Comments on “Complex Dielectric Measurements of Forest Fire Ash at X-Band Frequencies” [Sep 11 859-863]

In the above letter, the authors investigate and present dielectric measurements of powdered forest fire ash using the Nicholson–Ross–Weir method within a WR-90 waveguide (X-band 8–12 GHz). However, some errors have been found, which are clarified in this letter.