Moisture content of wheat, Triticum aestivum L., is expressed as a fun
ction of the ratio of microwave attenuation and phase shift, measured
at 16.8 GHz, and grain temperature. Validation of the calibration equa
tion indicated that moisture content was obtained with an uncertainty
less than +/-0.45% moisture at the 95% confidence level, independent o
f density variation, at temperatures from -1 degrees C to 42 degrees C
, and moisture contents from 10% to 19%. Moisture determination does n
ot depend on the layer thickness of the wheat nor its bulk density. No
differences between two wheat cultivars were observed in the measurem
ent data.