The present generation of portable electronic explosives detectors, however, can only detect a limited range of organonitrate explosives such as ethylene glycol dinitrate, nitroglycerin, and in some cases, trinitrotoluene. Most instruments are not sensitive or versatile enough to detect inorganic nitrate explosives or the lower vapor pressure organonitrate explosives. In practice, this means that the portable detectors are useful for indicating the presence of dynamite, but they will most likely fail to warn of pipe bombs or plastic explosives. It is concluded that commercially available portable explosives detectors do not have the capabilities to replace canine and visual/hand searches as the primary methods of explosives detection. On the other hand, studies have indicated that portable electronic explosives vapor detectors do improve the efficiency of canine and visual/hand searches for concealed explosives. This equipment can be used effectively for the corroboration and identification of suspected explosives and areas that are inaccessible to canines. 30 references, appendix.