I was thinking some kind of mylar sheet (craft stores) or the like angled so the meter can lie flat on its back. The camera could then capture the meter reading (albeit upside down) and the moving layout in the background. If going thru a tunnel (if it's wide enough to handle the meter) you'll need a light since the Harbor Freight meter does not have a backlight for its LCD - but then again what do you expect for FREE? Upon reflection (!) Harbor Freight also has freebie LED mini-flashlights which you could mount. So since it appears you already have the video device the budget under a dollar!