Abstract: The invention relates to a sensor device for measuring attitude, acceleration or gravitational field and its gradient components. The device includes a spherical cavity (3) which contains a sensor substance in the form of a fluid or some other inertial material having fluidic properties. The cavity (3) is provided with measuring sensors or measuring electrodes (−x, +x; −y, +y; −z, +z) for three different coordinate axes x, y, z, all of said sensors responding to said common inertial mass which fills the cavity (3). Such assembled single compact measuring device can be used for determining any of the said quantities 3-dimensionally.

Abstract: A sound source arrangement for use in carrying out a seismic survey comprises flexible structural modules connected together end-to-end to form an elongated flexible structure of substantially uniform exterior cross-sectional shape and size. The elongated flexible structure can be stored on a reeling unit and may be unwound from the reeling unit at a survey location and wound back onto the reeling unit without disconnecting the modules from one another. At least one of the flexible modules is an air gun module which includes a device for producing sound impulses.