An automatic
powder supply and trace detection device for extracting fingerprints by means of crime scene
powder method and
powder supply method thereof; an
air pump (3) is in electrical communication with a battery (1), and an air outlet end of the
air pump (3) is in communication with a powder
bottle (7); an ultra-microporous fluidised
bed (10) is installed inside the powder
bottle (7), the trace detection powder in the powder
bottle (7) being accommodated above the ultra-microporous fluidised
bed (10); pressurised air outputted by the
air pump (3) passes through the ultra-microporous fluidised
bed (10) from below the ultra-microporous fluidised bed (10), forming a plurality of independent air streams acting on the bottom of the trace powder, and producing a
mixed gas on the surface of the trace detection powder; one end of an outer shell (22) is provided with a
nozzle (20) having a
nozzle opening, and a
brush head (13) surrounds the
nozzle opening, a
mixed gas pipe (8) being hermetically connected to the nozzle opening being arranged inside the powder bottle (7), the
mixed gas produced in the powder bottle (7) being conveyed to the
brush head (13) of the nozzle opening by means of the mixed gas
pipe (8), and the trace detection powder in the mixed gas coming into contact with a
fingerprint trace and attaching to the surface of the
fingerprint trace to form a clear image. The automatic powder supply and trace detection device improves the
working environment of police officers, reduces the amount of powder used, and increases the efficiency of sampling work.