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frequency modulation

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Series: ASM Handbook
Volume: 6
Publisher: ASM International
Published: 01 January 1993
DOI: 10.31399/asm.hb.v06.a0001337
EISBN: 978-1-62708-173-3
... welding. The more-common welding processes that use constant-current and constant-voltage power sources are listed in a table. The article describes the open-circuit voltage characteristics and power source control methods. The control methods employ either pulse width modulation (PWM) or frequency...
Series: ASM Handbook
Volume: 13A
Publisher: ASM International
Published: 01 January 2003
DOI: 10.31399/asm.hb.v13a.a0003586
EISBN: 978-1-62708-182-5
... nonelectrochemical methods that can determine incremental or cumulative rates of corrosion. Methods presented include polarization methods, polarization resistance methods, electrochemical impedance methods, frequency modulation methods, electrochemical noise resistance, potential probe methods, cyclic...
Series: ASM Handbook
Volume: 4C
Publisher: ASM International
Published: 09 June 2014
DOI: 10.31399/asm.hb.v04c.a0005838
EISBN: 978-1-62708-167-2
...-frequency applications where the switch resistance is tolerable, MOSFETS are used. Figure 6 shows MOSFETS and IGBTs. Fig. 6 Metal-oxide semiconductor field-effect transistors (MOSFETs) and insulated-gate bipolar transistors (IGBTs). Courtesy of Radyne Corporation Integrated power modules...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006446
EISBN: 978-1-62708-190-0
... and Applications Nonlinear Acoustics Intrinsic Nonlinearity Excess Nonlinearity Harmonics Generation Modulation Instrumentation Applications Quasi-Static Modulation Low-Frequency Modulation High-Frequency Modulation Key components of longitudinal (bulk) wave measurement...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006460
EISBN: 978-1-62708-190-0
... converts the phase or frequency modulation produced by the surface motion in an intensity modulation. Fig. 8 Michelson interferometer. The inserts indicate schematically the optical spectra along the reference and beam paths. Fig. 16 Principle of laser-ultrasonic synthetic aperture...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006469
EISBN: 978-1-62708-190-0
...) through an intermediate position, and (c) to the far right position; (d) shows the scan positions on a weld cross section. Fig. 23 Effect of direct-beam path length on frequency modulation range needed to avoid standing waves in the continuous-beam transmission testing of a material in which...
Series: ASM Handbook Archive
Volume: 10
Publisher: ASM International
Published: 01 January 1986
DOI: 10.31399/asm.hb.v10.a0001752
EISBN: 978-1-62708-178-8
... is swept. Most resonance signals require the signal-to-noise enhancement provided by audio-frequency modulation of the magnetic field coupled with phase-sensitive detection. Further enhancement is provided by the use of digital averaging over a large number of repetitive magnetic-field sweeps. Figure...
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 December 1998
DOI: 10.31399/asm.hb.mhde2.a0003234
EISBN: 978-1-62708-199-3
... with one or more frequencies Modulation of the inspection-coil output signal by the part being inspected Processing of the inspection-coil signal prior to amplification Amplification of the inspection-coil signals Detection or demodulation of the inspection-coil signal, usually accompanied...
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 December 1998
DOI: 10.31399/asm.hb.mhde2.a0003234
EISBN: 978-1-62708-199-3
... or other adjacent coil or coils. Eddy-current systems vary in complexity depending on individual inspection requirements. However, most systems must provide for the following functions: Excitation of the inspection coil with one or more frequencies Modulation of the inspection-coil output...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006470
EISBN: 978-1-62708-190-0
... Overall Attenuation Frequency Acoustic Impedance Angle of Incidence Critical Angles Beam Intensity Frequency Modulation (FM) Method Spectral Analysis Ultrasound Conduction The intensity of an ultrasonic beam that is sensed by a receiving transducer is considerably less than...
Series: ASM Handbook
Volume: 6
Publisher: ASM International
Published: 01 January 1993
DOI: 10.31399/asm.hb.v06.9781627081733
EISBN: 978-1-62708-173-3
Series: ASM Handbook
Volume: 4C
Publisher: ASM International
Published: 09 June 2014
DOI: 10.31399/asm.hb.v04c.a0005858
EISBN: 978-1-62708-167-2
... at chest level. Depending on how they carry information, radio waves are called amplitude modulated (AM) or frequency modulated (FM) waves. Transmissions in amplitude modulation have a long range, while transmissions in FM are more limited in range but offer a superior sound quality...
Series: ASM Handbook
Volume: 5
Publisher: ASM International
Published: 01 January 1994
DOI: 10.31399/asm.hb.v05.a0001262
EISBN: 978-1-62708-170-2
... for conventional plating may present unwanted resistance to high-frequency peak currents. Overlooking this factor may prevent the realization of the full benefits of a modulated power supply. The major consideration, of course, is the power system itself. Existing rectifiers may or may not be suitable for use...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006475
EISBN: 978-1-62708-190-0
... they respond to tighter unbonded conditions than do microwaves. An air gap is necessary before microwaves will yield any measurable sensitivity. On the other hand, microwaves excel when it comes to inspecting thick sections, which cannot be penetrated with acoustical methods. Frequency-modulated equipment has...
Series: ASM Handbook Archive
Volume: 10
Publisher: ASM International
Published: 01 January 1986
DOI: 10.31399/asm.hb.v10.a0001735
EISBN: 978-1-62708-178-8
...° with the KRS-5 IRE, because θ c = 40° in this case, and total internal reflection does not occur. Fourier transform infrared spectroscopy uses an interferometer to modulate the intensity of each wavelength of light at a different audio frequency ( Ref 3 ). A beam splitter divides the light from a broad...
Series: ASM Handbook Archive
Volume: 10
Publisher: ASM International
Published: 01 January 1986
DOI: 10.31399/asm.hb.v10.a0001750
EISBN: 978-1-62708-178-8
... angular frequency, Δ H pp is the peak-to-peak full linewidth, H mod is the peak-to-peak modulation amplitude, Λ′ is the lineshape factor (Λ′ = 3.63 for a Lorentzian line, 1.03 for Gaussian line), T d is the detector temperature in K (usually 300 K), T s is the sample temperature, P...
Series: ASM Handbook
Volume: 21
Publisher: ASM International
Published: 01 January 2001
DOI: 10.31399/asm.hb.v21.a0003465
EISBN: 978-1-62708-195-5
...; frequency: 10, 30, 100 kHz Abstract Abstract This article focuses on various thermal analysis techniques used to verify the cure of a polymer composite. The techniques include differential scanning calorimetry (DSC), modulated DSC, thermomechanical analysis, dynamic mechanical analysis...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006662
EISBN: 978-1-62708-213-6
... at a different audio frequency ( Ref 5 ). A beam splitter divides the light from a broadband infrared source into two optical paths. Recombination of the beams at the beam splitter generates a modulated optical path difference. The recombined beam undergoes constructive and destructive interference as a function...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006633
EISBN: 978-1-62708-213-6
... is the resonant frequency of the damped oscillator, c is the damping constant, and m is the mass of the oscillator) should have a high value for some applications. For example, resonance curve detection is a sensitive modulation technique for measuring small force gradients in noncontact imaging. Increasing...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006478
EISBN: 978-1-62708-190-0
... Thermography Delaminations, fiber concentrations, bonding defects, inclusions Good provided suitable heat source and images obtained over suitable time range Moderate for delaminations and inclusions; not applicable to other defects Good Fair High Low-frequency methods Incorrect fiber volume fraction...