An extraction channel cleaning company wanted a grease thickness sensor to be developed that would send the data via the internet so that information on the thickness could be accessed remotely. This system consists of two parts: the sensor part and a communications part. This report is on the sensor part, which uses a change in capacitance of an interdigital capacitor, which in turn will change the frequency of the oscillator readout circuit. Initially research was done on the properties of grease to see if it would be a good method to measure the thickness. The results showed that it is possible to use capacitance, but that the permittivity of grease depends on the temperature, so the final design needs a temperature sensor. The prototype that was built was used to measure thicknesses and had quite reasonable results.