How to test the quality of the shielding layer of HDMI HD cable?

The following are some methods to test the quality of the HDMI HD cable shield:

Signal attenuation test: The use of professional signal testing equipment, such as oscilloscopes, signal generators, etc., to measure the attenuation of the HDMI line when transmitting signals. If the shield quality is good,

 the signal attenuation should be small.

Interference test: Place the HDMI cable in an environment with interference sources, such as near other electronic devices, wires, etc., to observe whether the image and sound are interfered with. If the shielding layer is

of good quality, it should be able to effectively reduce interference.

Impedance test: Use an impedance tester to measure the impedance of the HDMI cable. A good HDMI cable with a good shielding layer, and its impedance should be within the specified range.

Appearance inspection: Carefully observe the appearance of the HDMI cable to see whether the shielding layer is tightly wrapped in the core, and whether there is damage, loopholes or loose places.

Comparison test: Compare the HDMI cable to be tested with a known HDMI cable of good quality, and observe whether the quality of the image and sound is different under the same equipment and environment.

Electromagnetic compatibility test: Use professional electromagnetic compatibility test equipment to detect the performance of HDMI cable in electromagnetic environment to see if it meets the relevant standards.

It should be noted that these test methods require professional equipment and certain technical knowledge, if you do not have the relevant conditions, it is recommended to consult a professional or choose a reliable brand 

and product. In addition, when buying an HDMI cable, you can check the product's certification mark and quality assurance to ensure that its quality is reliable.