Abstract: The present invention is directed to a means for compensating for pressure changes in sensing devices. To assure accurate measurements with sensing devices immersed in a medium, it is necessary to have external and internal pressures preferably the same or very close. This invention provides pressure compensation through the use of at least one but preferably a plurality of passages communicating the exterior to the interior of the cell. The passage preferably but not necessarily is so designed as to provide an inner portion of the passage with a greater dimension than the remainder. In the greater dimensioned portion of the passage is positioned a substantially non-tensioned membrane so as to provide a separation or barrier between the interior and exterior of the cell.