Mobile cyanoacrylate chamber with digital control system.
Mobile cyanoacrylate chamber SV-M has automatic heating, air recirculation, humidity support and autonomous cleaning system, has a transparent door for current control over the process of detecting traces.
The camera is specially designed to detect handprints with cyanoacrylate vapors in the field, directly during the inspection of the crime scene.
Working time from one battery charge is not less than 6 hours.
The working space of the chamber is not less than 400x300x200 mm
Theory
Cyanoacrylates interact with the sweat-fat substance of traces in the vapor phase, and the physics of the process is that the cyan group of the glue monomer “strives” for the amino acids contained in the trace, “pulls” the acrylic group, which is the monomer of organic glass, which polymerizes on this trace, making it more prominent, attaches the trace to the trace-receiving surface and colors it white.
In this case, the surface of the trace-receiving object is covered with a layer of whitish plaque (“background”), less intense than the trace itself; the duration of complete polymerization depends on external conditions and ranges from 12 to 24 hours.
Being a physical method of detecting latent fingerprints, the cyanoacrylate method has the following advantages:
— Action in the vapor phase, if used correctly, creates the prerequisites for high-quality detection of both the traces themselves and the details of the structure of papillary patterns, which is very important for poroscopy and edgeoscopy;
— Traces can be repeatedly processed with fingerprint powders and copied onto adhesive films, achieving high-quality fingerprinting. During the polymerization period, particles of fingerprint powder stick to the incompletely polymerized relief surface of the trace, and after the end of polymerization, they are retained on the unevenness of the polymer surface of the trace during processing;
— The detected traces are usually protected from mechanical and many chemical effects, which contributes to the long-term preservation of traces on the carrier object without changing the structure of their details. The detected traces are stored for more than two years; the only change in them is some smoothing of the surface irregularities of papillary lines, in case of repeated contact with the surfaces of other objects;
— Cyanoacrylates have advantages in detecting fingerprints on some trace-bearing surfaces, compared to a number of traditional means. Experiments have yielded good results in detecting and simultaneously fixing fingerprints on glass, plastic, metal surfaces. Traces on polyethylene, linoleum, porous rubber, paper are somewhat worse detected. This method has received particular efficiency, due to its “selectivity”, in detecting fingerprints on weapons and ammunition, the surfaces of which are usually oiled;
— The ability of cyanoacrylots to detect fingerprints of great age (usually up to 30 days, in the practice of the EKU MIA RB there was a case of detecting traces more than two months old; the literature mentions a case of detecting traces more than 220 days old).