Heating with microwaves
Microwaves penetrates food products and the heating extends within the entire product.
Packaging materials such as glass, ceramics and most thermoplastic materials allows microwaves to pass with little or no absorption.
The relation wavelength, frequency and velocity of electromagnetic waves:
λ = c / f (1)
λ = wavelength (m)
c = speed of light (3 108 m/s)
f = frequency (Hz, 1/s)
Permitted frequencies for microwave ovens
- 915 +- 13 Mhz
- 2450 +- 50 Mhz
The wavelengths can be calculated as
λ1 = (3 108 m/s) / (915 106 1/s)
= 0.328 (m)
λ2 = (3 108 m/s) / (2450 106 1/s)
= 0.122 (m)