Plane table

A measuring table is a ( historical ) Work equipment of geodesics or topographers in the site survey for the production of cadastral and land plans by the graphic / drawing method. It is made of wood with exactly planar and distortion- free surface and can level up by dragonfly. The size is typically 40 × 40-60 × 60 cm.

Johannes Praetorius is considered the inventor of the measurement table, the so-called Mensel, this is proved by his student Daniel Schwenter.

The plane table was screwed for the purpose of angle measurement on a three-legged stand test, the one situated centrally over a survey point. On the wooden plate the recording sheet, a page or a card has to be updated (also called mapping ) attached. The orientation of the measuring table top was made according to the purpose of the recording to the north, south or a preferred direction in the landscape (eg Talverlauf ). For alignment by geographic north see orientation (map).

The point (usually a survey point ) above the measuring table was developed, it was with the Lotgabel or any other suitable means on the recording sheet ( usually with a Kartiernadel ) through a puncture, the transmitted " pricking out " on the receiver sheet.

Most important tool on the measuring table were:

• A Lotgabel to position mapping to a selected reference point to the nearest point of the table
• Exactly on the marked with the Kartiernadel measuring point - - to measure directions to points of detail in the terrain and draw in the freely moving alidade or alidade
• A compass ( Präzisionspeilkompass )
• General character device, such as pencil, eraser, set squares, scales, rulers, stencils, carrier, etc.
• Kartiernadel

After completing the measurements, the mapping with the recorded detail and border points at the office was drawn to terms. The stage is also eponymous for the Messtischblatt. For small Operaten sometimes initially unknown locations were used instead of measurement points whose relative position was determined by graphical triangulation.

Similar instruments for simple surveys are used Chance today. The graphical method has the advantage to get along in the small area without calculations.