Recta - More Than 100 Years of Heritage
HOW TO USE / SPECIAL FEATURES

Special features

1. Setting the declination factor

Recta compasses with declination correction are fitted with an adjusting screw, which allows you to adjust the easterly or westerly deviation. This screw is to be found on the reverse of the capsule. By turning this adjusting screw, the north marks are moved by the value of the declination in relation to the scale and the N-S grid lines on the compass capsule. Thus corrected, the north marks show the magnetic north while the scale and the N-S grid lines continue to display true north.



1 True north pole
2 Magnetic north pole
3 Deviation between the true and magnetic north poles = declination
4 Adjusting screw for declination correction
5 Screwdriver (supplied with the compass)

Procedure:

  • In the case of a westerly declination
  • = turn the adjusting screw counterclockwise
  • In the case of an easterly declination
  • = turn the adjusting screw clockwise
    Once a value is set, it is fixed mechanically and cannot be changed unintentionally.



    1 Westerly declination
    2 Easterly declination

    Note: The declination correction is especially important for globetrotters.


    To check the local need to adjust declination online, please visit National Geophysical Data Center (NGDC) website.

2. The clinometer

The clinometer enables you to measure ascents or descents. Frequently it would be useful to know the gradient of a slope, road or mountainside. This decisionmaking aid can be of great importance for your safety (avalanche risk, capability of vehicles for handling slopes, etc.) and reduces the risk. With the aid of the conversion table (from degrees to per cent) on the reverse of the mirror, you can easily measure heights (trees, houses, mountains, etc.).



A. Lateral measurement
This application can be used to determine gradients of
slopes, which pass directly across the user’s field of view.
It should be noted that the result always represents an
average figure.

  • Turn the reverse of the compass to face you, push in
    the mirror and block it with your finger.
  • Place the compass directly across the field of view along the incline or sight the incline over the compass
    edge.
  • The angle of inclination can be read off directly at the
    red mark on the red scale.



The angle of inclination can be read off directly
on the scale.


B. Longitudinal measurement
This application is intended for determining ascents and descents which are in a vertical direction relative to the observer. It is also possible to determine differences in height if the distance to the object is known.

  • Open out mirror and fix in position by light downward
    pressure.
  • Tilt the compass to one side and sight the desired point
    along the upper long edge.
  • Read off angle of inclination in the mirror (red mark on red scale).

  • The values read off can be converted to percentages with the aid of the conversion table on the reverse of the mirror (ascents, descents, difference of height, etc.).



    1 Align the lower long edge of the compass
    to the target to be sighted.
    2 Read off the angle of inclination in degrees
    directly on the scale.