The differences in spectrometers designed for use in the lab from those that are deployed at-site, in fi eld locations are rather profound. As an example, laboratory instruments are designed to work on a planar horizontal surface — the bench top — whereas handheld spectrometers are often called upon to operate in virtually every physical position. Interferometers used in lab FTIR spectrometers ...

The measurement of the mutual impedance of thin circular loop antennas on an N-layered conducting medium at high frequency is calculated. The horizontal, vertical coplanar, perpendicular and vertical coaxial loop antennas have been presented, the comparison between them and the numerical results have been calculated. The displacement currents in free space and in the conducting medium are taken...