The document discusses the basic principles of ultrasonic testing. It explains oscillation and wave propagation, how ultrasound is generated and received using the piezoelectric effect, and how it is used to inspect materials and detect flaws. Diagrams illustrate longitudinal and transverse wave propagation, reflection, refraction, and techniques for through-transmission, plate, and weld testing.
This document appears to be a field guide or reference text about various types of mushrooms or fungi. It provides brief descriptions of multiple species in other languages, including their identifying characteristics like color, shape, habitat and whether they are edible or poisonous. Each entry includes the species name, short description and sometimes notes on taste or uses. The document uses scientific names and terminology related to mycology.
This document describes a simple VHF receiver that can be built for around $20 using a superregenerative design. The receiver requires no special components or test equipment to construct. It uses a single JFET transistor as a superregenerative detector to provide high sensitivity of around 1 microvolt. The receiver can detect both AM and FM signals between 49-55 MHz with modifications allowing it to receive other VHF bands. With adjustments to the regeneration control and quench waveform control, the receiver can be tuned to receive narrowband FM transmissions with reasonable selectivity.
This document describes how to build a simple and portable shortwave radio receiver using a single hand-wound coil. The receiver requires only basic components, including a variable capacitor, transistor, diode and battery. It can receive international radio broadcasts with its small whip antenna. The document provides detailed instructions on winding the coil, assembling the circuit board, and operating the receiver to tune in shortwave radio signals.
The document discusses the basic principles of ultrasonic testing. It explains oscillation and wave propagation, how ultrasound is generated and received using the piezoelectric effect, and how it is used to inspect materials and detect flaws. Diagrams illustrate longitudinal and transverse wave propagation, reflection, refraction, and techniques for through-transmission, plate, and weld testing.
This document appears to be a field guide or reference text about various types of mushrooms or fungi. It provides brief descriptions of multiple species in other languages, including their identifying characteristics like color, shape, habitat and whether they are edible or poisonous. Each entry includes the species name, short description and sometimes notes on taste or uses. The document uses scientific names and terminology related to mycology.
This document describes a simple VHF receiver that can be built for around $20 using a superregenerative design. The receiver requires no special components or test equipment to construct. It uses a single JFET transistor as a superregenerative detector to provide high sensitivity of around 1 microvolt. The receiver can detect both AM and FM signals between 49-55 MHz with modifications allowing it to receive other VHF bands. With adjustments to the regeneration control and quench waveform control, the receiver can be tuned to receive narrowband FM transmissions with reasonable selectivity.
This document describes how to build a simple and portable shortwave radio receiver using a single hand-wound coil. The receiver requires only basic components, including a variable capacitor, transistor, diode and battery. It can receive international radio broadcasts with its small whip antenna. The document provides detailed instructions on winding the coil, assembling the circuit board, and operating the receiver to tune in shortwave radio signals.
The Maxon SL55 is a handportable radio designed for professional users. It is compact yet rugged with features like long battery life, scanning, encryption, and programmable settings. The radio has 16 channels across VHF and UHF bands with adjustable channel spacing and transmit power up to 5 watts. It performs well in both transmit and receive modes with clear audio and strong selectivity. The SL55 is simple to use but still offers advanced features through programming with accessories.
This document outlines different power and band settings for PMR radios and LPD devices including legal and extended power levels up to 2W for various modes. It also lists combinations of jumper settings labeled JP1, JP2, and JP3 that correspond to the different operating modes. The document provides instructions for toggling between PMR-only and PMR+LPD modes on the radio.
This summary provides an overview of the purpose and content of the document:
The document discusses Walter Russell's cosmology and the goal of developing robust models of Russell's wave theory and applying it to topics like transmutation and free energy. It acknowledges that fully understanding Russell's work requires both studying his published writings as well as contemplation and meditation on the concepts. It aims to help students navigate Russell's work by deconstructing and rebuilding the models in a clear progression.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
This document provides details on the design and performance of two simple software-defined radio (SDR) receivers called DR1 and DR2 for the HF ham bands between 30 kHz and 70 MHz.
DR1 is a single-chip sample and hold receiver using the 74HC4066 chip that achieves good performance such as a sensitivity of 3-5 uV, IIP3 of 28-33 dBm, and SNR of 80 dB despite its simplicity. However, it has an audio image that can interfere in crowded bands. DR2 is similar but uses I/Q sampling to reject the audio image with 35-45 dB rejection. Both receivers connect directly to a PC sound card for processing and demodulation in software
The Maxon SL55 is a handportable radio designed for professional users. It is compact yet rugged with features like long battery life, scanning, encryption, and programmable settings. The radio has 16 channels across VHF and UHF bands with adjustable channel spacing and transmit power up to 5 watts. It performs well in both transmit and receive modes with clear audio and strong selectivity. The SL55 is simple to use but still offers advanced features through programming with accessories.
This document outlines different power and band settings for PMR radios and LPD devices including legal and extended power levels up to 2W for various modes. It also lists combinations of jumper settings labeled JP1, JP2, and JP3 that correspond to the different operating modes. The document provides instructions for toggling between PMR-only and PMR+LPD modes on the radio.
This summary provides an overview of the purpose and content of the document:
The document discusses Walter Russell's cosmology and the goal of developing robust models of Russell's wave theory and applying it to topics like transmutation and free energy. It acknowledges that fully understanding Russell's work requires both studying his published writings as well as contemplation and meditation on the concepts. It aims to help students navigate Russell's work by deconstructing and rebuilding the models in a clear progression.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
This document provides details on the design and performance of two simple software-defined radio (SDR) receivers called DR1 and DR2 for the HF ham bands between 30 kHz and 70 MHz.
DR1 is a single-chip sample and hold receiver using the 74HC4066 chip that achieves good performance such as a sensitivity of 3-5 uV, IIP3 of 28-33 dBm, and SNR of 80 dB despite its simplicity. However, it has an audio image that can interfere in crowded bands. DR2 is similar but uses I/Q sampling to reject the audio image with 35-45 dB rejection. Both receivers connect directly to a PC sound card for processing and demodulation in software
1. Ispitivanje
proizvoda
Ispitivanje ultrazvukom
Opis
metode
Osnovna
oprema
Prednosti
Nedostaci
Varijable
Metode ispitivanja
Oprema za ispitivanje
Ispitivanje proizvoda
Ispitivanje ultrazvukom
doc.dr. Samir Lemeš
<slemes@mf.unze.ba>
Ispitivanje ultrazvukom 2/36
Ispitivanje
proizvoda
Ispitivanje ultrazvukom
Ispitivanje
proizvoda
Metod ispitivanja bez razaranja kod
kojeg se zrake zvuka visoke
frekvencije emituju u materijal s
ciljem otkrivanja površinskih i
dubinskih
d bi kih grešaka
š k
Zvučni talasi prodiru u materijal i
odbijaju se od prelaznih površina
Stepen refleksije uglavnom zavisi od
fizičkog stanja materijala na prelazu,
a manje od osobina materijala
Zvučni signali se skoro potpuno
reflektuju od prelaza metal/gas
Parcijalna refleksija se javlja na
prelazima metal/tečnost ili
metal/čvrsta tijela
Ultrazvukom se otkrivaju
pukotine, odvajanje
laminata, lunkeri, pore,
nemetalni uključci i druge
nehomogenosti
Ispitivanje ultrazvukom 3/36
Ispitivanje
proizvoda
Većina UZ uređaja otkriva greške
praćenjem jedne od sljedećih veličina:
Refleksija zvuka od prelaznih površina ili
diskontinuiteta u metalu
Vrijeme prolaza zvučnog talasa od ulaza
l
č
l
d l
do izlaza
Slabljenje zvučnih talasa apsorpcijom ili
rasipanjem unutar ispitivanog objekta
Karakteristike spektralnog odziva
emitovanog ili reflektovanog signala
Ispitivanje ultrazvukom 5/36
Ispitivanje ultrazvukom 4/36
Ispitivanje ultrazvukom
Ispitivanje ultrazvukom
Ispitivanje
proizvoda
Ispitivanje ultrazvukom
Većina UZ uređaja radi
na frekvencijama
od 0,1 do 25 MHz
Ljudsko uho registruje
zvuk od 20 Hz do 20 kHz
Ispitivanje ultrazvukom 6/36
1
2. Ispitivanje
proizvoda
Osnovna oprema
Ispitivanje
proizvoda
Elektronski generator signala
Sonda koja emituje snop UZ talasa
Kuplant za transfer energije iz sonde
Kuplant za transfer energije u sondu
Sonda za prihvatanje odbijenih UZ
talasa
Pojačalo / demodulator
Displej ili indikator
Elektronski referentni sat
Jako dobra snaga prodiranja u dubinu
materijala (nekoliko metara)
Visoka osjetljivost na male greške
Velika p
preciznost otkrivanja lokacije,
j
j ,
veličine, orijentacije, oblika greške
Dovoljno je da barem jedna površina
bude dostupna
Signal se lako obrađuje elektronski
Mogućnost skeniranja po zapremini
Ispitivanje ultrazvukom 7/36
Ispitivanje
proizvoda
Prednosti metode
Ispitivanje ultrazvukom 8/36
Ispitivanje
proizvoda
Nema opasnosti po osoblje, opremu i
materijale u okolini
Portabilnost (prenosivost)
Generiše izlaz koji se lako obrađuje
j
j
računarom
Ispitivanje
proizvoda
Varijable
Osnovne varijable
koje treba uzeti u
obzir kod UZ
ispitivanja su karakteristike UZ talasa i
karakteristike dijelova koji se ispituju
k kt i tik dij l
k ji
i it j
Od tih varijabli zavisi izbor opreme
Frekvencija ultrazvučnih talasa: treba
naći kompromis između pozitivnih i
negativnih efekata izabrane frekvencije
Ispitivanje ultrazvukom 11/36
Nedostaci metode
Manuelni način rada zahtijeva
iskustvo i veliku pažnju
Za razvoj procedura ispitivanja je
potrebno veliko tehničko znanje
Teško je ispitivati tanke dijelove,
nepravilne oblike, hrapave površine
Teško se otkrivaju defekti koji su
neposredno ispod površine
Potrebni su kuplanti i referentni
standardi
Ispitivanje ultrazvukom 9/36
Prednosti metode
Ispitivanje ultrazvukom 10/36
Ispitivanje
proizvoda
Varijable
Visoke frekvencije: veća osjetljivost,
veća rezolucija, manja penetracija
kod nehomogenih metala (sa većim
zrnom)
Akustična impedanca kombinacije
dva materijala je karakteristika koja
određuje stepen refleksije; ako imaju
istu impedancu, nema refleksije
Jedinica: g/cm2·s
Ispitivanje ultrazvukom 12/36
2
3. Ispitivanje
proizvoda
Varijable
Ispitivanje
proizvoda
Čelik: 4,66·106 g/cm2·s
Aluminij: 1,72·106 g/cm2·s
Bakar: 4,18·106 g/cm2·s
Olovo: 2,45 106 g/cm2·s
2 45·10
s
Zrak: 0,00004·106 g/cm2·s
Staklo: 1,44·106 g/cm2·s
Ulje: 0,15·106 g/cm2·s
Voda: 0,149·106 g/cm2·s
Ugao nagiba
Kad snop UZ talasa pada okomito na
grešku, ugao nagiba je 0° - refleksija
ne mijenja pravac snopa
Kad ugao nagiba
nije 0°, dolazi do
promjene prirode
kretanja talasa i
do prelamanja
Ispitivanje ultrazvukom 13/36
Ispitivanje
proizvoda
Varijable
Ispitivanje ultrazvukom 14/36
Ispitivanje
proizvoda
Intenzitet snopa je energija koja se
emituje po poprečnom presjeku
snopa, a zavisi od amplitude vibracija
čestica
Obično se koristi termin akustični
pritisak (zvučni pritisak) da označi
amplitudu naprezanja koja izaziva UZ
talas u materijalu
Akustična energija je proporcionalna
kvadratu akustičnog pritiska
Ispitivanje
proizvoda
Varijable
Širenje snopa se javlja na većoj
udaljenosti od sonde
Ugao širenja zavisi
od talasne dužine
talasa i od prečnika
ultrazvučne sonde
Slabljenje ultrazvučnog snopa zavisi
od početnog akustičnog pritiska,
dubine dijela koji se ispituje i od
koeficijenta slabljenja (dB/mm)
Ispitivanje ultrazvukom 17/36
Varijable
Apsorpcija ultrazvučne energije se
javlja uglavnom konverzijom
mehaničke energije u toplotu
Rasipanje ultrazvučnog talasa se
javlja zato što većina materijala nije
homogena
Rasipanje se javlja i kod anizotropnih
materijala, kod kojih brzina
prostiranja talasa nije ista u različitim
pravcima
Ispitivanje ultrazvukom 15/36
Varijable
Ispitivanje ultrazvukom 16/36
Ispitivanje
proizvoda
Metode ispitivanja
Dvije osnovne metode su metoda
transmisije i
"puls-eho" metoda
Kod metode
transmisije mjeri se
samo slabljenje signala
Kod puls-eho metode
mjeri se i vrijeme
prolaza i slabljenje
signala
Ispitivanje ultrazvukom 18/36
3
4. Ispitivanje
proizvoda
Metode ispitivanja
Ispitivanje
proizvoda
Puls-eho metoda se koristi za lociranja
grešaka i za mjerenje debljine
Dubina greške se određuje vremenom
od početnog impulsa i eha od greške
Veličina greške se
određuje poređenjem
amplitude
reflektovanog zvuka
s referentnom
amplitudom (od poznate veličine)
Rezultati puls-eho ispitivanja se mogu
prikazati na razne načine:
A-scan: kvantitativni prikaz amplituda
signala i vremena putovanja signala
dobijenih na jednoj tački površine
B-scan: rezultati
duž linije
C-scan: rezultati
po površini
Ispitivanje ultrazvukom 19/36
Ispitivanje
proizvoda
Metode ispitivanja
Ispitivanje
proizvoda
Metode ispitivanja
Ispitivanje ultrazvukom 20/36
Ispitivanje
proizvoda
Blok šema analognog A-scan displeja:
Ispitivanje ultrazvukom 21/36
Blok šema B-scan displeja:
Ispitivanje ultrazvukom 23/36
Metode ispitivanja
Metode ispitivanja
Primjer očitanja
sa A-scan
displeja i sa
osciloskopa
Ispitivanje ultrazvukom 22/36
Ispitivanje
proizvoda
Metode ispitivanja
Blok šema C-scan displeja:
Ispitivanje ultrazvukom 24/36
4
5. Ispitivanje
proizvoda
Metode ispitivanja
Prikaz sa C-scan displeja:
Ispitivanje ultrazvukom 25/36
Ispitivanje
proizvoda
Metode ispitivanja
Oprema za ispitivanje
Poprečni presjeci piezoelektričnih UZ
sondi
Ispitivanje ultrazvukom 29/36
Metode ispitivanja
Ispitivanje pod uglom se koristi za
ispitivanje zavarenih spojeva, cijevi,
limova i pločastih materijala, te
uzoraka nepravilnog oblika, gdje pravi
snopovi ne mogu doći u kontakt sa
i
d ći k t kt
svim površinama
Ispitivanje ultrazvukom 26/36
Ispitivanje
proizvoda
Ispitivanje zavarenih spojeva
Ispitivanje ultrazvukom 27/36
Ispitivanje
proizvoda
Ispitivanje
proizvoda
Metode ispitivanja
Ispitivanje zavarenih spojeva
Ispitivanje ultrazvukom 28/36
Ispitivanje
proizvoda
Oprema za ispitivanje
Sonde za ispitivanje pravim snopom
Ispitivanje ultrazvukom 30/36
5
6. Ispitivanje
proizvoda
Oprema za ispitivanje
Sonde za ispitivanje pod vodom
Prednost ovog ispitivanja je veća
brzina, mogućnost kontrole smjera
snopa i mogućnost automatizacije
Ispitivanje ultrazvukom 31/36
Ispitivanje
proizvoda
Oprema za ispitivanje
Oprema za ispitivanje
Sistem za ispitivanje pod vodom
Ispitivanje ultrazvukom 32/36
Ispitivanje
proizvoda
Kalibracija
Uređaji za mjerenje debljine
Ispitivanje ultrazvukom 33/36
Ispitivanje
proizvoda
Ispitivanje
proizvoda
Kalibracija
Ispitivanje ultrazvukom 34/36
Ispitivanje
proizvoda
Proizvođači
General Electric Inspection
Technologies
Krautkramer / Agfa / Hocking
(www.geinspectiontechnologies.com)
Olympus (www.olympusndt.com)
NDT Systems (www.ndtsystems.com)
Newco (www.newcoinc.com)
UE Systems (www.uesystems.com)
Ispitivanje ultrazvukom 35/36
Ispitivanje ultrazvukom 36/36
6