An apparatus includes a chassis configured to move back and forth along multiple rails. The apparatus also includes electrical contacts configured to form electrical connections to the rails. The apparatus further includes a power converter/conditioner configured to receive power from the rails via the electrical contacts and to convert the power into a different form and/or condition the power. In addition, the apparatus includes one or more sensors configured to measure at least one characteristic of a material, where the one or more sensors are configured to operate using the power from the power converter/conditioner. The electrical contacts could touch the rails and receive the power directly from the rails. The electrical contacts could also touch rail contacts and receive the power indirectly from the rails via the rail contacts.