Uniplanar-capacitance measuring plate and capacitive detection unit

The invention provides a uniplanar-capacitance measuring plate, which is used for detecting a dielectric constant of a to-be-measured material in a measurement electric field area of the measuring plate and outputting a corresponding capacitance signal in a non-contact manner. The measuring plate comprises a circuit board including a front end face and a reverse end face. The front end face is provided with an annular emission electrode and an annular reception electrode corresponding to the emission electrode, wherein a gap is formed between the emission electrode and the reception electrode. During a process of detecting water in the material, a measurement electric field is generated between the two electrodes, and the electric field line of the measurement electric field starts from the emission electrode and returns to the reception electrode. Since the two electrodes of the measuring plate are in no contact with the to-be-measured material in the process of detecting a water content in the material, the water contents of materials with different water contents can be detected. The measuring plate has characteristics of simple structure, high detection precision, and wide application range. The invention further relates to a capacitive detection unit adopting the measuring plate.