The FKP is applicable to various lab and field applications as it measures the contact potential difference between the probe and a conductive sample

The FKP can provide direct and indirect detection of the incipient phase of hidden corrosion

Applications include include quality control of bare and coated metals, inspection of hidden corrosion under coating, external inspection of internal corrosion in e.g. pipes and vessels, corrosion in reinforced steel in concrete, etc. 




The compact size and ergonomic design with batteries in the lid enables hand-held operation for many hours of operation 




The FKP communicates wirelessly with a mobile device. All FKP data can be stored on the device and accessed remotely, via a remote server


The rotating sensor and a built-in reference in the sensor housing enable automated self calibration of each measurement point


The FKP can be operated in the field by hand or installed on a crawler. For lab use, the FKP can be interconnected on a XYZ scanning stage 


Lord Kelvin, also known as W. Thomson introduced the Kelvin probe technique in the 19th century. For decades, the Kelvin probe technique has been used to measure work functions of materials. Around 1990, the group with Stratmann et al. Max Planck Institute für Eisenforschung (MPIE) were the first who introduced Skanning Kelvin Probe (SKP) to corrosion science. 

The FKP resembles to some extent the traditional Scanning Kelvin Probe (SKP) technology which is frequently deployed in laboratories to measure surfaces and to detect onset and propagation of corrosion on small samples. Basically; a Kelvin probe and the sample-surface forms a simple parallel-plate capacitor.


Both the FKP and the SKP derives the electrode potential of a test object from the Volta potential difference established between the test object and the probe by varying the capacitance between the two materials to generate a displacement current. Measurement of the discharge current when the distance between probe and sample is varied was first introduced by Lord Kelvin and this classical set-up is in fact one of the oldest techniques for measuring the work functions of materials.


However, the FKP construction and operation are quite different from the SKP. One obvious difference between FKP and SKP is that the SKP vibrates a thin needle while the FKP is based on a rotating sensor. Another difference is the hand-held design of the FKP that implies wireless communcation, integrated electronics and battery operation. This extends Kelvin Probe applications from small samples in the lab to larger samples in the lab and field.

INDIKEL owns all IPR to the Field Kelvin Probe (FKP) Technology

Inventors for the FKP patents are Eugen Florin Turcu and Michael Rohwerder

The encapsulation is designed by Inventas

© Copyright: INDIKEL AS