Personal dosimeters ID 11. Technical characteristics of dosimetric monitoring devices

Wind force meter There are several models and, fortunately, those that are simpler are reliable, give reliable results, and are inexpensive. They consist of a clear graduated conical plastic tube with a wind inlet near the bottom and an outlet at the top.

a device designed to measure the absorbed dose of gamma and mixed gamma neutron radiation in the range from 10 to 1500 rad. ID-11 is an aluminum-phosphate glass activated by silver, which, after exposure to ionizing radiation, acquires the ability to luminesce under the influence of ultraviolet light. The luminescence intensity of this glass serves as a measure to determine the absorbed dose of radiation. Readings from the ID-11 dosimeter, which consists of measuring the luminescence intensity, are carried out by the GO-32 measuring device. The measurement result is displayed on a digital display and represents the total dose value collected by the dose meter during periodic (fractional) irradiation. ID-11 retains the accumulated dose for a long period of time (at least 12 months) and allows for repeated measurements. The ID-11 dose meter is issued in a sealed case, unauthorized opening of which is prohibited.

Dosimetry monitoring devices.

For dosimetric monitoring of radiation, a general-arms dose meter ID-1, an individual dose meter ID-11, dose meters from the DP-22 kits and an individual chemical dose meter DP-70 MP are used (Table 19.4).

3.1 . Set of military dose meters ID-1(Figure 10.5) is designed to measure absorbed doses of gamma neutron radiation.

The ID-1 case contains: ZD-6 charger, ID-1 dose meters - 10 pcs., technical documentation.

Technical characteristics of the ID-1 device

1 Measuring range from 20 to 500 rad.

2 Self-discharge 1 division per day;

3 Weight: - set in case 2 kg; - dose meter 40 g;

Charger 540 g.

Operating principle of the ID-1 device

Table 19.4.

Technical characteristics of dosimetric monitoring devices.

When a charged dose meter is exposed to ionizing radiation, positive and negative charges are formed in the volume of the ionization chamber, which are attracted to the corresponding electrodes and reduce their initial charge and voltage on the chamber electrodes. Accordingly, the repulsive forces between the quartz filament and the electroscope holder are reduced. As a result of these phenomena, the image of the thread moves on a scale ranging from 0 to 500, since the angle of deviation of the quartz thread from the electroscope holder is proportional to the radiation dose. The dose meter readings are viewed through the eyepiece when directed at any diffuse light source.

Rice. 10.5 Military dose meter ID-1

Preparation for work ID-1

To prepare the kit for work you need:

1. Unscrew the plugs on the dose meters using a triangular wrench

2. Turn the charger handle counterclockwise until it stops

3. Charge each dose meter in the following order:

4. Insert the dose meter into the charging socket

5. Point the charger with a mirror at an external light source and, turning the mirror, achieve maximum illumination of the scale

6. Press the dose meter and, observing through the eyepiece, rotate the charger handle clockwise until the filament image is set to scale zero

7. Remove the dose meter and check the position of the thread against the light

8. Screw on the dose meter cap

Other dose meters are charged by gradually turning the knob clockwise. Thus, from one extreme position to the other, up to 10-15 not fully charged dose meters can be charged. After charging the dose meters, turn the handle all the way counterclockwise.

Charged dose meters may be issued to personnel.

The value of the total radiation dose recorded by ID-1 is counted in rads on a scale. To take readings, ID-1 is viewed through the eyepiece when the meter is directed towards the light of any source.

During operation, to prevent mechanical damage, it is necessary to protect the kit from shocks, shocks, falls and protect it from dirt and harmful climatic influences (rain, snow, direct sunlight, etc.).

The device kit includes ten ID-1 dose meters and a ZD-6 charger.
Dose meter ID-1 provides measurement of absorbed doses of mixed y-neutron radiation in the range from 20 to 500 rad at a dose rate of up to 100 rad/s. The measured doses are counted on a scale located inside the meter.

3.2.Set of individual dosimeters ID-11(Figures 10.7, I0.8), designed to measure absorbed doses of gamma neutron radiation. The kit is used for individual monitoring of personnel exposure for the purpose of primary diagnosis of the severity of radiation injuries.

The ID-11 kit includes: measuring device (MD) (Figure 10.7), ID-11 detector - 100 pcs. (Figure 10.8), calibration detector GR, overload detector PR, power cables - 2 pcs., set of spare parts, canisters - 10 pcs., technical documentation.

Technical characteristics of the ID-11 kit

1. Measuring range from 10 to 1500 rad.

2. The measuring device is operational in stationary and field conditions at temperatures from minus 30 to 50°C.

3. Warm-up time before measurement is 30 minutes.

4. The dose measurement time for one ID-11 does not exceed 30 s.

5. Measurement error ±15%.

6. The detector is capable of accumulating dose upon repeated

irradiation, maintain it for at least 12 months and allow for repeated measurement of the received dose.

7. The power supply of the IU is carried out from an alternating current network with
voltage 220V and frequency 50Hz, as well as batteries with
voltage 12V and 24V, power consumption no more than 100W

The detector does not exceed 23g; -measuring device - 18kg.

Preparing for work and taking measurements using ID-11

Remove the plug from the socket of the measuring device, turn it on and warm it up for 30 minutes.

Insert the plug into the socket and set zero readings on the display using the ZERO SET knob.

Open the calibration detector using the key on the front panel of the measuring device. Insert the calibration detector into the socket of the measuring device. Use the sensitivity knob to set the values ​​recorded in the technical documentation on the display.

Open the overload detector and insert it into the socket of the measuring device. Observe that the “overload” indicator lights up.

To measure the dose, you need to open the working detector, insert the detector into the socket of the measuring device and after 30 seconds take readings on the digital display.

The ID-11 dose meter together with the GO-32 measuring device (Fig. 19.8) provides measurement of the absorbed dose in the range from 10 to 1500 rad.

3.3. Dose Meter Kit DP-22V(Fig. 19.9 ) designed to measure the absorbed dose of y-radiation.

Rice. 19.9. Set of dose meters DP-22V:
1 - Charger; 2- dose meters; 3 - power compartment;

4 - potentiometer handle; 5- CHARGE socket; 6 - cap.

The DP-22V set consists of 50 DKP-50A dose meters (Fig. 19.10) and a ZD-5 charger.

Rice. 19.10 Dose meter DKP –50A.
1 – ocular; 2 – scale; 3 – body; 4 – movable platinized thread;

5 – internal electrode; 6 – capacitor; 7 – protective frame; 8 – glass;

9 – ionization chamber; 10 – lens; 11– holder; 12 – top plug.

3.4. Individual chemical dose meter DP –70MP(Fig. 19.11) is designed to record the absorbed dose of gamma neuronal radiation and is issued to all personnel.

Rice. 11.19. Individual chemical dose meter DP –70MP:
1 - General form; 2- case; Z - cover of the case with a color standard;
4 - glass ampoule (dose meter).

Rice. 19.12. Field colorimeter PK-56M:
1 - frame; 2 - reading window; 3 - prism with eyepiece;

4 - ampoule holder; 5-retaining sleeve.

In units, the dose meter is not opened; readings are taken from it in medical units (institutions) where a wounded or sick soldier is admitted. Together with the PK-56M field colorimeter (Fig. 19.12), it provides measurement of radiation dose in the range from 50 to 800 rad.
Radiation doses are measured using a colorimeter scale. Inside the colorimeter body there is a disk with eleven light filters, the color of which corresponds to the color intensity of the solution in the ampoule.
The DP-70MP individual chemical dose meter allows you to measure the dose received both during single and repeated irradiation over 10-15 days.

A set of individual dosimeters is designed to measure absorbed doses of gamma neutron radiation in the temperature range from - 50°C to + 50°C, at relative air humidity up to 98%. The ID-1 set consists of 10 direct-indicating dose meters ID-1 and a charger ZD-6.

The dosimeter provides measurement of absorbed doses of gamma neutron radiation in the range from 20 to 500 rad at a dose rate from 10 to 360,000 rad/h.

1 rad. – 1.05 roentgens.

The division value is 20 rad, the measured doses are counted on a scale located inside the dosimeter, similar to the DKP-50A.

The self-discharge of the dosimeter does not exceed

a) under normal conditions: in 24 hours – 1 division, in 150 hours – 2 divisions

b) - 50°C - 1 division in 6 hours

50 °C – 3 divisions in 24 hours.

Warranty service life - at least 15 years (set) or operating time at least 5000 hours.

Dosimeter weight – 40 g.

Charger weight – 500 g.

The weight of the set in the case is 1500 g.

technical resource – at least 10,000 hours. The weight of the charger is 540 g, the weight of the entire set is 2 kg. with case.

The ZD-6 charger is intended for individual dosimeters ID-1, DKP-50A, DK-0.2, etc., having an outer diameter of 14 mm and a charging potential from 180 to 250 V.

Operating principles of building 6.

When the handle of a special mechanical device is rotated, pressure is created on the piezoelements, due to the deformation of which a voltage is generated that is supplied to the charging socket. The voltage is changed by changing the pressure on the piezoelements; to limit the voltage, a spark gap is connected parallel to the piezoelements.

How to charge the dosimeter:

Turn the charger handle counterclockwise until it stops;

Insert the dosimeter into the charging contact socket of the charger;

Point the charger with a mirror at an external light source;

Achieve maximum illumination of the scale by turning the mirror;

Press the dosimeter and, observing through the eyepiece, rotate the charger handle clockwise until the filament image on the scale is set to “0”, then remove the dosimeter from the socket.

Check the position of the thread against the light; if the thread is in a vertical position, its image should be at “0”.

Subsequent dosimeters are charged by gradually turning the handle clockwise until it stops (without returning it to its original position). After charging 10-15 dosimeters discharged to 30%, the handle is turned counterclockwise until it stops.

Individual dose meter ID-11 and measuring device (iu)

The set of individual dose meters ID-11 is intended for individual monitoring of people's exposure for the purpose of primary diagnosis of radiation injuries.

The set includes 500 individual dose meters ID-11, located in five storage boxes; measuring device DUT in a storage box, two power cables (a cable with a plug at the end for power from an alternating current network and a cable with special terminals at the end for power from an alternating current network and a cable with stamped terminals at the end for power supply from direct current from batteries), technical documentation spare parts, calibrated “GR” and overload “PR” detectors.

The weight of the set is 36 kg.

The individual dose meter ID-11 is a silver-activated aluminophosphate glass, made in the form of a keychain, and provides measurement of the absorbed dose of gamma neutron radiation in the range from 10 to 1500 rad.

Operation of ID-11 is ensured in the temperature range from –50 to +50°C under conditions of relative humidity up to 98%. Radiation doses are summed up during periodic irradiation and stored in the dosimeter for 12 months.

Irradiated ID-11 provides readings from the measuring device with an error of ±15% 6 hours after irradiation when stored under normal conditions. When measuring 14 hours after irradiation, the additional measurement error does not exceed 15%. ID-11 provides multiple measurements of the same dose. The weight of ID-11 is 25 g. The design of ID-11 consists of a body and a holder with a glass plate (detector). The serial number of the kit and the serial number of the individual meter are indicated on the holder. There is a cord on the body for securing the ID-11. To open and close ID-11, a key is installed on the front panel of the control unit.

Individual radiophotoluminescent dose meter ID-11 is designed to measure the absorbed dose of gamma and mixed gamma-neutron radiation in the range from 10 to 1500 rad.

Dose meter ID-11(Fig. 10.15) is a silver-activated aluminophosphate glass, which, after exposure to ionizing radiation, acquires the ability to luminesce under the influence of ultraviolet light. The luminescence intensity of this glass serves as a measure to determine the absorbed dose of radiation.

Rice. 10.15. Dose meter ID-11:

1 - holder; 2 - silver-activated aluminophosphate glass plate - ionizing radiation detector; 3 - body; 4 - cord.

Readings from the ID-11 dosimeter, which consists of measuring the luminescence intensity, are carried out by the GO-32 measuring device (Fig. 10.16). The measurement result is displayed on a digital display and represents the total dose value collected by the dose meter during periodic (fractional) irradiation. The ID-11 dose meter stores the accumulated dose for a long period (at least 12 months) and allows for repeated measurements. The ID-11 dose meter is issued to military personnel in a sealed case, unauthorized opening of which is prohibited. The dose meter is carried in a tunic pocket or in a secret trouser pocket. Dose meter weight - 23 g.

Fig. 10.16. Measuring device GO-32:

1 - ZERO SETTING knob; 2 - POWER toggle switch; 3 - indicator board; 4 - overload indication; 5 - calibration number; 6 - CALIBRATION knob; 7 - plug; 8 - socket for installing the detector; 9 - KEY for opening the detector; 10 - carrying handle.

The issuance of dose meters to personnel together with a dose record card is carried out by order of the commander of the military unit. The issuance of the list is carried out by the foreman of the unit. Issued military and individual dose meters must be in working order. The initial readings of ID-11 at the time of issue must be recorded.

Preparation and work with the GO-32 device. Turn on the device with the POWER toggle switch and warm it up for 30 minutes. Use the ZERO SETTING knob to set “O”; remove the plug. Use the CALIBRATION knob to set the calibration number. Using the KEY, open the detector, insert it into the measuring channel and push it all the way. Take the third or fourth reading. Press to return the detector to its original position and remove it. It is prohibited to recess the moving glass without a detector.

Readings from military dose meters in units are taken by immediate superiors or persons appointed by them. During a long stay in a contaminated area, the frequency of taking readings from military dose meters is established by the senior commander. Readings from individual dose meters are taken at the medical center of the military unit.

Based on military radiation monitoring data, each company and individual platoon keeps a log of radiation doses received by unit personnel. The total value of radiation doses is periodically recorded in individual dose cards. When a serviceman is transferred (business trip) to another unit (unit), the total dose received by the serviceman is recorded in the prescription (dose record card) and registered at the place of the new assignment (business trip). When the wounded and sick are moved from one medical point (hospital) to another, the total radiation dose received by the military personnel is recorded in the medical history, and upon discharge from the medical institution - in the dose record card.

Chapter 11. MILITARY TOPOGRAPHY

Military topography gives knowledge about the terrain, teaches how to navigate it, the skillful use of topographic maps and aerial photographs when performing various combat missions, techniques for working with a map on the ground, and drawing up graphic documents.

The study of military topography contributes to the development of such important qualities as observation and accuracy, the ability to analyze observation results and draw conclusions about the influence of the terrain on the performance of a combat mission.

The main issues in topographical training of internal troops sergeants are terrain orientation and movement along azimuths, which are carried out only practically and on unfamiliar terrain.

WAYS TO STUDY THE AREAS

The terrain is being studied in relation to the upcoming service and combat mission. The following main methods are used to study the area.

Area reconnaissance.

Terrain reconnaissance (direct inspection and examination) is the main and most advanced method, since it allows you to most completely and reliably study and evaluate all the features of the terrain (the nature of the relief, traffic conditions, the presence and condition of roads, hidden approaches, command heights, natural obstacles etc.), their influence on the actions of their unit, neighbors and enemy.

One of the ways to reconnaissance of an area in advance is reconnaissance, i.e. survey and study of the area by walking around it or bypassing it. This method is widely used in combat situations for reconnaissance of individual areas and lines, movement routes, river crossing areas, etc.

However, the situation does not always allow you to personally inspect the desired site, route or area, therefore, along with inspecting the area, other methods of studying it are used.

Studying the area using a map. Large-scale topographic maps make it possible to study the terrain in advance and quickly in any conditions, regardless of the size of the area, its remoteness and the presence of the enemy on it. A preliminary study of the terrain during reconnaissance operations, organizing a march, preparing and organizing a battle is always carried out on a map.

A military topographic map is a faithful assistant to an officer and sergeant. It gives a clear picture of the area. From the map you can easily determine where and what roads are located, their condition, surface, steepness of descents and ascents, length and width. Having found a bridge on the map, you can not only tell what material it is built from (wood, iron, etc.) , but also determine its width, length and load capacity. The map makes it possible to find out the width of the river, its name, direction and speed of flow, ford depth and bottom quality; forest type and age; the number of courtyards in a settlement and its name, the presence of telegraph and telephone communications in a given settlement, etc. In addition, using the map you can get a complete picture of the topography of a given area.

Using a topographic map, you can solve a number of important problems: determine distances, outline hidden approaches and paths for movement; determine your location, the position of targets and quickly indicate them to persons located at other observation points; prepare initial data for opening artillery and machine gun fire; move without roads in closed areas at night, in fog, having previously determined the azimuths for movement from the map. Having studied the area on the map, you can outline the likely places of concentration of enemy troops, possible routes of movement, places of unloading of his troops, etc.

When using the map, however, it is necessary to take into account that it is impossible to put on it all the details of the terrain that are important for unit commanders. In addition, the map does not reflect all the changes in the area that have occurred since the moment it was taken, and therefore is often more or less out of date. The terrain changes especially dramatically in combat conditions. Using the map, it is also impossible to determine terrain conditions that depend on the time of year, for example, the passability of roads and swamps in winter or during muddy times, etc.

All this additional data about the area should be obtained by reconnaissance. In this case, especially when studying terrain occupied by the enemy, aerial photographs can provide significant assistance.

Studying the area using aerial photographs. Aerial photographs are obtained by photographing an area from an airplane. Compared to a map, they provide more recent and detailed information about the area. Using them, you can study not only the terrain, but also the location, nature of the enemy’s defensive structures, fire weapons, and the places where his manpower and military equipment are concentrated. However, the images also do not provide complete information about the area, for example, the passability of swamps, the depth of fords, the speed of the river, etc.

Study of the area through interviews with local residents and interrogations of prisoners. This method is used in the absence of sufficient data obtained by other methods, as well as to verify and clarify individual details. Information obtained in this way must be carefully checked against other sources.

Thus, all of the listed methods of studying the area complement one another. Only their skillful combination and application depending on the situation can provide the commander with the most complete data about the area of ​​upcoming operations.

Typical landforms and main types of terrain

The terrain forms are very diverse. The following landforms exist (Fig. 11.1).

Mountain (height) - a dome-shaped or conical hill, from the top of which slopes (slopes) radiate in all directions. Its base is called the sole. A small mountain is called a hill, and an artificial hill is called a mound. The heights from which a good view opens up are called commanding heights.

Rice. 11.1. Typical relief forms and their schematic representation.

Basin - closed cup-shaped depression. A small depression is called a pit.

Ridge - a hill stretched in one direction. The line along the ridge along its crest, from which the slopes diverge in opposite directions, is called a watershed or topographic ridge.

Hollow - an elongated depression sloping in one direction. The line connecting the slopes along the bottom of the hollow is called a weir. A large, wide hollow with gentle slopes and a low-sloping bottom is called a valley, and a narrow one with very steep slopes is called a gorge if it cuts through a mountain range, and a ravine if it is located on a plain or on a mountainside.

Saddle - the lower part of the crest of a ridge or elongated mountain, located between two adjacent peaks. A saddle is the junction of two valleys that diverge in opposite directions. In the mountains, saddles through which mountain roads and trails pass are called passes.

Each of the listed landforms has its own tactical significance.

Hills (heights, ridges) are advantageous for placing trenches and observation posts on them, because visibility and shelling of the surrounding area is improved. In this case, however, one should take into account the shapes of the slopes, which have different effects on viewing and firing conditions.

There are the following main shapes of slopes: smooth, concave, convex and wavy. The flat and concave slopes are clearly visible along the entire length from the topographic ridge to the bottom and have no areas that cannot be shot. A convex slope, on the contrary, convexly blocks part of the terrain from view, forming a field of invisibility and a non-shootable space.

The wavy slope is a combination of convex and concave slopes. The convex bend (ridge), from which the best view and shelling of the slope opens up to its base and which is not projected against the sky when observed from the enemy, is called, in contrast to the topographical, a combat or artillery ridge. It is always located on a slope below the topographic ridge and is therefore convenient for the location of trenches, observation posts, and anti-tank guns. On flat and concave slopes, the combat ridge runs close to the topographic one and almost coincides with it.

The slopes of the hills facing the enemy are called front slopes, and those facing in the opposite direction are called reverse slopes. Reverse slopes are convenient for the location of artillery and mortar firing positions, equipment of dugouts, combat feeding points, etc.

Hollows, ravines, saddles and reverse slopes of hills serve as good hidden approaches, and craters, pits and mounds serve as shelters during dashes.

When determining the possibility of movement on the ground, it is also necessary to take into account the steepness and length of the slopes.

The nature of the terrain can be very diverse. For combat conditions, the following varieties are usually distinguished:

The nature of the relief is flat, hilly and mountainous;

The nature of the soil and vegetation cover includes wooded, swampy, steppe and desert areas.

In all cases, the terrain influences the combat operations of troops in one way or another. When assessing the tactical properties of any type of terrain, it is first determined to what extent the terrain is covered by the terrain and local objects that limit visibility and observation (closed, semi-open, open), as well as to what extent it is crossed and indented by obstacles (ravines, rivers, lakes, large ditches, stone fences, etc.) affecting the movement of troops (crossed, slightly crossed, uncrossed).

Open terrain makes it easier to control troops and observe the battlefield, but makes it difficult to camouflage, shelter from fire, and communicate with the rear.

Rough terrain makes it difficult to move troops and military equipment.

READING TOPOGRAPHIC MAPS

The concept of topographic maps, plans and diagrams. A topographic map is a detailed and accurate image of the terrain on a plane (paper), made with conventional symbols with all terrain lines reduced by 10, 25.50 thousand times or more (up to a million).

Maps depicting the entire earth's surface or a significant part of it (an entire continent, country) with a reduction of more than a million times are called geographical maps.

The ratio showing how many times all terrain lines are reduced when depicting them on a map is called the map scale. The smaller this decrease, the larger the image of the area, and therefore the scale of the map, and vice versa. Obviously, the larger the scale of the map, the more detailed and accurate the terrain can be depicted on it.

An accurate and detailed image of individual small sections of terrain (up to 100 km in length and width), made by conventional signs with a decrease in the linear dimensions of the area by 10 thousand times or less, is called, in contrast to a map, a topographic plan.

Using large-scale topographic maps and plans, you can study the terrain in sufficient detail and accurately and navigate it, make the necessary measurements and calculations, and prepare data for firing and target designation.

Topographic maps are printed in separate sheets, the sizes of which are set for each scale. The side frames of the sheets are meridians, and the top and bottom frames are parallels. On all maps, the top frame always faces north. All this allows, if necessary, to easily glue together several folded sheets of map.

Given the importance of topographic maps and plans as detailed and accurate documents about the area, they must be carefully protected so that they do not fall into enemy hands.

A simplified drawing that shows only some of the basic elements of the terrain that are important for performing a specific task is called a diagram. Schemes are usually drawn up by eye or according to an existing map and are used in the preparation of combat graphic documents for various purposes: target diagram, route diagram, report diagram, etc.

Measuring distances on a map. To measure distance on a map, you need to know its scale.

The scale is always indicated below the bottom (southern) frame of the map and is expressed numerically or graphically (Fig. 11.2). In the first case it is called a numerical scale, and in the second - a linear scale.

Signature 1:25,000 - numerical scale (reads “one twenty-five thousandth”). It means that all terrain lines are depicted on this map with a reduction of 25 thousand times, i.e. 1 cm corresponds to 25000 cm on the map and Rice. 11.2. Linear and numerical scales.

250 m - on the ground. This distance, corresponding to 1 cm on the map, is called the scale value and is always inscribed on the map between the numerical and linear scales.

When using a numerical scale, the distance on the map is measured in centimeters using a ruler with centimeter divisions. Then, knowing the scale, multiply by the number of centimeters measured on the map. For example, on a map with a scale of 1:25000, the distance measured is 5.3 cm. This distance on the ground will be 250m x 5.3 = 1325m.

Even simpler, without any calculations, distances on the map are measured using a linear scale, using a compass or a strip of paper. They do it like this (Fig. 11.3):

The legs of the compass are installed at points on the map, the distance between which needs to be determined;

Then, without changing the angle of the compass, apply it to the linear scale so that one of the legs exactly coincides with the zero or with the signed division Rice. 11.3. Measuring distance on a map

to the right of zero, and the other is located using linear scale on small divisions to the left of zero;

The required distance is obtained as the sum of the readings read on the scale against both legs of the compass.

TERRAIN ORIENTATION

To navigate the terrain means to determine one’s location and the desired direction of movement (action) relative to the sides of the horizon, surrounding local objects, relief elements, as well as the location of one’s troops and enemy troops, and to understand the position of lines, landmarks, engineering structures and other objects on the ground.

You can navigate the area with or without a topographic map. When orienting without a map, it is necessary to determine the sides of the horizon. With varying degrees of accuracy and reliability, the sides of the horizon can be determined on the ground using a compass, by celestial bodies, and by some signs of local objects.

By compass. Determining the sides of the horizon using a compass is performed in the following sequence: release the magnetic needle from the brake; by rotating the compass cover, align the reference pointer at the front sight of the sighting device with the zero division of the dial; position the compass horizontally and rotate its body so that the zero division of the dial aligns with the northern end of the magnetic needle; using a sighting device, select a local object that is located in the north direction; other sides of the horizon are found by the corresponding marks on the compass dial.

To more accurately determine the direction to the north, it is advisable to install the compass on a stationary horizontal base.

The presence of large metal objects, radio transmitting and radio receiving devices near the compass introduces large errors into its readings. Therefore, when determining the direction of movement using a compass while marching in armored and automotive vehicles, you should move away from the vehicle at a distance of at least 30 m, while keeping the machine gun in the “behind your back” position. When orienting using a compass directly in the car cabin, it is necessary to determine in advance the correction to the compass readings.

According to the position of the Sun. The Sun moves across the sky from east to west at an angular speed of 15° per hour, and at noon local time it is in the south. According to the Sun and the clock The sides of the horizon are determined in the following sequence: the watch is held horizontally, so that the hour hand is directed towards the Sun (Fig. 11.4); The angle between the hour hand and the direction from the center of the dial to the number “I” in winter and the number “2” in summer is divided in half. The line dividing this angle in half will indicate the direction to the south.

At night, identifying sides Rice. 11.4. Determining directions for the horizon is easiest to navigate on the polar side of the horizon using a clock.

star(Fig. 11.5). This star is always there

in the north. Therefore, if you stand facing it, north will be in front, south behind, east on the right, and west on the left. To do this, you need to find the constellation Ursa Major. Then mentally continue the straight line segment between the two extreme stars of the “bucket” of the constellation towards its expanded part and set it aside five times. The resulting point will indicate the position of the North Star, which is part of the constellation Ursa Minor and is always located in the north direction.

Rice. 11.5. Determining directions to the sides of the horizon using the North Star.

During a full moon, the sides of the horizon can be determined by the Moon using a watch in the same way as by the Sun.

If the Moon is incomplete (waxing or waning), then you need to:

Divide by eye the radius of the Moon's disk into six equal parts, determine how many such parts are contained in the diameter of the visible crescent of the Moon, and note the time on the clock;

From this time, subtract (if the Moon is waxing) or add (if the Moon is waning) as many parts as are contained in the diameter of the visible crescent of the Moon. In order not to make a mistake when to take the difference and when to take the sum, you can use the method shown in Fig. 11.6; the resulting sum or difference will show at the hour when the Sun will be in the direction where the Moon is located;

Combine the direction to the Moon with the place on the dial that corresponds to the one obtained after adding or subtracting the time. The bisector of the angle between the direction to the Moon and one hour (winter time) or two hours (summer time) will show the direction south.

Rice. 11.6. Rule for

establishing a definition

Mark positions on