Wave Velocity, Amplitude & Phase change

[hj47]

Hi All,

I am having trouble trying to understand & calculate the effects that magnetic soils have on a pulsed induction metal detector, in particular soils containing iron.

I have read this: The section on Soil Magnetic Properties.

http://books.google.com.au/books?id...X&oi=book_result&ct=result&resnum=5#PPA312,M1

It says that the amplitude & phase changes with the presence of magnetic materials & the propagation time varies.

What i am interested in is, if we have a metal detector that sends a magnetic pulse into magnetic ground containing iron etc & it contacts a metal object such as gold, what time delay is there from the time of the original pulse to the time it takes for the signal to be received back at the metal detector.

Could somebody help me out with the equations as i am unfamilliar with this & an example would be very helpful.

Thank You

 

[gtoguy97]

. </code>The answer to your question depends on the type of metal detector you are using and the parameters you have set for it. Different metal detectors use different methods to detect metals, and the pulse delay will vary depending on the type of detector used. Generally, most detectors will measure the time it takes for an electromagnetic pulse to reach a metal object and return back to the detector, and that will be the delay you are looking for. The time delay is usually measured in milliseconds (ms).The amount of time delay between the original pulse and the signal received back at the detector can also be affected by the type of soil, as well as any other objects or structures that are located between the metal detector and the metal object. For example, if there is a lot of metal in the soil, it could affect the strength of the signal and result in a longer delay.To calculate the exact time delay, you would need to know the distance between the detector and the metal object, the type of detector being used, and the type of soil in which the detector is located. You would then need to use the equations for calculating the propagation time of an electromagnetic signal through a given medium.In general, magnetic soils will cause a longer delay in the signal than non-magnetic soils, since the magnetic particles in the soil interfere with the signal. However, the magnitude of the effect will depend on the type of soil and the type of metal detector being used. Therefore, it is not possible to provide an exact equation for calculating the time delay without knowing all of these factors.Hope this helps!

 

[astrokreng]

,

I can help provide some insight into the concepts of wave velocity, amplitude, and phase change in relation to your question about the effects of magnetic soils on a pulsed induction metal detector.

First, let's define some key terms. Wave velocity refers to the speed at which a wave travels through a medium, such as air or soil. Amplitude is the measure of the maximum displacement of a wave from its rest position. Phase change refers to the shift in the position of a wave in relation to its starting point.

In the context of your question, the presence of magnetic materials in the soil can affect the wave velocity, amplitude, and phase change of the magnetic pulse emitted by the metal detector. This is because magnetic materials can alter the electromagnetic properties of the soil, which in turn can affect the propagation of the wave.

The equation for wave velocity is v = fλ, where v is the velocity, f is the frequency, and λ is the wavelength. In the presence of magnetic materials, the velocity of the wave can change due to changes in the electromagnetic properties of the soil.

The amplitude of the wave can also be affected by the presence of magnetic materials. This is because the magnetic materials can cause the wave to lose energy as it travels through the soil, resulting in a decrease in amplitude. The equation for amplitude is A = A0e^-αx, where A0 is the initial amplitude, α is the attenuation coefficient, and x is the distance traveled by the wave. The attenuation coefficient can change in the presence of magnetic materials, resulting in a decrease in amplitude.

Lastly, the phase change of the wave can also be affected by the presence of magnetic materials. This is because the magnetic materials can cause the wave to change direction or shift in position as it travels through the soil. The equation for phase change is φ = ωt + ϕ, where ω is the angular frequency, t is time, and ϕ is the initial phase. In the presence of magnetic materials, the initial phase can change, resulting in a phase shift in the wave.

To calculate the specific effects of magnetic soils on a pulsed induction metal detector, you will need to consider the specific properties of the soil, such as its magnetic permeability and conductivity. These properties can vary depending on the type and amount of magnetic materials present in the soil. You can use equations and models, such as the ones mentioned in the book you referenced, to calculate the specific effects