Archive for the ‘Lensatic Compass’ Category
Compass to Cheek Method!
Sighting the Compass!
The Compass to Cheek method of holding a Lensatic Compass is used almost exclusively for sighting. Obviously, if using, there must be enough light to see the far distant aiming point/object. The following sequential steps can be used to place the compass into operation:
- Open the Lensatic Compass cover (w/sighting wire) to a vertical position.
- Pull up the sighting lens slightly, place thumb through the thumb loop and provide a steady base by forming a fist around the thumb with four remaining fingers.
- Take second hand and grasp supporting hand and depict in diagram above.
- Lift compass to cheek and look through the rear-sight slot and align the front-sight hairline with the far distant aiming point/object.
- Glance down at the dial through the eye lens and read the direction/azimuth in either degrees or mils.
Remember, the direction/azimuth obtained with a Lensatic Compass is a magnetic reading and must be converted to a grid direction/azimuth before plotting on a map.
Using a Lensatic Compass!
Centerhold Position!
There are several Lensatic Compass holding techniques; however, in the interest of expedience, this posting will cover the most common and generally preferred method. The Centerhold Technique is assumed by:
- Open the compass (fullest extent).
- Move rear sight to the upright position (unlocks floating dial).
- Place thumb through the thumb loop; form a steady base with third and fourth fingers; extend index finger along side the compass; place other thumb between the rear sight and the compass dial; extend the index finger along the other side of the compass and remaining fingers around the other hand; pull your elbows into your side and turn your body in the direction of the target/object for azimuth reading/determination.
To determine the azimuth, once the compass is pointing at the target, look down and read the azimuth from beneath the fixed black index line. Remember, this is a magnetic reading and must be converted to Grid before plotting on a map.
Compass Handling!
Magnetic, Lensatic Compass!
A Lensatic Compass does not require a large amount of maintenance. However, prior to use, it should be inspected for operability, insuring: 1. The sight wire is serviceable and in place; 2. Neither the sight glass or crystal face is broken; 3. The floating dial is not stuck and functions freely/properly.
The compass should be checked periodically to insure it delivers a correct reading. This is done by comparing the applicable compass direction/azimuth reading with the known surveyed data (direction/azimuth) to the same aiming point. If the compass is off more than 3 degrees, it shouldn’t be used. When not in use, the eye lens of the Lensatic Compass should be in the down position, locking/securing the floating dial and also providing protection to the crystal face/rear sight.
Metal objects and electrical sources will adversely affect a magnetic compass reading. Therefore, to preclude this from happening, the following minimum separation distances must be followed:
- Power Lines – 55 meters;
- Vehicles – 18 meters;
- Telephone or Barbed Wire – 10 meters;
- Small Metal Objects (rifle/pistol) – ½ meter.
The Compass!
Convenient/Accurate/Reliable
As with the Topographical Map, a compass is an essential component to Land Navigation. There are many makes, models, and styles; however, for the sake of my knowledge and verifiable dependability, I would suggest a Lensatic Compass.
This compass should be characterized by illumines markings so it can be used during the hours of limited visibility. To further facilitate easy use, it should have a magnifying lens and a dial that is graduated in both mils and degrees. There are both reputable US Military and lesser dependable but still useable civilian Lensatic Compasses.
The compass pictured above is used, on a daily basis, by our Military Forces. If procured from a reputable retail outlet and if advertised as an authentic“US Military Lensatic Compass”, you can be assured that it would give you years of good/dependable service.