Now, there are schools that test and analyze hand-held metal detectors in the examination room to detect which "targets" will make a sharp buzz about its buzzers, or the vibrators will vibrate.
The research activity is to slowly approach the detection ring of the metal detector. When the detector emits a beep, the distance between the detected object and the center of the detection ring of the metal detector is measured with a ruler. Obviously, the farther the object can be detected, the more easily it is detected, ie the more sensitive the instrument is. In order to ensure the accuracy of the experimental results and the reliability of the data, we repeated all experiments for 3 times and averaged the data. If there are extreme values, we discarded them.
1, the relationship with the elemental form
Copper and iron are metals that are widely used in daily life. Therefore, we first detected and compared the simple substance (solids), solid compounds, and solution compounds of these two metals.
The experimental results show that the Suzhou AOTUNG AT600S hand-held metal detector can detect "metal" should only refer to the free (ie, elemental) metal, rather than the general "metal element", when the metal is converted to a compound, that is unable to Was detected.
2, the relationship with the shape of the metal
Metals present in elemental form have different shapes, such as fine powders, large particles, flakes, and blocks. First, the metal powder most commonly used in the experiment was tiled on paper to detect it. The results are as follows:
The metal powder could not be detected, and the powder particles of these metals were magnified and tested. As a result, both the zinc particles and the nails appeared to be “shaped”.
Film metal, sheet metal, and bulk metal were detected. The experimental objects were aluminum foil, silver foil, zinc foil, copper foil, iron block, copper block and so on. Among them, the silver foil comes from the “spectacular reaction”, and we directly probed the thin silver foil-coated test tube attached to the inner wall. The results showed that these metals, including thin silver foils, did not have any “leakage”.
It is worth mentioning that the metal detector can "detect" the presence of silver metal on the inner wall through the glass wall of the test tube, which also indicates that the detection of the metal does not necessarily require the metal to be completely exposed. It is also based on this that metal detectors can be widely used to detect some of the more concealed contraband items.
3, the relationship with the quality of metal
Since zinc particles are granular, it is convenient to take different amounts of solid samples, so zinc particles are selected as the research object. To control the variables, different quality zinc pellets were loaded into 3 tubes of the same size and were probed vertically towards the bottom of the tubes. This ensures at least that the cross-sectional area of the detected objects is the same.
From this, it can be seen that the greater the metal quality, the easier it is to detect; conversely, the metal quality is too small and may not be detected.
The school's investigation of the series of experiments has led to the conclusion that the metal detector is an instrument capable of detecting metal elements only. The detection effect of metal on the metal is related to the shape and total mass of the metal.