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The Freiberger and Freiberger with mirror are identical compasses just with and without a mirror respectively, with the Compass and Mirror configuration being the most popular. The Freiberger is the original structural geology compass and was built according to the specifications of a famous geologist known as Dr Eberhard Clar. Freiberger is the company that took the contract to make the first ever geologist compass and they’ve been making them the same way in Germany ever since. This compass design allows a geologist to take a reading of direction and azimuth of dip at the same time.
So if your a geologist and your chasing a structural geologist compass you usually have the option of :
- Freiberger (with or without mirror)
- Krant Compass
- Breithaupt Gekom Basic
- Brunton 5010 Geo Pocket Transit
The key features that make a compass a structural geologists compass are the level bubble, an adjustable and locking dip needle and on the side of the compass there is a vertical circle attached to the lid that allows them to measure azimuth of dip.
For interested parties this Wikipedia page has some good photos and text to explain it – https://en.wikipedia.org/wiki/Geological_compass
COMP-112 & COMP-113 Features
- Permanent locking of the magnetic system - can be released during measurement by depressing the push-button and should be used for shortening the setting time
- Lockable inclinometer for inclination measurements of high accuracy
- Operates -30oC - +50oC.
- Ground magnetic needle placed on edge.
- Easy adjustment of the graduated circle - for each measuring technique and for setting declination values of any magnitude
- Colour coding on circle of altitude and magnetic needle (according to Clar) - unambiguous determination of the direction of dip of geological formations
- Circular spirit level for levelling, lateral glass tube for measurement at points of difficult access
- Dip measuring plate
- Horizontal level bubble for measuring where access is difficult.
- Circular level bubble for simple levelling.
- Dust & water resistant.
COMP-112 & COMP-113 Applications
- Can be used for route surveying, for the survey of natural and artificial openings above and below ground
- Surveying of open pit or underground workings
- Transfer of geological data onto maps and plans
- Staking out of claims and sites
- General field-geological work
- Special structural-geological, deposit-tectonic, and engineering-geological rock mechanical work
- Rock work as well as moderate-accuracy surveying
Unique COMP-113 Features
- Features mirror on the internal surface of the lid and a front & back sight.
Freiberg Compasses Chemical Composition
Si: 0.7-1.3
Fe: 0.50
Cu: 0.10
Mn: 0.40-1.0
Mg: 0.6-1.2
Cr: 0.25
Ni: 0
Zn: 0
Ubrige: 0.15
Ti: 0.10
Al: Balance
