocked or shielded NOTE When using any method be sure to follow your plant s or company s safety guidelines Some common techniques are a Body place your body between the test area and the competing sounds to act as a barrier b Clip Board Position the clip board close to the leak area and angle itso thatitacts asa barrier between the test area and the competing sounds c Gloved Hand USE CAUTION using a gloved hand wrap the hand around the rubber focusing probe tipso that the index finger and the thumb are close to the very end and place the rest of the hand onthe test site so that there is a complete barrier of the hand between the test area and the background noise Move the hand and instrument together over the various test zones d Wipe rag This is the same method as the gloved hand method only in addition to the glove use a wipe rag to wrap around the rubber focusing probe tip Hold the rag in the gloved hand
5. relays contactors junction boxes In substa tions components such as insulators transformers and bushings may be tested Ultrasonic testing is often used at voltages exceeding 2 000 volts especially in enclosed switchgear Since ultra sound emissions can be detected by scanning around door seams and air vents itis possible to detect serious faults suchas arcing tracking and corona without taking the switchgear offline to perform an infrared scan However it is recommended that both tests be used with enclosed switchgear NOTE When testing electrical equipment follow all your plant or company safety procedures When in doubt ask your supervisor Never touch live electrical apparatus with the Ultraprobe The method for detecting electric arc and corona leakage is similar to the procedure outlined in leak detection Instead of listening for a rushing sound a user will listen for a crackling or buzzing sound In some instances asin trying to locate the source of radio TV interference or in substations the general area of disturbance may be located with a gross detector such as atransistor radio or awide band interference locator Once the general areahas been located the scanning module of the Ultraprobe is utilized with a general scan of the area The sensitivity is re duced if the signal is too strong to follow When this occurs reduce the sensitivity to get a mid line reading on the meter and continue following the sound until the loudes
6. so that it acts as a curtain i e there is enough material to cover the test site without blocking the open end of the rubber focusing probe This is ususally the most effective method since ituses three barriers the rubber focusing probe the gloved hand and the rag e Barrier When covering alarge area itis sometimes helpful to use some reflective material suchasa welders curtain or a drop cloth to actas a barrier Place the material so that it acts as a wall between the test area and the competing sounds Sometimesthe barrier is draped from ceiling to floor at other times itis hung over railings D LOW LEVEL LEAKS In ultrasonic inspection of leakage the amplitude of the sound often depends upon the amount of turbulence generated at the leak site The greater the turbulence the louder the signal the less the turbulence the lower the intensity of the signal When a leak rate is so low that it produces little if any turbulence that is detectable itis considered below threshold If aleak appears to be of this nature 1 Build upthe pressure if possible to create greater turbulence 2 Utilize LIQUID LEAK AMPLIFIER This patented method incorporates a UE Systems product called LIQUID LEAK AMPLIFIER or LLA for short LLA is a uniquely formulated liquid substance that has special chemical properties Used as an ultra sonic bubble test a small amount of LLA is poured over a suspected leak site It produces a thin film thr
7. ULTRAPROBE 100 INSTRUCTION MANUAL VOLUME 1 3 Alpine Components Telephone 01424 437000 E mail info alpine components co uk Fax 01424 722502 Web site www alpine components co uk 1 The ULTRAPROBE 100 provides easy accurate leak detection and mechanicalinspection through advanced ultrasonic technology Before you begin testing itis advisable to familiarize yourself with the basic components of your kit 1 PISTOL HOUSING The main component of the Ultraprobe is its pistol housing From back to front let s examine each part A Bargraph Display The display consists of a ten segment LED bargraph that will indicate ultrasonic signal strength A low number of LEDs indicate a low level of ultrasound conversly more intense ultrasonic signals will displaymore LEDs B Battery Level Light This red light turns on only when the batteries need to be replaced NOTE When the trigger on off switch is pulled to the on position the Battery Level Light will flicker on and then stay off This is normal and has no relation to battery condition C Sensitivity Selection Dial There are eight 8 sensitivity levels which read out in related decibels of 0 to 70 Asthedialis turned to the right to 0 the sensitivity of the instrument increases As the dialis turned to the left to 70 the sensitivty decreases Alow level ultrasound emission produces low amplitude Forthis reason the instrument should be in a high sensiti
8. a reduce the sensitivity setting and continue to scan 5 If it is difficult to isolate the leak due to competing ultrasound place the RUBBER FOCUSING PROBE over the scanning module and proceed to scan the test area 6 Listen for a rushing sound while observing the meter 7 Follow the sound to the loudest point The meter will show a higher reading as the leak is approached 8 In order to focus in on the leak keep reducing the sensitivity setting and move the instrument closer to the suspected leak site until you are able to confirm a leak B TO CONFIRM A LEAK Position the Scanning Module or the rubber focusing probe if it is on the scanning module close to the suspect leak site and move it slightly back and forth in all directions If the leak is at this location the sound will increase and decrease in intensity as you sweep over it Insome instances itis useful to position the rubber focusing probe directly over the suspect leak site and push down to seal it from surrounding sounds If itis the leak the rushing sound will continue If it is not the leak site the sound will drop off C OVERCOMING DIFFICULTIES 1 Competing Ultrasounds If competing ultrasounds make it difficult to isolate a leak there are two approaches to be taken a Manipulate the environment This procedure is fairly straight forward When possible turn off the equipment that is producing the competing ultrasound or isolate the area by closing a door
9. ammer will collapse the ball float Since the trap is totally closed no sound will be heard In addition check the thermostatic element in the float and thermostatic trap If the trap is operating correctly this element is usually quiet if a rushing sound is heard this will indicate either steam or gas is blowing through the air vent This indicates that the vent has failed in the open position and is wasting energy THERMODYNAMIC DISC traps work on the difference in dynamic reponse to velocity change in the flow of compressible and incompressible fluids As steam enters static pressure above the disc forces the disc against the valve seat The static pressure over alarge area overcomes the high inlet pressure of the steam As the steam starts to condense the pressure against the disc lessens andthe trap cycles A good disc trap should cycle hold dis charge hold 4 10 times per minute When it fails it usually fails in the open position allowing continuous blow through of steam THERMOSTATIC TRAPS bellows amp bimetallic operate on a difference in temperature between condensate and steam They build up condensate so that the temperature of condensate drops down to acertain level below saturation temperature in order for the trap to open By backing up condensate the trap will tend to modulate open or closed depending on load Ina bellows trap should the bellows become compressed by water hammer it will not function properly The occu
10. at can be noted Use the sensitivity levels of the Sensitivity Selection Dial to assist your test If alow pressure system is to be checked adjust the sensitivity UP toward 8 a high pressure system above 100 psi is to be checked reduce the sensitivity level Some experimentation may be necessary to arrive at the most desirable level to be tested Check upstream and reduce the sensitivity so that the meter reads about 50 or lower then touch the trap body down stream andcompare readings GENERAL STEAM CONDENSATE FLASH STEAM CONFIRMATION Ininstances where it may be difficult to determine the sound of steam flash steam or condensate 1 touch atthe immediate downstream side of the trap and reduce the sensitivity to get a mid line reading on the meter about 50 2 move6 12inches 15 2 30 5cm downstream and listen Flashing steam will show a large drop off in intensity while leaking steam will show little drop off in intensity 12 INVERTED BUCKET TRAPS normally fail in the open position because the trap loses its prime This condition means a complete blow through notapartialloss The trap will no longer operate intermittently Aside from a continuous rushing sound another clue for steam blow through is the sound of the bucket clanging against the side of the trap AFLOAT AND THERMOSTATIC trap normally fails in the closed position A pinhole leak produced in the ball float will cause the float to be weighted down or water h
11. aution High voltage equipment can cause death or severe injury Do nottouch live electrical equipment with your instrument Use the rubber focusing probe with the scanning module Consult with your safety director before entering the area and follow all safety procedures In high voltage areas keep the instrument close to your body by keeping your elbows bent Use recommended protective clothing Do not get close to equipment Your detector will locate problems ata distance When working around high temperature piping use caution Use protective clothing and do not attempt to touch any piping or equipment while it is hot Consult with your safety director before entering the area
12. cked for leakage This Tone Generator is a WARBLE TONE GENERATOR This internation ally patented transmitter sweeps through a number of ultrasonic frequencies in a fraction of a second to produce a strong recognizable Warble signal The warble tone prevents a standing wave condition which can produce false readings and provides for a consistency of testing in practically any material To use the WARBLE TONE GENERATOR 1 Turn Tone Generator on by selecting either LOW for a low amplitude signal usually recommended for small containers or HIGH for high amplitude In high the Warble Tone Generator will cover up to 4 000 cubic feet 121 9 cu meters of unobstructed space When the Tone Generator is on ared light located below the recharge jack in the front flickers 2 Place the Warble Tone Generator within the test item container and seal or close it Then scan the suspect areas withthe Scanning Module in the Ultraprobe and listen for where the warble ultrasound penetrates As an example if the item to be tested is the seal around a window place the Warble Tone Generator on one side of the window close it and proceed to scan on the opposite side To test the condition of the Warble Tone Generator battery set to the LOW INTENSITY position and listen to the sound through the Ultraprobe headphones A smooth continuous warbling sound should be heard Ifa beeping is heard instead then a full recharge of the Warble Tone Generator is
13. indicated To charge the Warble Tone Generator 1 Use the recharger 2 Plug the recharger cord into the recharge jack located on top of the front panel 3 Plug the recharger into the local current supply 4 Acomplete charge will take 7 hours 5 Since there isno memory problem the Tone Generator may be charged after short intervals of use WTG1 WARBLE TONE GENERATOR OPTIONAL 4 ULTRAPROBE APPLICATIONS 1 LEAK DETECTION This section will cover airborne leak detection of pressure and vacuum systems For information concerned with internal leaks such as in Valves and Steam Traps refer to the appropriate sections What produces ultrasound inaleak When a gas passes through a restricted orifice under pressure itis going from a pressurized laminar flow to low pressure turbulent flow Fig 1 The turbulence generates a broad spectrum of sound called white noise There are ultrasonic components in this white noise Since the ultrasound will be loudest by the leak site the detection of these signals is usually quite simple PRESSURE LEAK VACUUM LEAK FIGURE 1 FIGURE 2 A leak can be in a pressurized system or ina vacuum system In both instances the ultrasound will be produced in the manner described above The only difference between the two is that a vacuum leak will usually generate less ultrasonic amplitude than a pressure leak of the same flow rate The reason for this is that the turbulence produced by a vacuu
14. ks before they are put on line piping refrigerator gaskets caulking around doors and windows for air infiltration testing heat exchangers for leaking tubes as a Q C test for automobile wind noise and water leaks on aircraft to test for problems associated with cabin pressure leaks and glove boxes for seal integrity defects 1 Optional 2 PipeThreaded g Batt Tone Generator n UE WTG2SP 8 2 ELECTRIC ARC CORONA TRACKING DETECTION There are three basic electrical problems that are detected with the Ultraprobe 500 Arcing Anarcoccurs when electricity flows through space Lightning is agood example Corona Whenvoltage on an electrical conductor such as an antenna or high voltage transmission line exceeds the threshold value the air around it begins to ionize to forma blue or purple glow Tracking Often refered to as baby arcing follows the path of damaged insulation Although theoretically the Ultraprobe 100 can be used in low medium and high voltage systems most of the applications tend to be in medium and high voltage systems When electricity escapes in high voltage lines or when it jumps across a gap in an electrical connection it disturbs the air molecules around it and generates ultrasound Most often this sound will be perceived as a crackling or frying sound in other situations it will be heard as a buzzing sound Typical applications include insulators cable switchgear buss bars
15. m leak is occuring within the vacuum chamber while the turbulence of a pressure leak is generated in the atmosphere Fig 2 Whattype of gas leak will be detected ultrasonically Generally any gas including air will produce a turbulence when it escapes through a restricted orifice Unlike gas specific sensors the Ultraprobe is sound specific A gas specific sensor is limited to the particular gas it was designed to sense e g helium The Ultraprobe can sense any type of gas leak since it detects the ultrasound produced by the turbulence of aleak Because of its versatility the Ultraprobe may be utilized in a wide variety of leak detection Pneumatic systems may be checked pressurized cables such as those utilized by telephone companies may be tested Air brake systems on railroad cars trucks and buses may be checked Tanks pipes housings casings and tubes are easily tested for leakage by pressurizing them Vacuum systems turbine exhausts vacuum chambers material handling systems condensers oxygen systems can all easily be tested for leakage by listening for the turbulence of the leak A HOW TO LOCATE LEAKS 1 Use the SCANNING MODULE 2 Start off with the sensitivity selection at 0 Maximum 3 Begin to scan by pointing the module towards the test area The procedure is to go from the gross to the fine more and more subtle adjustments will be made as the leak is approached 4 If there is too much ultrasound in the are
16. m sensitivity on the Sensitivity Selection Dial and proceed to reduce the sensitivity until a satisfactory sound and meter level is achieved Contact Module 8 4 HEADSET This heavy duty headset is designed to block out intense sounds often found in industrial environments so that the user may easily hear the sounds received by the ULTRAPROBE Touse simply plug the headset cord into the headset jack on the metered pistol housing and place the headphones over your ears Ifa hard hatis to be worn it is recommended to use UE Systems model UE DHC 2HH Hard Hat Headphones which are specifically designed for hard hat use A Forthose situations in which it is not possible or difficult to wear the standard headphones described above UE Systems has two options available 1 the DHC 1991 Earpiece which loops around the ear and 2 the SA 2000 Speaker Amplifier which is aloud speaker that is compatible with the Ultraprobe headphone output jack 5 WTG 1 WARBLE TONE GENERATOR OPTION The WTG 1 Tone Generator is an ultrasonic transmitter designed to flood an area with ultrasound Itis used fora special type of leak test When placed inside an empty container or on one side of atestitem it will flood that area with an intense ultrasound that will not penetrate any solid but will flow through any existing fault or void By scanning with the Scanning Module empty containers such as pipes tanks windows doors bulkheads or hatches can be instantly che
17. maged ballcanbe heardasa clicking sound whereas a high intensity uniform rough sound may indicate a damaged race or uniform ball damage Loud rushing sounds similar to the rushing sound of a good bearing only slightly rougher can indicate lack of lubrication Short duration increases in the sound level with rough or scratchy components indicate a rolling element hitting a flat spot and sliding on the bearing surfaces rather than rotating If this condition is detected more frequent examinations should be scheduled 10 DETECTING BEARING FAILURE COMPARATIVE TESTING The comparative method involves testing two or more similar bearings and com paring potential differences FOR COMPARATIVE TEST 1 Usecontact stethoscope module 2 Selecta test spot onthe bearing housing Touch that spot with the contact module In ultrasonic sensing the more mediums or materials ultrasound has to travel through the less accurate the reading will be Therefore be sure the contact probe is actually touching the bearing housing If this is difficult touch a grease fitting or touch as close to the bearing as possible Approach the bearings at the same angle touching the same area on the bearing housing Reduce sensitivity if unsure of this procedure refer to SENSITIVITY SELECTION DIAL Listen to bearing sound through headphones to hear the quality of the signal for proper interpretation Select same type bearings under similar load conditions a
18. meter and listen to the sound of the bearing Inthese extreme situations the bearings are usually large 1 2 and up and greased with high viscosity lubricant Most often no sound willbe heard as the grease will absorb most of the acoustic energy Ifasoundis heard usually a crackling sound there is some indica tion of deformity occurring 4 GENERAL MECHANICAL TROUBLE SHOOTING As operating equipment begins to fail due to component wear breakage or misalignment sonic and more importantly ultrasonic shifts occur The accompanying sound pattern changes can save time and guess work in diagnosing problems if they are adequately monitored Therefore an ultrasonic history of key components can prevent unplanned down time And just as important if equipment should begin to fail in the field the ULTRAPROBE can be extremely useful in trouble shooting problems TROUBLE SHOOTING Use the contact stethoscope module Touch test area s listen through headphones and observe the meter Adjust sensitivity until mechanical operation of the equipmentis heard clearly Probe equipment by touching various suspect areas To focus in on problem sounds while probing reduce sensitivity gradually to assist in locating the prob lem sound at its loudest point This procedure is similar to the method outlined in LEAK LOCATION i e follow the sound to its loudest point DDN 11 5 LOCATING FAULTY STEAM TRAPS Anultrasonictestofsteamt
19. n certain metals can be vibrated by the signal By scanning for sonic penetration on the exterior surface or opposite side of the test item with the Ultraprobe the leak willbe detected It willbe heard as a high pitched warble similar to bird chirping 27 The Tone Test incorporates two basic components a TONE GENERATOR an ultrasonic transmitter and the Scanning Module in the Ultraprobe To conductthe test 1 Make certain the testitem has no fluids or contaminants such as water mud sludge etc that can block the path ofthe transmitted ultrasound 2 Place the Tone Generator within the container if itis aroom door or window to be tested place the Tone Generator on one side pointing in the direction of the area to be tested and close or seal so thatthe Tone Genera tor is enclosed within NOTE The size of the test area will determine the amplitude selection of the Tone Generator If the item to be tested is small select the LOW position For larger items use the HIGH position 3 Scan the test area with the Ultraprobe as outlined in LEAK DETECTION procedure i e start with the sensitivity selection at 8 and proceed down When positioning the Tone Generator place the transducer facing and close to the most crucialtestarea Ifa general area is to be checked position the Tone Generator so that it will cover as wide an area as possible by placing itin the middle of the test item How far will the sound travel The Tone
20. nd same rotational speed Compare differences of meter reading and sound quality NOOR It is important to consider two elements of potential failure One is lack of lubrication while the other is over lubrication Normal bearing loads causes an elastic deformation of the elements in the contact area which give asmooth elliptical stress distribution But bearing surfaces are not perfectly smooth For this reason the actual stress distribution in the contact area will be affected by a random surface roughness In the presence of a lubricant film on abearing surface there is a dampening effect on the stress distribution and the acoustic energy produced will be low Should lubrication be reduced to a point where the stress distribution is no longer present the normal rough spots will make contact with the race surfaces and increase the acoustic energy These normal microscopic disuniformities will begin to produce wear and the possibilities of small fissures may develop which contributes to the Pre Failure condition Therefore aside from normal wear the fatigue or service life of a bearing is strongly influenced by the relative film thickness provided by an appropriate lubricant SLOW SPEED BEARINGS Monitoring slow speed bearings is possible with the Ultraprobe 100 Due to the sensitivity range itis quite possible to listen to the acoustic quality of bearings In extremely slow bearings less than 25 RPM itis often necessary to disregard the
21. ons generated at the orifice site will be heard and noted on the meter The sounds of a leaking valve seat will vary depending upon the density of the liquid or gas In some instances it will be heard as a subtle crackling sound at other times as a loud rushing sound Sound quality depends on fluid viscosity and internal pipe pressure differentials As an example water flowing under low to mid pressures may be easily recognized as water However water under high pressure rushing through a partially open valve may sound very much like steam To discriminate reduce the sensitivity touch a steam line and listen to the sound quality then touch a water line Once you have become familiar with the sound differences continue your inspection A properly seated valve will generate no sound In some high pressure situations the ultrasound generated within the system will be so intense that surface waves will travel from other valves or parts of the system and make it difficult to diagnose valve leakage In this case it is still possible to diagnose valve blow through by comparing sonic intensity differences by reducing the sensitivity and touching just upstream of the valve at the valve seat and just downstream of the valve PROCEDURE FOR VALVE CHECK 1 Use stethoscope module 2 Touchdownstream side of valve and listen through headset 3 When necessary if there is too much sound reduce sensitivity 4 Forcomparative readings usually in high pressure
22. orne detection is to go from the gross to the fine If there is too much ultrasound in the area reduce the sensitivity place the RUBBER FOCUSING PROBE described below over the scanning module and proceed to follow the test sound to its loudest point If itis difficult to locate the sound due to a high intensity signal keep reducing the sensitivity and following the meter to the loudest point RUBBER FOCUSING PROBE The Rubber Focusing Probe is a circular shaped rubber shield It is used to block out stray ultrasound and to assist in narrowing the field of reception of the Scanning Module It also increases the sensitivity To use simply slip it over the front of the scanning module or the contact module NOTE prevent damage to the module plug always remove the module BEFORE attaching and removing the Rubber Focusing Probe 3 CONTACT STETHOSCOPE MODULE This is the module with the metal rod This rod is utilized as a wave guide that is sensitive to ultrasound generated internally such as within a pipe bearing housing steam trap or wall Once stimulated by ultrasound it transfers the signal to a piezoelectric transducer located directly in the module housing To use the Stethoscope Module 1 Align the pin located at the rear of the module with the jack in the front end of the Metered Pistol Housing and plug in firmly 2 Touch test area 3 As with the scanning module go from the gross to the fine Start a maximu
23. ough which the escaping gas will pass When it comes in contact with a low flow of gas it quickly forms a large number of small soda like bubbles that burst as soon as they form This bursting effect produces an ultrasonic shock wave thatis heard as acrackling soundin the headphones In many instances the bubbles will not be seen but they willbe heard This method is capable of obtaining successful leak checks in systems with leaks as low as 1x10 ml sec NOTE The low surface tension of the LLA is the reason small bubbles form This can be negatively changed by contamination of the leak site with another leak fluid which can block LLA or cause large bubbles to form If contaminated clean the leak site with water solvent or alcohol check with plant regulations before selecting adecontaminating cleaning agent E TONE TEST Ultratone The Tone Testis an ultrasonic method for non destructive testing which is used when it is difficult to pressurize or draw avacuuminasystem This ultrasonic testis applicable to a wide range of items including CONTAINERS TUBES PIPES HEAT EXCHANGERS WELDS GASKETS SEALS DOORS WINDOWS OR HATCHES The test is conducted by placing an ultrasonic transmitter called TONE GENERATOR inside or on one side of the test item The warble pulse signal from the TONE GENERATOR will instantly flood the test item and penetrate any existing leak hole Depending on configuration and material even thin spots i
24. rapsisapositivetest The main advantage to ultrasonic testing is that it isolates the area being tested by eliminating confusing background noises A user can quickly adjust to recognizing differences among various steam traps of which there are three basic types mechanical thermostatic and thermodynamic When testing steam traps ultrasonically 1 Determine what type of trap is on the line Be familiar with the operation of the trap Is it intermittent or continous drain 2 Try to check whether the trap is in operation is it hot or cold Put your hand near but do noftouch the trap or better yet use anon contact infrared thermometer Use the contact stethoscope module Try to touch the contact probe towards the discharge side of the trap Press the trigger andlisten Listen for the intermittent or continuous flow operation of the trap Intermittent traps are usually the inverted bucket thermodynamic disc and thermostatic under light loads Continuous flow include the float float and thermostatic and usually thermostatic traps While testing intermittent traps listen long enough to gauge the true cycle In some cases this may be longer than 30 seconds Bear in mind thatthe greater the load that comes to it the longer period of time it will stay open ako In checking a trap ultrasonically a continuous rushing sound will often be the key indicator of live steam passing through There are subtleties for each type of trap th
25. rrence of a leak will prevent the balanced pressure action of these traps When either condition occurs the trap will fail in its natural position either opened or closed Ifthe trap fails closed condensate will back up and no sound willbe heard Ifthe trap fails open a continous rushing of live steam will be heard With bimetallic traps as the bimetallic plates set due to the heat they sense and the cooling effect on the plates they may not set properly which will prevent the plates from closing completely and allow steam to pass through This willbe heard as aconstant rushing sound NOTE A complimentary Steam Trap Trouble Shooting Guide is available Contact UE Systems directly by phone or fax 13 Im TEST POINT A TEST POINT D Sk DE m lt i 6 D T TB TEST PO T lt Example of a good valve 6 LOCATING FAULTY VALVES Utilizing the contact stethoscope module in the Ultraprobe valves can easily be monitored to determine if a valve is operating properly As a liquid or gas flows through a pipe there is little or no turbulence generated except at bends or obstacles In the case of a leaking valve the escaping liquid or gas will move from a high to a low pressure area creating turbulence on the low pressure or downstream side This produces a white noise The ultrasonic component of this white noise is much stronger than the audible component If a valve is leaking internally the ultrasonic emissi
26. rtz Although the highest sounds some humans are capable of hearing is 21 000 Hertz ultrasound technology is usually concerned with frequencies yo from 20 000 Hertz and up Another way of stating 8 20 000 Hertz is 20 kHz or KILOHERTZ One kiloHertz is 1 000 Hertz WV UY Since ultrasound is a high frequency it is a short wave signal Its properties are different from audible or low frequency sounds A low frequency sound requires less acoustic energy to travel the same distance as high frequency sound Fig A The ultrasound technology utilized by the Ultraprobe is generally referred to as Airborne ultrasound Airborne ultrasound is concerned with the transmission and reception of ultrasound through the atmosphere without the need of sound conductive interface gels It can and does incorporate methods of receiving signals generated through one or more media via wave guides There are ultrasonic components in practically all forms of friction As an example if you were to rub your thumb and forefinger together you will generate a signal in the ultrasonic range Although you might be able to very faintly hear the audible tones of this friction with the Ultraprobe it will sound extremely loud The reason for the loudness is that the Ultraprobe converts the ultrasonic signal into an audible range and then amplifies it Due to the comparative low amplitude nature of ultrasound
27. st area a user may quickly spota leak Electrical discharges such as arcing tracking andcorona have strong ultrasonic components that may be readily detected As with generic leak detection these potential problems can be detected in noisy plant environments with the Ultraprobe SPECIFICATIONS Construction Circuitry Frequency Response Indicator Sensitivity Selection Power Low Battery Voltage Indicator Headset Transmitter Responsetime Ambient Operating Temperature Range Relative Humidity Storage Temperature Dimensions Weight Probes Scanning Module SCM 1 Stethoscope contact Module Rubber Focusing Probe Carrying Case Warranty Hand held ABS pistol type ultrasonic processor stainless steel sensor enclosures SMD Solid State hybrid hetrodyne receiver 20 100 kHz centered at 28 42 kHz 10segmentLED bargraph red 8 position precision attenuation 9 volt alkaline battery LED Noise isolating type double headset wired monophonic Impedence 16 ohms Over 23 dB noise attenuation Meets or exceeds ANSI specifications and OSHA standards Patented warble tone transmission 300m sec 32 120 F 0 50 C 10 95 noncondensing at up to 86 F 30 C 0 130 F 5 5 x1 x7 9 100z Stainless Steel unisonic single transducer piezo electric crystal type Stainless Steel plug in type with 4 5 Stainless Steel waveguide Circular shaped shields stray ultrasound signals
28. systems a Touch uptream side and reduce sensitivity to minimize any sound usually bring the meter to a mid line 50 reading b Touch valve seat and or downstream side c Compare sonic differentials Ifthe valve is leaking the sound level on the seat or downstream side will be equal to or louder than the upstream side CONFIRMING VALVE LEAKAGE IN NOISY PIPE SYSTEMS Occasionally in high pressure systems stray signals occur from valves that are close by or from pipes or conduits feeding into a common pipe that is near the down stream side of a valve This flow may produce false leak signals In order to determine if the loud signal on the downstream side is coming from a valve leak or from some other source 1 Move close the suspected source i e the conduit or the other valve 2 Touchatthe upstream side of the suspected source 3 Reduce sensitivity until the meter displays a mid line 50 reading 4 Touchatshortintervals such as every 6 12 inches 15 30 5 cm and note the meter changes 5 Ifthe sound level decreases as you move towards the test valve it indicates that the valve is not leaking 6 Ifthe sound levelincreases as you approach the test valve itis an indication of a leak in the valve 14 ULTRASOUNDTECHNOLOGY Mn The technology of ultrasound is concerned with FA sound waves that occur above human perception Pa The average threshold of human perception is 16 500 He
29. t point is located Determining whether a problem exists or notis relatively simple By comparing sound quality and sound levels among similar equipment the problem sound will tend to be quite different On lower voltage systems a quick scan of bus bars often will pick up aloose connection Checking junction boxes can reveal arcing As with leak detection the closer one gets to the emission site the louder the signal Test switchgear transformers etc for arcing tracking amp corona 3 DETECTING BEARING WEAR Ultrasonic inspection and monitoring of bearings is by far the most reliable method for detecting incipient bearing failure The ultrasonic warning appears prior to a rise in temperature or an increase in low frequency vibration levels Ultrasonic inspection of bearings is useful in recognizing a The beginning of fatigue failure b Brinelling of bearing surfaces c Flooding of or lack of lubricant In ball bearings as the metal in the raceway roller or ball bearing begins to fatigue a subtle deformation begins to occur This deforming of the metal will produce an increase in the emission of ultrasonic sound waves Changes in amplitude of from 12 to 50 times the original reading is indication of incipient bearing failure Whena reading exceeds any previous reading by 12 db itcan be assumed that the bearing has entered the beginning of the failure mode This information was originally discovered through experimenta
30. tion performed by NASA on ball bearings In tests performed while monitoring bearings at frequencies ranging from 24 through 50 kHz they found that the changes in amplitude indicate incipient the onset of bearing failure before any other indicators including heat and vibra tion changes An ultrasonic system based on detection and analysis of modulations of bearing resonance frequen cies can provide subtle detection capability whereas conventional methods are incapable of detecting very slight faults As a ball passes over a pit or faultin the race surface it produces an impact A structural resonance of one 1 the bearing components vibrates or rings by this repetitive impact The sound produced is observed as an in crease in amplitude in the monitored ultrasonic frequencies of the bearing Brinelling of bearing surfaces will produce a similar increase in amplitude due to the flattening process as the balls get out of round These flat spots also produce a repetitive ringing thatis detected as an increase in amplitude of monitored frequencies The ultrasonic frequencies detected by the Ultraprobe are reproduced as audible sounds This heterodyned signalcan greatly assist a user in determining bearing problems When listening it is recommended that a user become familiar with the sounds of a good bearing A good bearing is heard as arushing or hissing noise Crack ling or rough sounds indicate a bearing in the failure stage In certain cases a da
31. vity position Ois the high sensitivity position 0 is adB indication of threshold detection for the instrument For higher amplitude signals move the sensitivity to the lefttowards 70 The dial dB indications along with the LED indications in the bar graph may be used to establish dB levels To do this just add 3 dB for each LED bargraph indication to the dB level setin the sensitivity dial EX 0dB onthe sensitivity dial plus 3 LED bargrah levels 9dB 0 9 40 dB onthe sensitivity dial plus 4 bar graphs 52 dB 40 12 D HeadSetJack Thisiswhere you plug inthe headset Be sure to plug it in firmly until it clicks Should atape recorder be utilized this is where the cord forthe tape recorderis inserted Usea miniphone plug E Trigger Switch This is located on the underside of the Ultraprobe 100 The Ultraprobe is always off until the trigger switch is pressed To operate simply press the trigger to turn the instrument off release the trigger 2 SCANNING MODULE This module is utilized to receive air borne ultrasound such as the ultrasounds emitted by pressure leaks and electrical discharges To use make sure it is plugged in to the front end of the metered JE pistol housing by aligning the plug with thereceptical and inserting 7 7 U it firmly Tousethe Scanning Module 1 Plug in to front end 2 Start with the sensitivity selection dial at maximum 8 Scanning Module 3 Startto scan the test area a The method of air b
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