Applications of PM5 Gen2 in Power Cable Inner Sheath Layer Thickness Measurement

Power cables are used for transmission and distribution of electric energy, and are commonly used in urban underground power grids, power station lines, internal power supply of industrial and mining enterprises, and underwater transmission lines across rivers and seas. In the power lines, the proportion of cables is gradually increasing.

The components of power cables include: conductor, conductor shielding, insulation, insulation shielding, sheath, anti-corrosion asphalt, and outer protective layer. 

The components of power cables include: conductor, conductor shield, insulation, insulation shield, sheath, anti-corrosion asphalt, and outer protective layer.

The materials of power cable sheath can be divided into metallic and non-metallic materials. Metallic materials include copper sheath, aluminum sheath and lead sheath. Non-metallic sheaths include polyethylene, nylon, silicone rubber, TPE and so on. The main role of the inner sheath of the cable is to protect the core wire from water and moisture erosion, to prevent the core wire and insulation from external damage, and has a certain anticorrosion effect. The role of the outer sheath is to protect the insulation layer from external mechanical damage and chemical corrosion, to enhance mechanical strength and improve service life.

We received a power cable with a metal inner sheath from a customer. As you can see from the above, the main function of the inner sheath is to protect the core wire inside, which requires the inner sheath to have good sealing and uniform thickness to meet certain standards.

Manufacturers need to strictly control the thickness of the metal inner sheath during the production process. Measuring its thickness and uniformity using ultrasonic thickness gauges is the primary method of controlling product quality.

We conducted tests using a YUSHI PM5 Gen2 ultrasonic thickness gauge with a single-crystal delay line probe. We obtained clear and stable waveforms and measurements. The thickness of the metal inner sheath is about 3.3mm, and the thickness is uniform. It meets the customer's production process standard requirements.