There's no tricks. But you can change the frequency to the one that is more appropriate for what you are looking for:
FREQUENCY SHIFT
It is used to prevent the device from interfering with other detectors nearby.
To shift the frequency, press the on-off button while holding the (F) button
pressed down. Each time you press the on-off button, a beep will be heard
and/or the device will vibrate and the frequency will shift 1 step. There are 40
steps in frequency shift. The central frequency, which is the factory default,
is indicated by double beeps / vibrations.