Abstract: A system for determining the energy and volume delivered by a flowing natural gas carried within a pipeline based on BTU content analysis of the natural gas using a micro-miniature gas chromatograph. By monitoring key parameters of the flowing natural gas, such as temperature, pressure, flow rate, and BTU content, the system 110 accurately determines the total energy and total volume delivered by the flowing natural gas over a programmable duration of time. Micro-miniature fabrication of the gas chromatograph imparts important advantages to the system 110, including small size, modular design, low power consumption, fast BTU analysis times, and low consumption of consumable carrier and reference gases.

Abstract: An arrangement for automatically connecting a first battery either in series with or in parallel to a second battery in order to maintain a minimum output terminal voltage including a voltage sensor which detects when the operating voltage of the batteries falls below a first threshold. When this occurs, switching devices are activated to convert the parallel connection of batteries into a series connection, thereby doubling the operating voltage. When the battery voltage rises above a second threshold which is at least twice the first threshold, the switching means are activated to reconnect the batteries in parallel.