Why can't you detect the camera with an electromagnetic instrument？

The reasons why an electromagnetic detector may fail to detect a camera could include the following:

1. The camera is turned off or not transmitting a signal. Electromagnetic detectors primarily detect electromagnetic signals. If the camera is turned off or not transmitting any signal, the detector may not be able to detect it.

2. The camera's signal frequency is outside the detection range. Different detectors have varying frequency ranges. If the camera's signal frequency is outside the detector's range, it will not be detectable.

3. The signal strength is too weak. If the camera's signal is too weak or is being shielded, the detector may not be able to capture it.

4. Insufficient sensitivity of the detector
Low-quality or aging detectors may have reduced sensitivity and may not be able to detect weak electromagnetic signals.

5. The camera uses wired transmission
Electromagnetic detectors are primarily used to detect wireless signals. If the camera is using wired transmission, the detector will not be able to detect it.

6. Environmental interference
If there are other electromagnetic signals in the surrounding environment, the detector may have difficulty accurately identifying the camera's signal.

7. High concealment of the camera
Some cameras are specially designed with signal shielding or camouflage, making detection more difficult.

8. Improper operation
Improper use of the detector or incorrect parameter settings may also result in the failure to detect the camera.

Therefore, even when using an electromagnetic detector, it may not be possible to find all cameras. It is recommended to use a combination of methods for comprehensive detection.