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| Breithaupt #3180 "COCLA" Compass Breithaupt & Sohn have been manufacturing magnetic compasses since 1762. The Breithaupt two-circle stratum compass "COCLA" was designed in close cooperation with Prof. Dr. Clar. Thousands of Cocla's are successfully being used by geologists, engineering geologists and rock mechanic engineers worldwide. This instrument is simply the best in the world, and has a reputation as such. Field of Application The modern stratum compass "Cocla" manufactured to the highest standards. It is the ideal instrument for geological, geophysical, mining, tectonic and rock mechanical applications, measuring both the azimuth of dip and angle of dip in one single operation. Breithaupt's knowledge as a traditional compass manufacturer combined with the suggestions of experienced engineering geologists, the Cocla has achieved the ultimate in quality and performance. Made in Germany Visit the Breithaupt Website Stratum compass incl. pouch with belt loop. |  |
| Distinctive advantages - Incorporated eddy current damping, the magnetic needle comes to rest almost instantly (this feature is truly amazing). - Vertical graduation on the cover hinge permits simultaneous measuring of azimuth of dip and angle of dip in one single operation. - Transparent compass bottom (and circular level with hinged mirror) permits measurements & illumination from below the unit. - Permanent locking of magnetic needle by means of lever on the compass corner. - Lateral operation of locking device permitting insertion into narrow rock joints. - Declination adjustment through ±30° - Cover tilting through 260° - Compass circle graduated in 1°. - Sighting device for rapid course aiming. - Cover plate snaps closed protecting the unit. - Cover plate has a friction adjustment screw. - Figures and graduation lines are deeply etched into the housing. - Light weight & small dimensions, yet very rugged. |
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| Description Compass Housing This compass is very solid due to its sturdy housing and cover of light metal, is has proven its robustness with heavy-duty use. The large circular opening in the compass housing contains the graduated circle, the magnetic needle with circular magnet and the damping pot of copper (eddy current damping). At its base the housing is closed by a bottom plate of transparent, unbreakable plastic material. This arrangement permits observation of the compass needle from below, allowing measurements even when the compass is held above the observers head. The top housing is enclosed by glass, on the left side there is a graduated ruler featuring a deeply etched 60 mm graduation. The compass is fitted with an eye-loupe on the front permitting the attachment of a cord to prevent loss/dropping of the instrument. The metal cover is connected to the housing by an adjustable hinge, which serves both as a tracing edge and measuring plate and when closed the cover protects the compass from damage. A spring pin on the compass housing and a notch in the cover serve both as a simple sighting device and as a locking device for the unit. Vertical Circle The cover pivots on an axis on the south side of the compass housing, which is parallel to the plane of the graduated circle. One of the trunnions fixed on the cover bears the vertical circle graduated in quadrants on which the angles of dip can be read against an index line on the compass housing. The vertical circle is graduated in 5° increments and the respective odd 10° marks are numbered. The specific design of the graduation lines and of the index line ensures that angles can be reliably read off to an accuracy of 1°. The quadrants of the vertical circle are distinguished as such by colour (red/black) so that the coordination of the read angle of dip with respect to the azimuth of dip, determined by reading the magnetic needle on the horizontal circle, can be done without danger of mixing them up. Magnetic System The magnetic system is composed of a ring-shaped sinter magnet and a needle. The North of the needle is red and the South is black. The ring-shaped magnet is tightly enclosed in a dampening pot of electrolyte copper and its field flows through the damping pot. A change in the magnetic field resulting from the oscillation of the magnetic needle causes, by induction, an appearance of eddy currents in the damping pot. These currents slow down the movements of the ring-shaped magnet and ensure that the needle quickly comes to rest. Graduated Circle Made of transparent plastic material, this circle is graduated in 1°. The graduation runs counter-clockwise and is clearly numbered every 10°. A declination graduation, complete with a screw drive operating through an angle of ±30°, permits the elimination of the given local declination and thus ensures that the needle records true bearings directly. Locking Device The compass needle may be released by operating a lever on the right-hand corner of the compass housing, either from the right-hand face or from the front face. By simply releasing that lever, the needle is clamped again. Level The circular level located in a recess of the compass housing permits one to level the compass. The circular level can be illuminated and observed from below through a hinged and revolving mirror fitted beneath the circular level. |