In:
Review of Scientific Instruments, AIP Publishing, Vol. 60, No. 1 ( 1989-01-01), p. 96-103
Abstract:
A single-mode microwave heating and dielectric measurement technique has been developed. The single- and swept-frequency methods were used to simultaneously heat the material and measure its complex permittivity in this single-mode technique. A cylindrical cavity and Nylon 66 rods were used in this study. The cavity was always resonated in the TM012-mode at 2.45 GHz. The measured changes in the resonant frequency and cavity Q factor of the cavity with and without the sample were related to complex permittivity of the sample using material-cavity perturbation. Temperature measurement was made using a fluoroptic thermometer. On-line measurements of complex permittivity and temperature were made during single- and swept-frequency microwave heating of the sample. Complex permittivity of Nylon 66 as a function of temperature using the single-frequency method was compared to that using the conventional swept-frequency method during microwave heating. It shows that dielectric measurements using the single- and swept-frequency methods are repeatable and consistent. However, the resolution in resonant frequency shifts and cavity Q factor measurements is higher in the single-frequency method. The measurement errors for permittivity and dielectric loss factor are less than ±4% and ±10% for the single-frequency method and less than ±5% and ±15% for the swept-frequency method. Therefore, the single-frequency method is more accurate than the swept-frequency method.
Type of Medium:
Online Resource
ISSN:
0034-6748
,
1089-7623
Language:
English
Publisher:
AIP Publishing
Publication Date:
1989
detail.hit.zdb_id:
209865-9
detail.hit.zdb_id:
1472905-2
SSG:
11
Permalink
