Capacitance measurement, FFT analysis and SRL prediction as well as bare patch detection in one device

The transmission of high frequency, analog or digital signals at minimum loss for the signal amplitude is an essential quality feature for all LAN, coaxial, telephone or RF cables. In this context, the measurement of the capacitance during cable production is of crucial importance. The capacitance determines the impedance of the cable for the specified frequency range and thus, the quality of the cable significantly. Thanks to the multi-zone electrode SIKORA’s CAPACITANCE 2000 is predestined for a reliable capacitance measurement.

The CAPACITANCE 2000 is installed in the cooling trough and measures online the capacitance of the wire insulation and reliably detects bare patches. Additionally, the system recognizes periodical capacitance changes and determines the Structural Return Loss (SRL).

The quality control is realized by the combination of a short and a long measuring electrode which are integrated into one measuring tube. The short measuring electrode with a length of 10 mm (.39”) identifies periodical capacitance variations with high spatial resolution by means of Fast Fourier Transformation (FFT). From the FFT data, the SRL is determined and gives information about the expected attenuation of the RF signal during data transmission. The long measuring electrode of 125 mm (4.92”) measures with high precision the average capacitance value.

In combination with a diameter measuring device of the LASER Series 2000/6000 or the CENTERVIEW 8000, the CAPACITANCE 2000 also offers a control of the Capacitance and the Diameter (CD-Control). The CD-Control assures that the capacitance and the diameter comply with the requirements. This is achieved by an automatic adjustment of the cooling trough and by the control of the line speed. Both influenced quantities are controlled by the processor system ECOCONTROL 6000.