How to Use an Engineer Lensatic Compass By David Chandler The engineer lensatic compass is a precision instrument useful in measuring directions to objects and for land navigation. These compasses are not artillery compasses but are used in a very similar fashion. As the name implies, the lensatic compass employs a lens in the rear sight that allows precise readings of the dial. This precision is ineffective if the compass is improperly held or misused when taking an azimuth. Centerhold Technique Open the compass by folding down the thumb loop and opening the front cover until it is flat with the base of the compass.
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Page 3: Introduction A. Army and Troop Command. This compass is known throughout the world for its precision, reliability, versatility, ruggedness and much more. It has helped to save lives in times of war and provided many with recreational and commercial usefulness in times of peace. Page 4 Luminous Bezel Indicator: Used to mark an azimuth during day or night. Dial: Displays direction in reference to Magnetic North. The Dial is divided into two scales; a.
Outer - black printing graduated in mils. Page 5 6. Case Cover: Closes to protect the compass and reduce carrying size. When opened wide fig. When perpendicular fig. Page 6: Determine Direction C. Open the lensatic compass as shown in figure 2. Be sure the Dial floats freely. With the lensatic compass opened wide fig. Example: you want to follow an azimuth of degrees. Turn the fully opened compass and rotate the Bezel to align the lights in the case cover with the Luminous Bezel Indicator.
Rotate the Bezel counterclockwise to the azimuth desired. Each distinct click of the Bezel represents 3 degrees. Example: you want to follow a course of degrees. Page 9: Declination Adjustment a. Head for the point on the travel path that is beside the alternative steering mark. At this position sight a back azimuth to the old steering mark. A back azimuth is degrees away from a traveled azimuth. If traveled azimuth is less than degrees, add degrees. Page 10 2nd Method - With no declination diagram shown on the map.
Find the magnetic declination value in the map margin. Orient the map to the terrain. Sight an azimuth to any visible terrain feature that appears on the map. Place the fully opened lensatic compass on the map with the scale edge running through the terrain feature and with the compass reading the same as the azimuth sighted.
Page Definitions I. Azimuth - A horizontal angle in respect to North degrees, mils. The number directly under the black Index Line reads an azimuth on the Dial in either degrees or mils. Example: azimuth of 90 degrees or mils read 16 is due East. Page General Information 3. The declination will be shown in the marginal information on your map.
Positions are determined on a map by intersecting coordinates. The lower left is the origin and coordinates are read to the right and then up. Induction damping allows the Dial to seek Magnetic North and come to a complete rest in much less time than a unit without induction damping. It is a velocity dependent force; that is, as the speed of the oscillation of the Dial comes to rest, the damping force is zero.
Introduction B. Parts of the Lensatic Compass Figure 1 1. Luminous Bezel Indicator 2. Dial 3. Scale Edge 4. Sight Wire 5. Bezel 6. Case Cover 7. Case 8. Thumb Loop 9. Lanyard Lens Bracket
How to Read an Engineer Compass
How to Calibrate a Magnetic Compass By Anthony Thompson An engineer lensatic compass, also known as a hand compass or sighting compass, allows you to take bearings on physical landmarks which can then be used to determine your exact position on a map or navigate toward the landmark even when it can no longer be seen. This type of compass is also commonly used in the military and for orienteering. Step 1 Lift the front sight of the compass, which also acts as a protective cover, so it is at a degree angle to the base. Position the rear sight so it leans forward over the compass wheel at an angle of around 45 degrees.
How to Use an Engineer Lensatic Compass
When hiking, use a map to help you navigate unfamiliar terrain. Tritium is considered safe for external use because it is a weak beta particle emitter — so weak in fact that the radiation it emits cannot penetrate human skin. Then, from where you are, shoot an azimuth to the feature as accurately as possible, and calculate the back azimuth from that reading. A typical lensatic compass is shown at the right from FM Here, they agree, so there is no deviation and the measurements have been accurately taken. According to United States Army Corps of Engineers, the engineer compass is also called a lensatic compass. A plumb bob can lesatic suspended so that it cuts Polaris, and the bearing to the plumb bob cord then measured. To the north of State Route about 2 miles east of Windsor, Colorado there is Antelope Hill, a two-peaked hill about 50 ft.