Dr. Ahmed G. Abo-Khalil

Electrical Engineering Department

Capacitance probe

Capacitance sensors (or Dielectric sensors) use capacitance to measure the dielectricpermittivity of a surrounding medium. The configuration is like the neutron probe where an access tube made of PVC is installed in the soil. The probe consists of sensing head at fixed depth. The sensing head consists of an oscillator circuit, the frequency is determined by an annular electrode, fringe-effect capacitor, and the dielectric constant of the soil. Each capacitor sensor consists of two metal rings mounted on the circuit board at some distance from the top of the access tube. These rings are a pair of electrodes, which form the plates of the capacitor with the soil acting as the dielectric in between. The plates are connected to an oscillator, consisting of an inductor and a capacitor. The oscillating electrical field is generated between the two rings and extends into the soil medium through the wall of the access tube. The capacitor and the oscillator form a circuit, and changes in dielectric constant of surrounding media are detected by changes in the operating frequency. The capacitance sensors are designed to oscillate in excess of 100 MHz inside the access tube in free air. The output of the sensor is the frequency response of the soil’s capacitance due to its soil moisture level.

Office Hours

No office hours

My Timetable


email: [email protected]

[email protected]

Phone: 2570


Welcome To Faculty of Engineering

Almajmaah University




Links of Interest





Travel Web Sites






ستقام اختبارات الميدتيرم يوم الثلاثاء 26-6-1440

حسب الجدول المعلن بلوحات الاعلان

Summer training

The registration for summer training will start from 5th week of second semester

Academic advising

Class registration week 1

برنامج التجسير

إحصائية الموقع

عدد الصفحات: 2879

البحوث والمحاضرات: 1280

الزيارات: 99610