The cross section of the standard coaxial cable is very round, and the outer conductor of the cable and the aluminum plate are attached to the outer surface of the insulating medium. The rounder the outer surface of the medium, the smaller the gap between the aluminum foil and its outer surface, and the smaller the gap is, the larger the gap is. Practice has proved that the smaller the gap, the better the performance of the cable. In addition, the large gap air easily invades the shielding layer and affects the service life of the cable.
2. Measure the consistency of the insulating medium of the coaxial cable
The fluctuation of the dielectric diameter of the coaxial cable mainly affects the echo coefficient of the cable. This inspection can cut out the insulation medium of a cable. Use a micrometer to carefully check the outer diameter of each point to see if it is consistent.
3. Measuring the woven mesh of the coaxial cable
The textile cable of the coaxial cable plays an important role in the shielding performance of the coaxial cable, and is also the return line of the power supply in the centralized power supply cable TV line. Therefore, the coaxial cable quality inspection must check whether the textile mesh is tight and flat. The utility model is to cut the outer sheath of the coaxial cable, cut a small section of the coaxial cable woven mesh, and identify the number of the woven mesh. If the value is consistent with the given index value, the single textile wire is measured by the spiral micrometer. At the same price, the coarser the wire diameter, the better the quality.
4, Check the quality of aluminum foil
The important shielding function in the coaxial cable is aluminum foil, which plays an important role in preventing external open circuit signal interference and cable television signal condensation. Therefore, the quality of the aluminum foil should be checked for the new coaxial cable. First, cut off the jacket layer and observe whether the surface of the braided wire and aluminum foil layer maintains good luster. Secondly, take a cable and tightly wrap it around the small metal shaft, straighten and reverse the winding, repeat several times, and then cut it. The cable sheath layer can be seen whether the aluminum foil is cracked or not. A small piece of aluminum foil can be cut and twisted repeatedly in the hand. After repeated twisting and stretching, it is still not broken, and the toughness is cohesive, otherwise it is a defective product. .
5, Check the tightness of the outer sheath
The high-quality coaxial cable outer sheath is tightly packed, which can reduce the gap in the shielding layer, prevent the air from entering and cause oxidation, and prevent the relative sliding of the shielding layer from causing the electrical performance to drift. However, if the extrusion is too tight, the peeling is inconvenient. Increase the difficulty of construction. The inspection method is to take a cable of 1 m length and remove the sheath at the end, so that the core cannot be pulled out with force.
6, Check the cable into a ring shape
Cable looping is not only an aesthetic issue. And it is also a quality issue. The cable is flattened in a circle, and the cables are kept on the same concentric plane. The cable and the cable are in parallel contact with each other in an arc, which can reduce the mutual stress of the cables, and the stacking is not easily deformed and damaged. Therefore, it is not taken lightly when accepting the cable quality.