Fluke markets its LVD1 as a non-contact voltage detector (“volt sniffer”), but I’ve found that the bright LED at the end makes a perfectly competent flashlight, too. The LVD1’s voltage-sensor indicator light glows when the unit is close to an AC field, as you’ll see after the jump.
The picture below shows the LVD1 indicating voltage in a lamp cord. It can pick out hot wires several inches away.
For some applications, like crowded junction boxes, you want less sensitivity, and that’s where the Fluke’s bi-color indicator really shines — it flickers blue in the presence of weak fields, turning purple and then finally red as the field intensifies. Anyone working on AC will find it an indispensable tool.
The LVD1 only detects AC fields, so it’s useless for car wiring or anything else DC. It’s also not picky about what frequency it detects, so any changing field will show up — network cables, USB cables, and even fluorescent lights will make the indicator glow. So will cordless and cellular phones, when they’re transmitting! This usually isn’t a problem — holding the light by its clip rather than its body greatly reduces such spurious readings.
The LVD1 runs off a single AAA. In flashlight mode, it gives about three hours of good working light before the output starts to fall off noticeably. It’s good for many more hours of reduced output, adequate for reading but not hiking. When I need hands-free light, I clip it to my hat brim, my shirt collar, or whatever’s handy.
Street pricing is around $25.