# How to determine the dielectric constant of egg tray?

• opticfibering
In summary: I would think that your simulations should show that the attenuation of the RF doesn't depend much on the permittivity and permeability, and would depend a lot on the lossy-ness (resistance) of the material. There is probably a sweet spot in conductivity between high and low that offers the optimum absorption. Be sure to make your cones large enough for whatever frequency you want absorbed.In fact, I wonder if the optimum impedance would match the 377 Ohms of free space. Not sure how to translate that into the volume resistivity target that you should shoot for, but your simulations should show a good starting point.
opticfibering
Hi, can i know how to get the dielectric constant of the egg tray (the one with the paper) beside using dielectric probe technique? is it have same dielectric constant of paper? or it is different? i hope someone can help me.
if the egg tray mix with the carbon or graphite, as i know the graphite dielectric constant for epsilon=12, mue=1, how to calculate the dielectric constant of if both are mix?

I can't imagine a manufacturer would incorporate graphite into his egg trays. Perhaps this is a thought experiment?

i just do the experiment, using egg tray as material. then the egg tray will mix with graphite and fabricate shape. :)

I can't think of any way to determine εr apart from incorporating the material between the plates of a capacitor. If the dielectric is not a good insulator, insulate it from the plates and take this into account.

Thanks NascentOxygen.
here, i would like to do the EM wave absorber using egg tray as material. i need to fabricate using egg tray which i plan to put the egg tray in the water and make it wet and then mix or coated with carbon/graphite.
anyway, εr of the egg tray same with the paper or not?
thanks.

or what is the permittivity of paper egg tray? same as paper?

opticfibering said:
or what is the permittivity of paper egg tray? same as paper?
Well, it would certainly be related to the permittivity of the recycled newsprint that it is made from. But because egg tray material seems to incorporate more air than does the equivalent thickness of paper, I'm hesitant to guess how this pans out.

opticfibering said:
Thanks NascentOxygen.
here, i would like to do the EM wave absorber using egg tray as material. i need to fabricate using egg tray which i plan to put the egg tray in the water and make it wet and then mix or coated with carbon/graphite.
anyway, εr of the egg tray same with the paper or not?
thanks.

Interesting, you are wanting to make your own Anechoic RF Absorbent Material (RAM)?

The dielectric constant will not have a big effect on the absorption characteristics. It is more dependent on the conductivity/losses and the shapes of the cones. The rounded bottoms of the paper egg containers are not a great shape for this, but I don't know of many good alternatives offhand. You might be able to figure out a way to cast some material in the shapes of the cones of typical RAM materials...

And what RF frequencies are you hoping to absorb? The depth of the cones should be on the order of the wavelength that you are trying to absorb.

thank you NascentOxygen.
this means that i need to quick to find the permittivity of the egg tray before i proceed

berkeman said:
Interesting, you are wanting to make your own Anechoic RF Absorbent Material (RAM)?

The dielectric constant will not have a big effect on the absorption characteristics. It is more dependent on the conductivity/losses and the shapes of the cones. The rounded bottoms of the paper egg containers are not a great shape for this, but I don't know of many good alternatives offhand. You might be able to figure out a way to cast some material in the shapes of the cones of typical RAM materials...

And what RF frequencies are you hoping to absorb? The depth of the cones should be on the order of the wavelength that you are trying to absorb.

my project is using egg tray as material to absorb EM wave. in my simulation software, i design the absorber in pyramidal shape then using the egg tray as material. the problem is in the library of the software don't have egg tray material, so i need to load a new material with value of epsilon,ε (permittivity) and mu,μ in there.

opticfibering said:
my project is using egg tray as material to absorb EM wave. in my simulation software, i design the absorber in pyramidal shape then using the egg tray as material. the problem is in the library of the software don't have egg tray material, so i need to load a new material with value of epsilon,ε (permittivity) and mu,μ in there.

I would think that your simulations should show that the attenuation of the RF doesn't depend much on the permittivity and permeability, and would depend a lot on the lossy-ness (resistance) of the material. There is probably a sweet spot in conductivity between high and low that offers the optimum absorption. Be sure to make your cones large enough for whatever frequency you want absorbed.

In fact, I wonder if the optimum impedance would match the 377 Ohms of free space. Not sure how to translate that into the volume resistivity target that you should shoot for, but your simulations should show a curve for absorption versus bulk resistivity that has a maximum at some bulk resistivity value.

And I'm referring to cones that have the same resistivity throughout their volume, not just an egg carton that has some bulk resistivity in the surface of the cups.

ok, thanks. ^^
i will check and try to do regarding to your suggestion/guideline.

Last edited by a moderator:

## 1. How is the dielectric constant of an egg tray determined?

The dielectric constant of an egg tray can be determined by using a specialized instrument called a dielectric constant meter. This device measures the capacitance of the material and uses this information to calculate the dielectric constant.

## 2. What factors can affect the dielectric constant of an egg tray?

The dielectric constant of an egg tray can be affected by the type of material used, the thickness of the tray, and any coatings or additives that may be present. Temperature and moisture can also impact the dielectric constant.

## 3. Can the dielectric constant of an egg tray change over time?

Yes, the dielectric constant of an egg tray can change over time due to factors such as exposure to moisture, temperature fluctuations, and degradation of the material. It is important to regularly test the dielectric constant to ensure accuracy.

## 4. How does the dielectric constant of an egg tray impact its performance?

The dielectric constant of an egg tray is an important factor in determining its insulating properties. A higher dielectric constant can indicate better insulation, while a lower dielectric constant may lead to decreased performance.

## 5. Are there any safety concerns when determining the dielectric constant of an egg tray?

Yes, it is important to take safety precautions when using a dielectric constant meter, as it uses high voltages. It is recommended to follow the manufacturer's instructions and wear appropriate protective gear when conducting these measurements.

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