A Signal Tester is a device used to measure the strength and quality of signals in various communication systems. It helps technicians and engineers ensure that signals, such as those from cellular networks, Wi-Fi, or radio frequencies, are functioning properly. By analyzing these signals, users can identify issues like interference or weak connections. These testers come in various forms, including handheld devices and software applications. They often display information such as signal strength, frequency, and noise levels, allowing users to troubleshoot problems effectively. Signal testers are essential tools in maintaining reliable communication systems across different industries.