After using the wireless jammer, if you want to test its shielding effect, you can usually see whether the mobile phone displays a signal. If it is not displayed, it indicates that the shielding is successful. Another case is that the mobile phone still displays the signal, which may be caused by the following reasons.

1. There is no signal near the wireless jammer. But standing in the distance, the mobile phone can connect the phone normally. This indicates that there may be a base station or signal amplification in the location, which depends on the signal strength of the site. Where the signal is strong, the shielding distance of the wireless jammer will be shortened, and when the signal is weak, the shielding distance will be far. It shows that if the current wireless jammer cannot meet the on-site shielding requirements, some high-power shielding equipment can be added.

2. The mobile phone is in a critical state. Generally, this happens to the mobile phone with strong anti-interference ability and high sensitivity.