I. Audio detector
1. Acoustic audio detector
The target is detected by acquiring weak sound waves propagating in the air and amplifying the signals.
2. Vibration wave audio detector
The vibration probe picks up and amplifies the vibration wave from the ground to detect the target.
The same characteristics of the two are: low price, relatively simple and easy to use.
Limitations: certain holes and cracks are needed in the field to reach the testing equipment; Or only suitable for shallow and large space exploration; In case of rain or fire, it will be disturbed by the environment.
Second, the video detector
Using visible light or invisible light, it is photographed by CCD sensor and transmitted to the display screen for imaging.
Video visualization, intuitive, simple, easy to use and cheap.
Generally, cables are needed to transmit audio signals, or gaps and holes.
Third, the radar wave life detector
Radar antennas emit electromagnetic waves directionally and intensively, which can penetrate concrete walls and rubble. It will reflect and change after contact with the human body. Because this change is influenced by human body activity, breathing and even heartbeat activity, the reflected electromagnetic waves are received by the receiver, and after filtering out the background interference, some unique spectra are analyzed and processed by computer software and displayed on the display screen.
It has the characteristics of convenient carrying, fast moving speed, no contact with objects, no need to enter through holes and gaps, etc., and can detect trapped people under the condition of being isolated and covered by various substances.
Radar electromagnetic waves can't penetrate the solid metal shielding wall, and people trapped behind the wall are detected.
Life detection radar is mainly composed of wireless detection transmitter and PDA.
The wireless detection transmitter first emits radar waves, which can penetrate ordinary building walls, gravel and other materials and reach the measured target 6 meters away. The movement of the target or the heartbeat of breathing will change the radar wave to some extent, and the changed radar wave will be transmitted back to PDA through the antenna. Through the data processing of professional software in the computer, the corresponding waveform diagram and signal display are obtained, so as to judge whether there are survivors in the tested area.
When operating the detection radar, ensure that the distance between PDA and wireless detection transmitter is within the range of 1.5- 15m, and there is no other suspicious movement within the range of 6. 1m from the detector antenna. The equipment can usually complete the search in the effective space within 3 minutes, and further locate the trapped people.