What is Dielectric strength: Definition and 19 Discussions

In physics, the term dielectric strength has the following meanings:

for a pure electrically insulating material, the maximum electric field that the material can withstand under ideal conditions without undergoing electrical breakdown and becoming electrically conductive (i.e. without failure of its insulating properties).
For a specific piece of dielectric material and location of electrodes, the minimum applied electric field (i.e. the applied voltage divided by electrode separation distance) that results in breakdown. This is the concept of breakdown voltage.The theoretical dielectric strength of a material is an intrinsic property of the bulk material, and is independent of the configuration of the material or the electrodes with which the field is applied. This "intrinsic dielectric strength" corresponds to what would be measured using pure materials under ideal laboratory conditions. At breakdown, the electric field frees bound electrons. If the applied electric field is sufficiently high, free electrons from background radiation may be accelerated to velocities that can liberate additional electrons by collisions with neutral atoms or molecules, in a process known as avalanche breakdown. Breakdown occurs quite abruptly (typically in nanoseconds), resulting in the formation of an electrically conductive path and a disruptive discharge through the material. In a solid material, a breakdown event severely degrades, or even destroys, its insulating capability.

View More On Wikipedia.org
  1. 1

    High dielectric strength, vacuum compatible glue

    Hi all, I would need an high dielectric strenght glue to fix PTFE or Hostaphan to the vacuum chamber wall in stainless steel, so the glue should be vacuum compatible. Force against the bonding direction would be 50N, so if the glue has already 100N it would be good but I don't think it is an...
  2. 1

    High dielectric strength insulator

    Hello! I would need advice on insulator material I can use for an ion Thomson Parabola spectrometer. I would need to use an insulating sheet of 225x600x1,5mm and a smaller sheet of 100x100x1,5mm I found PBN having an incredible dielctric strength, but seems like it cannot be manufactured in...
  3. HelloCthulhu

    The relationship btw dielectric strength and temperature

    Wiki suggests dielectric strength is temperature dependent, but I've yet to find any math supporting this. I found some math corroborating a relationship between conductivity and temperature, but whether or not there's any causality between conductivity and dielectric strength has eluded me. Any...
  4. HelloCthulhu

    Floating Water Bridge and Dielectric Strength per Volume

    I recently watched a great video demonstrating the floating water bridge experiment: At around 34 sec, you can see an electrostatic discharge before the water bridge forms. I've read that this is due to the electrostatic breakdown of air between the two beakers.This made me curious about the...
  5. CassieFordham

    Layering different dielectric materials to increase breakdown voltage

    This is a general question, not a homework question, and @berkeman said I should post it in the EE forum... I'm trying to get a better understanding of the relationship of dielectric constant (relative permitivity) to dielectric strength (breakdown voltage).I want to know what happens when you...
  6. L

    Dielectric strength and breakdown voltage capacitor

    Homework Statement there's a paper insulated plate capacitor. a.) What should the area of the plates be when the capacitance is 0,1 μF. thickness of the paper in between the plates of the plate capacitor is 0,05mm the relative permittivity of the paper is 2,5 b.) How big of a charge can be...
  7. Robsta

    Investigating the water-ice electret

    Hello all, I'm going to investigate the properties water when frozen in a strong electric field for a product I'm designing. A strong field will align the polar water molecules, and then they will freeze. I'm planning to create this strong field with a car battery attached to two parallel...
  8. I

    Electric field using dielectric constant

    Homework Statement What is the magnitude of the electric field due to a 6.0 x 10-9 C charge at a point located 0.025m from the charge? The charge and the point in question are located underwater (κ(water) = 80). Homework Equations I know that E = magnitude of electric field = kq/r2, where k =...
  9. P

    Can Different Electrodes Affect Air's Dielectric Strength Values?

    Hi, Am I correct in thinking that for a medium such as air, the dielectric strength is a property of the material and as such has a single value for that material? The reason I ask is because I have been testing the breakdown of air between different types of electrodes and because the...
  10. M

    Calculating Dielectric Strength between plates

    I know that I should do my homework, but I lost all my notes because of the flood brought by "Sendong" a storm in the Philippines. I just need the equations to be used to solve the problem that was given to us. So here it is: A parallel plate capacitor has a capacitance of 7MF when filled...
  11. G

    Increase dielectric strength of a cylindrical capacitor

    Homework Statement You have a co-axial cylindrical capacitor placed in vacuum. The two co-axial cylinder tubes are made of copper. The outside tube radius a1 and inside tube radius a2, with overlapping length L; both tubes have a thickness of t. Say, the capacitor was designed to withstand 5...
  12. C

    High dielectric strength insulator

    Hi, Does anyone know which insulator will have very high dielectric strength at room temperature? The dielectric strength is the electric filed strength of a material can resist before it breakdown.
  13. F

    Frequency Dependence of Dielectric Strength

    Does anyone know what the relation between frequency and dielectric strength is? I'm mainly concerned with the dielectric strength of air in the High Frequency and Very High Frequency Ranges (3MHz - 300MHz). Thanks.
  14. T

    Calculate Dielectric Strength Breakdown Voltage

    I know it has to do something with the Breakdown voltage but I've looked everywhere on my book and i have no idea how to calculate it.
  15. T

    Dielectric Strength Formula: Find it Here!

    What's the formula to calculate it, I've looked everywhere.
  16. F

    Dielectric Strength: Safe to Use Across 240v/415v Terminals?

    I understand that Dielectric Strength relates to the point where a compound breaks down under electrical load. Please correct me if I have it wrong. I want to now if an RTV compound (with Dielectric Strength of approx 500 volts/mm) is safe to use across 240v or 415v terminals that are 3-5mm...
  17. E

    Dielectric Strength Of Liquids: looking for data

    Hello all of you! I'm looking for reliable data about the dielectric strength (=breakdown field) of liquid insulators with a high permittivity and a low viscosity and not too dangerous. Examples of such liquids: - Ethylene glycol carbonate. Propylene glycol carbonate. Maybe the oxalates...
  18. J

    How to find the Dielectric Strength

    Hello, everyone! I have a question, and i don't know how to solve it... They ask me for the dielectric strength! How do i find it?
  19. K

    Is My Calculation of the Radius in a Dielectric Strength Problem Correct?

    Dielectric Strength problem. Please Help! :( If anyone can let me know if I went about this right, I'd appreciate it, as well as any advice. The dielectric strength of an insulating material is the maximum electric field strength to which the material can be subjected without electrical...