Density gauges are used where automatic control of a liquid, powder or solid is important, for example, in detergent manufacture. Tobacco companies are among the biggest users of radioisotope density gauges, which are used to check the amount of tobacco that is packed into each cigarette. Very little maintenance of the isotope source is necessary. Radiography Radioisotopes which emit gamma rays which can be used to check welds of new gas and oil pipeline systems, with the radioactive source being placed inside the pipe and the film outside the welds. This is more convenient than employing X-ray equipment.
Some radioisotopes emit a lot of energy as they decay.
Such energy can be harnessed for heart pacemakers and to power navigation beacons and satellites. The decay heat of plutonium-238 has powered many US space vehicles and enabled Voyager to send back pictures of distant planets. Pu-238 powers the Cassini space probe on its way to Saturn. Dating Analysis of radioisotopes is of vital importance in determining the age of rocks and other materials that are of interest to geologists, anthropologists and archaeologists. From the moment we get up in the morning, until we go to sleep, we benefit unknowingly from many ingenious applications of radioisotopes and radiation.