I bought shielded RJ45 Connectors, cables and RJ45 couplers, how do I verify their shielding performance?
In my opinion, anything wrapped in a metal casing is usually shielded. However, I’m not quite sure how to verify its shielding. I would also like to know more about this issue. 
Suggest some ways to confirm
Visual Inspection: Start with visually examining the connectors, cables, and couplers to ensure they are appropriately shielded. Check for any visible gaps or damage in the shielding materials.
Resistance Measurement: Measure the resistance between the shielding connections of the connectors, cables, and couplers using a multimeter. A low resistance reading indicates an excellent electrical connection and effective shielding.
Signal Integrity Testing: Connect the shielded cables to your desired equipment or network. Perform data transfer tests, such as transmitting large files or monitoring network performance. Monitor the signal quality, interference, or noise levels. If the shielding is effective, you should observe minimal signal degradation or interference.
Electromagnetic Interference (EMI) Testing: If you can access the necessary equipment, perform EMI testing. This involves placing the shielded cables and connectors in an environment with known sources of electromagnetic interference. Use an EMI receiver or spectrum analyzer to measure the reduction of interference when shielded cables are used compared to unshielded ones.
You can test this using cable testing equipment specifically designed to test shielding effectiveness.
A DC continuity test is a helpful method. You may need to buy a fluke tester but it is expensive. If you don’t often install the network, you can also rent one.
The most straightforward thing to do is to check your internet speed
Is there any alternative tool to the Fluke tester? Fluke is too expensive and I don’t know where to rent it.
Well, if you’re seeking a professional tester, FLUKE is your first choice.