DOCTER NOBILEM 7 x 50 NAVIDOC - Manual (Page 12)

The scale on the graticule plate is arranged in such a manner that the distance between
two large lines (an interval) corresponds to an object size of 10 m in 1000 m. With the
aid of the scale it is possible with a known size of the object to estimate its distance.
Here the following calculation formula must be used.
With a known distance of the object it is possible to determine its size according to the
following formula:
NOBILEM Navidoc nautical binoculars
The NOBILEM Navidoc was designed specially for use at sea and is optionally
equipped ex works with graticule plate or graticule plate and compass. The use of the
graticule plate with the Navidoc is similar to the method described above.
Additionally to the graticule plate the Navidoc can be equipped at the works with a high
performance magnetic compass (8) with 360° Rose (right ocular side). The compass
possesses a 1° division and is mirrored in a special graticule plate. In this way an exact
determination of the points of the compass can be undertaken.
The points of the compass are determined as follows:
• 0°
North
• 90°
East
• 180°
South
• 270°
West
Maintenance
With careful handling, the life of a binoculars is practically unlimited. The outside
surfaces of the optics should be carefully cleaned from time to time with a fine hair
brush.
Do not wipe off large dirt particles (e.g. sand) on the lenses but remove them with a hair
brush in order to avoid scratching the coating layer. Fingerprints should be wiped off
with an optical cloth after breathing on them or with a soft cloth. Do not use chemical
solvents
Object size in m x 100
Distance in m =
No of intervals, which the object
accepts on the graticule
Object size in m =
Distance in m x No of intervals which the object
accepts on the graticule
100