电烤箱红外辐射法显现纸张表面汗潜手印

Visualization of Sweat Latent Fingerprints on Paper Surfaces by Way of Infrared Radiation from Electric Oven

本文以红外辐射法显现纸张表面汗潜手印原理为基础,结合电烤箱的结构和工作原理,实验研究了用"美的T1-L101B电烤箱"作为红外辐射源显现纸张表面汗潜手印的可行性及最佳辐射条件、方法适用的手印遗留时间范围等。研究结果表明,用电烤箱作为红外辐射源可以显现不同种类纸张表面的汗潜手印,用该法显现纸张表面汗潜手印时,打印纸表面汗潜手印致荧光最佳辐射条件为160℃、14s,致碳化最佳辐射条件为160℃,5min;报纸表面汗潜手印致荧光最佳辐射条件为160℃、45s,致碳化最佳辐射条件为160℃、9min;牛皮纸表面汗潜手印致荧光最佳辐射条件为160℃、19s,致碳化最佳辐射条件为160℃、15min;画报纸表面汗潜手印致荧光最佳辐射条件为160℃、42s,致碳化最佳辐射条件为160℃、19min;该方法对纸张上遗留时间为15d以内的(本实验所涉及的)汗潜手印均显现效果较好。该方法实用、经济、简单、有效、可靠、易于推广,是手印显现的新途径,对提高现场手印显出率有支持作用。

Sweat latent fingerprints can be developed on paper surfaces by way of infrared radiation.This article describes an experiment that used“Meidi T1-L101B electric oven”as the infrared radiation source to conduct such a test,exploring the optimal radiation conditions and the time ranges of keeping fingerprints.The experimental result shows that the electric oven can function as an infrared radiation source to develop sweat latent fingerprints on different paper surfaces.Although the optimal temperature is160℃(causing the fluorescence to emit)for all kinds of paper to both develop sweat latent fingerprints on the relevant surface and be coked,yet the most appropriate time is influenced with the kind of paper to achieve either the good fingerprint-visualizing result or the paper coking,thus the printing paper requires14seconds for fingerprint-visualizing and5minutes for coking,and such the above two time for the newspaper at45seconds and9minutes;for kraft-paper at19seconds and15minutes;for magazine-used paper at42seconds and19minutes.The experiment also demonstrated that a good development can be obtained for the sweat latent fingerprints which are left on paper within15days.The method established here is practical,economical,simple,effective,reliable and easily applicable,offering a new way to develop fingerprints and a reliable support for on-site visualization of fingerprint at the crime scene.