PS31 Manual

INTRODUCTION

1.1. GENERAL INFORMATION

1.1.1. SCOPE

This manual provides operation and maintenance instructions for the Night Vision Goggles (NVG) ATN PS31, hereinafter referred to as the NVG. The NVG is a self-contained night vision device that enables improved night vision using ambient light from the night sky (moon, stars, skyglow, etc.).

Model Number and Basic Description
ATN PS31 - Night Vision Goggles

Supplier
American Technologies Network Corp.
2400 NW 95 Ave, Doral, FL 33172

1.1.2. WARRANTY INFORMATION

This item shall conform to design, manufacturing, and performance requirements and be free from defects in material and workmanship for a period of two (2) years from the date of acceptance. If an item is defective, notify ATN or the point of purchase contact.

1.1.3. TECHNICAL INFORMATION

For technical information contact ATN Corp. directly at 650-989-5100, or info@atncorp.com, or your point of purchase contact.

TABLE 1.1. NOMENCLATURE CROSS-REFERENCE LIST
Common Name	Official Nomenclature
Battery	Battery Non-rechargeable
Battery Cap	Cover Battery Retainer
Carrying Case	Case, Infrared Equipment
Carrying Case Strap	Strapping
Eyepiece Lens Cap	Cap, Protective, Dust
Head Mount	Headset Assembly
Helmet Mount	Mount, Viewer
Goggles	Goggles Assy
Objective Lens Cap	Cap, Protective, Dust

1.1.4. LIST OF ABBREVIATIONS AND ACRONYMS

• BII - Basic Issue Items
• CAGEC - Commercial and Government Entity Code
• cm - Centimeters
• FM - Field Manual
• Hrs - Hours
• IR - Infrared
• JTA - Joint Table of Allowances
• lbs - Pounds
• LED - Light Emitting Diode
• NVG - Night Vision Goggles
• N/A - Not Applicable
• NBC - Nuclear, Biological, and Chemical
• NSN - National Stock Number
• Pam - Pamphlet
• PASGT - Personal Armor System Ground Troops
• PMCS - Preventive Maintenance Checks and Services
• Qty - Quantity
• Recm - Recommended
• Rqr - Required
• SF - Standard Form
• TDA - Table of Distribution and Allowances
• TM - Technical Manual
• TOE - Table of Organization and Equipment
• Vdc - Volts, direct current

1.1.5. GLOSSARY

BLACK SPOTS. These are cosmetic blemishes in the image intensifier of the NVG or dirt or debris between the lenses.

BRIGHT SPOTS. These defects can appear in the image area of the NVG. This condition is caused by a flaw in the film on the micro channel plate. A bright spot is a small, nonuniform, bright area that may flicker or appear constant. Bright spots usually go away when the light is blocked out and are cosmetic blemishes that are signal induced.

CAUTION. Conditions, practices, or procedures that must be observed to avoid damage to equipment, destruction of equipment, or a long-term health hazard.

CHICKEN WIRE. An irregular pattern of dark thin lines in the field-of-view either throughout the image area or in parts of the image area. Under the worst case condition, these lines will form hexagonal or square-wave shaped lines.

DARK (OR DARK AREA). A place in which there is very little light. It does not mean total darkness. Generally, this means conditions similar to a quarter-moon or starlit night.

DARK-ADAPTED. Having one's eye adjusted to the goggles output under low light conditions.

DIOPTER. A unit of measure used to define eye correction. Adjustments to the diopter adjustment will provide a clearer image in each eye.

EDGE GLOW. This is a defect in the image area of the goggles. Edge glow is a bright area, sometimes sparkling, in the outer portion of the viewing area.

EMISSION POINT. A steady or fluctuating pinpoint of bright light in the image area and does not go away when all light is blocked from the objective lens of the goggles. The position of an emission point within the image area of the goggles does not move. An emission point should not be confused with a point light source in the distance.

FIXED-PATTERN NOISE. This is a cosmetic blemish in the image area characterized by a faint hexagonal honeycomb pattern throughout the viewing area that most often occurs at high light levels or when viewing very bright lights.

FLASHING. This is a defect in the image area of the goggles. The image appears to flicker or flash.

FLICKERING. See "flashing."

GAIN. This is the number of times a night vision device amplifies light input.

IMAGE INTENSIFIER. An electro-optical device that detects and amplifies ambient light to produce a visual image.

INFINITY FOCUS. Adjustment of the objective lens so that a distant object, such as a star or the point light on a distant tower, forms the sharpest image.

INTERMITTENT OPERATION. This is a defect in the image area of the goggles. See "flashing".

IR SOURCE. This is an IR Light Emitting Diode (LED). When turned on, the IR source provides additional illumination to enhance existing light conditions used only for performing nearby tasks.

MICROCHANNEL PLATE. A current-multiplying optical disk that intensifies the electron image produced by the photocathode.

NOTE. Essential information of special importance, interest, or aid in job performance.

PHOTOCATHODE. The input optic of an image intensifier that absorbs light energy and in turn releases electrical energy in the form of an electron image.

SCINTILLATION. A faint, random, sparkling effect throughout the image area. Scintillation is a normal characteristic of the image intensifier and should not be confused with emission points. Scintillation is more pronounced under low light conditions. Also called "video noise".

SHADING. The viewed image should be a full circle. If shading is present, you will not see a fully circular image. Shading is indicative of a dying photocathode and is caused by a defective vacuum seal of the image intensifier. Shading is very dark and you cannot see an image through it.

WARNING. Conditions, practices, or procedures that must be observed to avoid personal injury or loss of life.

EQUIPMENT DESCRIPTION

1.2.1. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES

The NVG is a hand-held, head mounted, helmet mounted night vision system that enables walking, weapon firing, short-range surveillance, map reading, vehicle maintenance, and administering first aid in both moonlight and starlight. Each unit allows for vertical adjustment, fore-and-aft adjustment, objective lens focus and eyepiece focus. The goggles are also equipped with an IR source.

1.2.2. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS

The NVG includes the items shown in Figure 1.1. The major components are the head mount, helmet mount, goggles, and carrying case.

a. Goggles
The goggles consist of various components such as an objective lens, an image intensifier (not shown), an eyepiece lens and a battery cap.

b. Head Mount (Optional)
The head mount secures the goggles to the operator's head for night viewing and provides freehand support for use with a weapon, protective mask or other purposes. It is adjustable and cushioned.

c. Helmet Mount
This item secures the goggles to the Personal Armor System Ground Troops (PASGT) helmet allowing freehand support for use with a weapon, protective mask and/or other purposes.

d. Carrying Case
The carrying case is provided for transportation and protection of the goggles, head mount, battery and accessories. Two slide keepers are provided for belt attachment and three D-rings for shoulder and leg strap attachment. A carrying case strap is also provided which can be attached to the two D-rings on the back of the carrying case.

1.2.3. EQUIPMENT DATA

The following tables provide information pertaining to the operational, electrical, mechanical, optical, and environmental characteristics for the goggles.

TABLE 1.2. OPERATOR ADJUSTMENT LIMITS
Diopter Adjustment	-6 to +2 diopters
Objective Focus	250 mm to infinity

TABLE 1.3. ELECTRICAL DATA
Battery Requirements	Model: CR123 battery (No. 1.5)
Continuous Working Hours	At normal temperature, the power supply of the built-in battery compartment is not less than 10 hours.

TABLE 1.4. MECHANICAL DATA
Carrying Case	Size: Approx. 14" x 8"
Goggles	Weight: 560 grams

NOTE:
Weight of the goggles does not include accessories.

TABLE 1.5. OPTICAL DATA
Magnification	1x +/- 0.05
Field-of-View	≥40 degrees
Diopter Focus	-6 to +2 diopters
Objective Focus	250 mm to infinity
Resolution	Target contrast is 85%, illuminance 1x10-1 lux, not more than 1.0 milliradian; when the target contrast is 35% and the illumination is 1x10-3 lux, it is not more than 2.4 milliradians.

TABLE 1.6. ENVIRONMENTAL DATA
Goggles Operating Temperature	-51°C to +49°C
Goggles Storage Temperature	-51°C to +85°C
Illumination Required	Overcast starlight to moonlight

PRINCIPLES OF OPERATION

1.3.1. MECHANICAL FUNCTIONS

The mechanical functions of the NVG allow for differences in the physical features of individual operators and provide for operating the system. These functions include the power switch, eye relief adjustment, diopter adjustment, and objective focus.

1.3.2. OPTICAL FUNCTIONS

The optical functions include an objective lens, image intensifier and eyepiece lens. The objective lens collects light reflected from the night scene by the moon, stars, or night sky, inverts the image and focuses that image on the image intensifier. The image intensifier converts the captured light into a visible image and re-inverts the image which can then be viewed through the eyepiece lens.

1.3.3. ELECTRONIC CIRCUIT FUNCTION

The electronic circuit regulates the direct current voltage from the battery to the image intensifier and IR source as required. It also monitors the output voltage of the battery and turns on a low-battery indicator when the available battery voltage is less than 1.5v.

• Power Source. The electronic circuit is powered by one battery.
• Auto Mode. The automatic mode is different from the "IR" mode, and the automatic mode starts the environment detection sensor. It can detect environmental luminance in real time and work with reference to the illumination control system. Under extremely low or extremely dark environment, the system will automatically turn on infrared auxiliary lighting, and when the environmental illumination can meet normal observation, the system automatically turns off IR. When the ambient illumination reaches 40-100 Lux, the whole system is automatically shut down to protect the photosensitive core components from damage by strong light.

DESCRIPTION AND USE OF OPERATOR'S CONTROLS AND INDICATORS

NOTE:
The NVG is a precision electro-optical instrument. Handle it carefully. If the equipment fails to operate, refer to the Troubleshooting Procedures in Chapter 3.

2.1.1. OPERATOR CONTROLS AND INDICATORS

The NVG is designed to adjust for different users and corrects for most differences in eyesight. The controls and indicators for the NVG are shown in Figure 2.1., which are described in Table 2.1.

NOTE:
Low battery indicator and IR source ON indicator are visible in the eyepiece lens.

Controls and Indicators	Functions
Power / Manual Gain Knob	Press the knob once - turn the goggles on. Press the knob once again - turn the goggles off. Press the knob twice - turn on the IR light after the unit is on. Press the knob five times - turn on the auto shut off function, allowing goggles to turn off automatically when flipped up on a helmet mount.
Objective Lens	Focuses objective lens. Adjusts for sharpest image of viewed object.
Diopter Adjustment	Focuses eyepiece lens for use without the need for glasses. Adjust for the sharpest image of the intensifier screen.
Eye Relief Adjustment	Adjusts the distance between your eye and the goggles.
Latch	Latch used for separation of goggles from head-mount/helmet mount.
Battery Polarity Indicators	This feature, molded into the battery housing, shows the proper orientation of the battery. Some versions have a bubble molded into the top of the battery house to show the plus polarity for proper orientation.

PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS)

2.2.1. PREVENTIVE MAINTENANCE CHECKS AND SERVICES TABLE

a. General
To ensure the readiness of the NVG, perform the preventive maintenance procedures in accordance with Table 2.2 prior to each mission. Preventive maintenance procedures include inspection, cleaning, and performance of the checkout procedures.

b. Warnings and Cautions
Always observe the warnings and cautions appearing in the table. Warnings and cautions appear before applicable procedures. You must observe the warnings and cautions to prevent serious injury to yourself and others, or to prevent your equipment from being damaged.

c. Explanation of Table Entries

• Item Number Column. Numbers in this column are for reference.
• Interval Column. BEFORE procedures must be done before you operate or use the equipment. DURING procedures must be done while operating the equipment. AFTER procedures must be done immediately after use.
• Location / Check / Service Column. This column provides the location and the item to be checked or serviced.
• Procedure Column. This column gives the procedure required to check or service the item.
• Not Fully Mission Capable If Column. This column identifies faults that prevent the equipment from performing its primary mission.

d. Other Table Entries
Be sure to observe all special information and notes that appear in the table.

Item No.	Interval	Location / Check / Service	Procedure	Not Fully Mission Capable If
1	Before	Open carrying case	Check the inventory items.
2	Before / After	Goggles optical surfaces	Inspect all lenses, including objective, eyepiece, IR lens and high light cut-off window, for dirt, fingerprint residue, chips, or cracks. If necessary, clean and dry lenses with water and lens tissue.	Scratches or heavy scratches that hinder vision with goggles turned on, or if cracks are present.
3	Before / After	Battery cap housing	Inspect external surfaces for cracks or damage. Remove battery cap and inspect for moisture, cracks, corroded or defective spring contacts, and O-ring present in cap.	Cracks or damage in the battery housing. Cap is missing, contacts damaged or corroded, or O-ring is missing.
3 cont.	Before / After	Battery cap housing cont.	Remove the battery and press the knob inward to turn the unit on or off. Install battery and check IR source functions. Check the high light cut-off with daylight or bright room light by placing the lens cap on the objective lens. Turn goggles on and observe that the system cuts off within 70 ±30 seconds.	Knob is broken or missing.
4	Before / After	Goggles	Inspect for cracks or damage. Scratches, cracks, chips and gouges are acceptable if operation is not affected.	Cracks or damage in the goggles.
5	Before / After	Eyepiece lens	Rotate diopter adjustment to make sure the eyepiece lens moves freely and is not loose.	Binding, not moving freely or too loose.
6	Before / After	Eyecup	Inspect for dirt, dust, cracked or torn eyecup. Inspect for bent, broken, or improperly fitting eyepiece lens. If necessary, clean with water.	Chips and cracks are permitted on the eyecup retaining rings as long as they do not interfere with installation of eyecup.
7	Before / After	Objective lens	Rotate focus ring to ensure free movement. Check objective lens for chips, cracks and dents.	Focus ring is binding or not able to move.
8	Before / After	Viewed image	Operator may use the TS-4348/UV to check resolution. Refer to paragraph 2.2.3 to inspect for operational defects.	Flickering, flashing, edge glow, or shading is observed.
9	Before / After	Socket	Inspect for dirt, dust, or corrosion. Insert goggles latch into socket to verify secure attachment of goggles to headmount. If necessary, clean socket with water.	Damaged, latch won't lock or is too loose.
10	Before / After	Eye relief adjustment	Press the eye relief adjustment and check for free motion. Inspect for damage.	Binding, damaged or non-operational slide mechanism.
11	Before / After	Helmet mount straps	Inspect for cuts, tears, fraying, holes, cracks, or defective fasteners.	Damage causes straps to be unserviceable.
12	Before / After	Fore-and-aft adjustment	Press the two side buttons on plastic mount or depress side lever on metal mount and check for free motion. Inspect for damage.	Binding, damaged or non-operational slide mechanism.
13	Before / After	Mounting adapters, headmount / helmet mount	Inspect for dirt, dust or corrosion. Insert into headmount or helmet mount socket to verify secure attachment.	Damaged, will not latch securely.
14	Before / After	Carrying case	Remove all items and shake out loose dirt or foreign material. Inspect for tears, cuts, excess wear, or damage to mounting clips.

NOTE:
If the goggles fail the highlight cut-off test, it does not cause the end item to be nonmission capable. However, it should be sent to higher level of maintenance as soon as possible.

2.2.2. Resolution Check Using the TS-4348/UV Test Set

NOTE:
The TS-4348/UV Test Set can be used by the operator to check the resolution of the goggles at any time. NOTE:
The TS-4348/UV Test Set can be used by Direct Support/Intermediate Level to perform the resolution testing 180 Day Service. If a system fails it must be tested on the TS-3895A/UV Test Set. NOTE:
Verify the resolution of the goggles using the TS-4348/UV Test Set at every opportunity. The resolution cannot be accurately measured without the test set.

The following procedures are designed to check the performance of the image intensifier.

a. Setup

NOTE:
The resolution test must be performed in a darkened area. Your eyes must be dark-adapted to perform this test. Review the following test procedure before entering the dark area. NOTE:
Expect cosmetic blemishes, such as chicken wire, black spots, and fixed-pattern noise, to stand out while viewing through the TS-4348/UV Test Set when it is on the high light level. This is acceptable. NOTE:
The rejection of any NVG for cosmetic defects must be based on an outdoor evaluation and not the TS-4348/UV Test Set.

b. Low Light and High Light Resolution Test Procedure

1. Place the HIGH/LOW switch on the test set to the LOW position.
2. Turn off the room light and let your eyes adjust to the dark.
3. Turn on the test set by pressing the knob inward.
4. Turn on the goggles and insert them into the test port on the test set.
5. Look through the goggles and view the projected pattern. If necessary, focus the eyepiece lens and then the objective lens to obtain the sharpest image.
6. The NVG goggles must be able to resolve Group 2, Element 2, under low light conditions to pass the test. If the NVG does not pass the test, return it to maintenance for repair.
7. Flip the HIGH/LOW switch to the HIGH position.
8. Again, look through the goggles and view the projected pattern. If necessary, refocus the objective lens and then the eyepiece lens to obtain the sharpest image.
9. The NVG must be able to resolve Group 3, Element 5, under high light conditions to pass the test. If the goggles do not pass the test, send them to a higher level of maintenance for repair.
10. Look for flashing, flickering, or other unstable behavior of the image intensifier. Also check the image intensifier for other operational defects described in paragraph 2.2.3.

NOTE:
For a pattern to be resolvable, three vertical bars and three horizontal bars must be visible. NOTE:
When using the TS-4348/UV Test Set, you are not viewing the entire image intensifier. Therefore, operational and cosmetic inspections must be done without the test set as specified in paragraph 2.2.3.

2.2.3. INSPECTION CRITERIA FOR PROPER IMAGE INTENSIFIER OPERATION

a. General
As directed in the Preventive Maintenance Checks and Services table, image intensifier operation must be checked before each mission. This section provides information for the operator concerning what to look for, how to look for it, and how to determine if the NVG should be returned to the maintainer.

CAUTION:
Perform the following inspection in the dark.

To perform this inspection, attach the goggles to the head mount and turn the power switch to the ON position. Look through the goggles and view the image.

There are two groups of defects you may encounter: operational defects and cosmetic blemishes. Operational defects are an immediate cause to reject the NVG. Cosmetic blemishes are not a cause for rejection unless they become severe enough to interfere with the ability to perform the mission.

b. Operational Defects

These defects relate to the reliability of the image intensifier and are an indication of instability. If identified, they are an immediate cause for rejecting the NVG. They include shading, edge glow, flashing, flickering, and intermittent operation.

(1) Shading. If shading is present, you will not see a fully circular image. Shading is very dark and you cannot see an image through it. Shading always begins on the edge and migrates inward eventually across the entire image area. Shading is a high contrast area with a distinct line of demarcation. Return the NVG to the maintainer.

NOTE:
Make sure the shading is not the result of improper eye-relief adjustment.

(2) Edge Glow. Edge glow is a bright area, sometimes sparkling, in the outer portion of the viewing area. To check for edge glow, block out all light by cupping a hand over the objective lens. If the image intensifier is displaying edge glow the bright area will still show up. Return the NVG to the maintainer.

(3) Flashing, Flickering, or Intermittent Operation. The image may appear to flicker or flash. If there is more than one flicker, check for loose battery cap or weak batteries. If weak or loose batteries are not the problem, return the NVG to the maintainer.

c. Cosmetic Blemishes

These are usually the result of manufacturing imperfections that do not affect intensifier reliability and are not normally a cause for rejecting an NVG. However, some types of blemishes can get worse over time and interfere with the ability to perform the mission.

(1) Bright Spots. A bright spot is a small, nonuniform, bright area that may flicker or appear constant. Not all bright spots make the NVG rejectable.

(2) Emission Points. A steady or fluctuating pinpoint of bright light in the image area that does not go away when all light is blocked from the objective lens.

(3) Black Spots. These are cosmetic blemishes in the image intensifier or dirt or debris between the lenses. Black spots are acceptable as long as they do not interfere with viewing the image.

(4) Fixed-Pattern Noise. This is usually a cosmetic blemish characterized by a faint hexagonal honeycomb pattern throughout the viewing area that most often occurs at high light levels or when viewing very bright lights.

(5) Chicken Wire. An irregular pattern of dark thin lines in the field-of-view either throughout the image or in parts of the image area. No action is required unless it interferes with the operator's ability to view the image or to perform the mission.

Flip Up and Power Off Function

In the startup state, press the power encoder switch five times. The indicator in the left eyepiece blinks five times and turns on the power off function. When the night vision device is turned over by more than 90°, the device stops working. When the device is turned back to the working angle, it restores power supply and works normally.

To turn the function off, in the flip-up shutoff state, press the power encoder switch five times. The indicator in the right eyepiece blinks five times, and the flip-up power off function is shut down.

Focus Adjustment

In the power-on state, turn the focusing hand-wheel, which can adapt to the observation of the target from 250 mm to infinity.

NOTE:
The sharpest image will be observed only when the objective lens and eyepiece lens are properly focused.

Pupil Distance Adjustment

Each barrel of the goggles can be pushed together, or can be opened to both sides to adapt to different pupil distance requirements.

NOTE:
Any readjustment of eye relief requires readjustment of the diopter.

According to the user's pupil distance, when adjusting the pupil distance of the goggles to the appropriate position, rotate the pupil distance adjustment positioning screw just to the bottom, so that the goggles pupil distance position suitable for the user can be positioned and quickly reset next time.

Table 2.3. Field of View and Positioning Adjustment
Field of View	Remarks / Correction
Best calibration	Best Calibration
Eye point distance is too long	Fix pre and post adjustment
Eye point distance is too short	Fix pre and post adjustment
Pupil distance setting is too narrow	Fix pupil distance adjustment
Pupil distance setting is too wide	Fix pupil distance adjustment
Positioning is too high	Fix height adjustment
Positioning is too low	Fix height adjustment

Manual Gain Adjustment

The brightness gain is adjusted by rotating the power encoder switch. The brightness gain decreases by clockwise rotation and increases by counterclockwise rotation. The brightness gain adjustment value can be remembered by restarting after power failure.

Check Whether the Goggles are Working Properly

Check the working status of the goggles in daylight or under strong light: remove the shroud on the goggles, cover the lens cap, press the power encoder switch in the direction of the goggles for 2 seconds, and observe whether the goggles work normally from the direction of the eyepiece. When it is necessary to shut down, press the power encoder switch in the direction of the goggles for about 3 seconds to shut down. Check the status of the goggles in the night in the same way.

Low Power Indicator

The LED under-voltage indicator light is red in the eyepiece of the goggles, and it has the low-voltage continuous flashing alarm function. After the blinking alarm, the goggles can still work normally for about 0.5 hours. After the goggles start to alarm, the battery should be replaced in time.

ASSEMBLY AND PREPARATION FOR USE

2.3.1. UNPACKING

The following steps must be accomplished prior to each mission where the NVG is used.

1. Check contents for completeness.
2. Remove the carrying case. Open carrying case, remove NVG, and check contents for completeness.
3. Inspect the goggles for obvious evidence of damage to optical surfaces, body, eyecup, power switch, battery cap, etc. Ensure that all optical surfaces are clean and ready for use. Clean with lens paper.

2.3.2. INSTALLATION OF BATTERY

CAUTION:
To protect the image intensifier, keep the objective lens cap on when the goggles are not in use or when using the goggles in daylight conditions.

The NVG operates with one CR123 battery.

TABLE 2.4. ESTIMATED BATTERY LIFE
Battery Type	Negligible IR Source Usage	IR Source Usage 10% of the Time
CR123	60 Hrs	55 Hrs

CAUTION:
Make certain the power switch is in the OFF position before installing the battery. NOTE:
The battery must be removed when transporting or storing the goggles. The battery reverse contact night vision device does not work and will not cause damage to the product, and the battery polarity direction should be confirmed when installing the battery.

Take out a battery from the battery storage place of the carrying bag and check whether the battery has expansion, leakage, etc. Do not install defective batteries into the goggles. Open the battery cover according to the positive and negative electrode marks on the goggles, put the battery into it, and tighten the battery cover.

2.3.3. INSTALLATION OF EYECUP

1. Carefully press the eyecup over the end of the eyepiece lens.
2. Rotate the eyecup into the proper viewing position. Adjust for best fit. The eyecup must seal around your eye and prevent the green glow from escaping.

2.3.4. INSTALLATION AND ADJUSTMENT OF HEAD MOUNT

NOTE:
Do not don the head mount while the goggles are attached.

1. Prior to donning the head mount, loosen the four ends of the chinstrap approximately two inches from the sliding bar buckles.
2. Snap the front and rear snaps in place.
3. With both hands grasp the neck pad and pull the harness over your head and the neck pad down to the back of your neck.
4. Holding the chin cup in position on the chin, adjust both sides of the chinstrap until you feel light pressure against your chin. Do not tighten.
5. Maintain the position of the chin cup and remove any slack from the chinstrap. Do not tighten.
6. Ensure that the cross-strap is not twisted and remove slack by adjusting the vertical adjustment at the neck pad.
7. Adjust chinstrap and vertical adjustment until the chin cup and headband are in a comfortable but firm position.
8. Refer to paragraph 2.4.2 for operating procedures.

NOTE:
After installing the goggles, minor strap adjustments may be necessary to achieve comfort.

2.3.5. INSTALLATION OF HELMET MOUNT TO HELMET

NOTE:
Do not don the head mount while the goggles are attached.

1. Remove the helmet mount from the carrying case.
2. Press the release to remove the mount from the helmet mount bracket.
3. Make sure the strap is laced onto the helmet mount bracket as shown.
4. With catch in the forward most position, place the strap over the top of the helmet center.
5. Hook the rear bracket on the center of the back of the helmet and lay the strap with helmet mount bracket over the top of the helmet.
6. Hook the helmet mount bracket in the center of the front lip of the helmet and hold it in place.
7. With the buckle lever open, take up the slack in the strap using the catch. Close the buckle lever.
8. Disengage the nape strap latch on the left side of the nape strap.
9. Don the helmet. Do not fasten the helmet chinstrap.
10. Engage the nape strap at the nape strap latch. Tension the nape strap for a stable fit, then install and tension the helmet chin strap. The brow of the helmet should be parallel to the ground and the helmet stable on the head.
11. Insert the top edge of the mount under the keeper on the helmet mount bracket and rotate downward until the latch engages. To release the mount, press the release and pull forward and down.

2.3.6. Installation of Helmet Mount to Goggles

The connection of the goggles to the helmet mount is done through a dovetail slot. Align the dovetail slots of the goggles with the mounting slots of the bracket, make them fit and press until they snap into place.

Connect the External Battery Box to the Cable and Goggles

1. Align the red dot on the cable connector with the red dot on the external battery box socket, then insert the connector into the socket until it is locked.
2. Align the other red dot on the cable connector with the red dot on the goggles socket, then insert the connector into the socket until it is locked.

WARNING:
Forcing the cable to the external battery box without alignment can damage the power plug or socket. Do not twist the connector while installing the cable.

The cable will automatically lock into place when the external battery box is properly connected to the goggles. Pull the shaft ring of the cable connector outward when disconnecting. Do not pull the cable.

Connect the External Battery Box to the Helmet

Use Velcro 1 to glue battery box 2 to the back of helmet 3.

Put the installed unit on the user's head, adjust the helmet to a suitable and comfortable position, adjust the pupil distance to a suitable position, and adjust the night vision goggles helmet according to parameters of helmet mount to make the unit in a suitable position.

When the goggles are not in use for the time being, they can be turned over to the standby position through the helmet mount, and the goggles can be closer to the helmet by increasing the pupil distance.

The goggles can be used as a single item. When attached to the helmet, one of the monocular tubes can be pulled sideways and up away from the eye, leaving the other monocular tube in place.

NOTE:
The sharpest image will be observed only when the objective lens and eyepiece lens are properly focused.

Disassembly of the Goggles

1. Hold the unit with one hand, unplug the external cable so that the cable is detached from the host, press the release button, remove the main unit, open the battery cover, take out the battery, screw on the battery cover, put the cap on, and put it in the carrying bag.
2. Press the installation/release button, take off the helmet mount of the night vision goggles, adjust the front and back of the helmet mount to the most backward position, turn it over to the standby state, and put it into the carrying bag.
3. Remove the external battery box and take out the battery, remove the external cable and put it into the carrying bag.
4. The position of the main unit components and spare accessories into the carrying bag is shown below.

OPERATING PROCEDURES

This section contains operating procedures for using the NVG as hand-held, head mounted, and helmet mounted goggles. Prior to operating the goggles, make certain that all the steps in Assembly and Preparation for Use have been read and performed.

2.4.1. HAND-HELD OPERATION

Operate the goggles only under darkened conditions or use the objective lens cap to cover the objective lens for daylight conditions.

1. Ensure that the battery is installed.
2. Press the knob inward to turn the power on.
3. Rotate the diopter adjustment for the clearest view of the image intensifier screen.
4. Focus the objective lens while observing an object until the sharpest image is obtained.

NOTE:
The sharpest image will be observed only when the objective lens and eyepiece lens are properly focused.

2.4.2. HEAD MOUNTED OPERATION

CAUTION:
Operate the goggles only under darkened conditions or use the lens cap to cover the objective lens for daylight conditions.

1. Ensure that the battery is installed.
2. Don the headmount per instructions in paragraph 2.3.4.
3. Align the head mount or helmet mount latch to the head mount socket. Insert the helmet fixture into the socket of the mount.
4. Set your eye relief by depressing the eye relief adjustment and move the goggles back toward your eye until the eyecup comfortably seals around the eye.
5. Turn the goggles on.
6. Readjust the vertical adjustment of the head mount until the goggles are properly aligned with your eye.
7. Rotate the diopter adjustment for the clearest view of the image intensifier screen.
8. Adjust the eye relief distance by pressing the eye relief adjustment and sliding goggles fore or aft to obtain a full field of view of the image. Reset the diopter adjustment for the best image.
9. Adjust the objective lens focus while observing an object until the sharpest image is obtained.
10. Adjust the interpupillary adjustment to be in line with the distance between your eyes. Use the side knobs as illustrated in Figure 2.22. This setting should remain set for the user.
11. When you flip the NVGs up over the head mount, the NVGs will automatically power off. When you flip the NVGs down into viewing position, they will power back up automatically.

NOTE:
To make it easier to align the goggles, eyecup, and eyepiece lens to the eye, depress the eye relief adjustment and slide the head mount socket all the way forward before attaching the goggles. NOTE:
The sharpest image will be observed only when the objective lens and eyepiece lens are properly focused. NOTE:
Any readjustment of eye relief requires readjustment of the diopter.

2.4.3. Helmet Mounted Operation

CAUTION:
Take some precaution when using or handling the helmet mount. CAUTION:
Do not use excessive force when changing the up/down position of the NVG.
Do not drop or throw the helmet with the helmet mount attached to it.
With the goggles in the flipped up position, do not flick the goggles down by shaking the helmet.
All other services require returning the helmet and helmet mount to unit maintenance for direct mounting of the bracket via the helmet screws. NOTE:
The helmet mount provides two positions for the user to position the NVG: flipped down for viewing and flipped up when the NVG is not needed for immediate use.

1. Ensure that the batteries are installed and don the helmet mount.
2. By pressing the release button, the goggles can be detached from the helmet mount.
3. By locking or releasing the helmet button, the night vision goggles mount can be locked or released.
4. By pressing the lock or release mode button, the lock or release mode of the mount can be selected.
5. By pressing the front and rear adjustment button, front/back adjustment of the goggles is allowed. Release the button to fix the position.
6. By adjusting the locking button up and down, the operation can realize upward and downward adjustment and locking of the goggles.
7. When the host is connected, through the host flip button, the host can be flipped up to the standby position by the mount.
8. The tilt angle of the host can be accurately adjusted through the tilt button.

NOTE:
The sharpest image will be observed only when the objective lens and eyepiece lens are properly focused. Any readjustment of eye relief requires readjustment of the diopter.

TABLE 2.5. TECHNICAL PARAMETERS
External dimensions (working)	103 mm (L) x 69 mm (W) x 70 mm (H)
Weight (helmet mount)	170 g
Height adjustment	22 mm
Front and rear adjustment	27 mm
Tilt adjustment	0 to 14°
Flip angle	130°

2.4.3.1. Eyepiece Distance Adjustment

In certain circumstances you may want to use only one eye to look through the NVG, either to retain natural night vision in one eye or to look through a sight affixed to your weapon.

1. Select the eyepiece you would like to move out of the field of view with the hand that is on the same side as the eyepiece.
2. Gently push it upwards with your hand so that it locks in position.
3. The flipped-up eyepiece will turn off automatically in order to prevent light bleed from the eyepiece.
4. Conduct your maneuver as normal.
5. By lowering the previously flipped-up eyepiece, it will power on again.

2.4.4. IR SOURCE OPERATIONS

WARNING:
The IR source is a light that is invisible to the unaided eye for use during conditions of extreme darkness. However, the light from the IR source can be detected by the enemy using night vision devices.

Infrared auxiliary light on: in the startup state, press the power encoder switch twice. The light in the left eyepiece is steady on, the light in the right eyepiece flashes twice and then turns off, and the infrared auxiliary light turns on.

Infrared auxiliary lighting off: in the case of infrared auxiliary lighting on, press the power encoder switch twice. The constant light indicator in the left eyepiece turns off, and the infrared auxiliary light is off.

NOTE:
The purpose of the IR source is for viewing at close distances up to 3 meters when additional illumination is needed.

1. Turn the power switch knob and rotate clockwise to the IR position. With the goggles held to the eye, observe that a red light appears in the eyepiece. This indicates that the IR source is operating.
2. Auto Mode: The automatic mode is different from the IR mode, and the automatic mode starts the environment detection sensor. It can detect environmental luminance in real time and work with reference to illumination control systems. Under extremely low or extremely dark environment, the system will automatically turn on infrared auxiliary lighting. When environmental illumination can meet normal observation, the system automatically turns off IR, and when ambient illumination reaches 40-100 Lux, the whole system is automatically shut down to protect the photosensitive core components from damage by strong light.

2.4.4.1. Auxiliary Battery Installation (optional)

NOTE:
Projected runtime or battery life can be increased when the auxiliary battery is used.

1. Install four CR123 batteries into the battery holder.
2. Attach the battery holder to the rear of the helmet or headgear.
3. Run the power cord from the battery holder to the NVG.
4. Plug the power cord into the NVG.
5. Turn the NVG on.

PREPARATION FOR STORAGE

1. Shutdown
   • Press the knob to turn the goggles off.
   • Remove the goggles from the head mount or helmet mount.

WARNING:
Do not carry batteries in pockets containing metal objects such as coins, keys, etc. Metal objects can cause the batteries to short circuit and become very hot.

Packaging after use

1. Remove battery cap and remove battery.
2. Inspect the battery housing for corrosion or moisture. Clean and dry if necessary.
3. Replace the battery cap.
4. Install objective lens cap.
5. Place the goggles into the shallow pocket of the carrying case.
6. Place the carrying case into the shipping and storage case.
7. Return to the storage area.

NOTE:
Prior to placing NVG into the carrying case, ensure NVG and case are free of dirt, dust, and moisture. NOTE:
The goggles and helmet mount should not be left on the helmet when the helmet is removed.

OPERATION UNDER UNUSUAL CONDITIONS

2.5.1. OPERATION IN DUSTY OR SANDY AREAS

CAUTION:
Operation in dusty or sandy areas can pit and scratch the optical elements and damage the mechanical components unless the precautions given below are observed.

1. Avoid pointing the goggles into the wind unless necessary for operation.
2. Keep the carrying case closed unless removing or replacing items.
3. Ensure that all dust and sand is removed from the NVG and carrying case after operation.

2.5.2. OPERATION IN RAINY OR HUMID CONDITIONS

CAUTION:
Operation in rainy or humid conditions can cause corrosion and deterioration of the NVG unless the precautions given below are observed.

1. Keep the carrying case, and shipping and storage case closed unless removing or replacing items.
2. Dry the goggles, mounts, and accessories after exposure to rain or high humidity and before storage. This will prevent mildew from forming in the case.
3. Do not store goggles in a wet carrying case or a wet shipping and storage case.

2.5.3. OPERATION IN SALT WATER AREAS

After exposure to salt water, clean the NVG.

2.5.4. OPERATION IN NUCLEAR, BIOLOGICAL AND CHEMICAL (NBC) ENVIRONMENTS

WARNING:
Do not use contaminated eyecup. They must be replaced.

1. Decontamination - Wear a protective mask while using NVG after the decontamination process.
2. Hardness - Do not use DS-2 for decontaminating the NVG. To decontaminate, use 5% sodium hypochlorite and rinse with hot 158°F soapy water.

MAINTENANCE INSTRUCTIONS

3.1. LUBRICATION INSTRUCTIONS

No lubrication is required.

3.2. TROUBLESHOOTING PROCEDURES

3.2.1. TROUBLESHOOTING

This manual cannot list all the malfunctions that may occur, all the tests and inspections needed to find the fault, or all the corrective actions needed to correct the fault. If the equipment malfunction is not listed or actions listed do not correct the fault, notify your maintainer.

The task is limited to the replacement of the battery, the shield, the viewing accessories, and the eyecup. If replacement according to these procedures still cannot restore the unit to normal work, it should be delivered to the special maintenance department for inspection and repair.

Malfunction	Test or Inspection	Corrective Action
1. Goggles fails to activate.	A. Visual. Turn power switch to OFF position and then ON. Check for defective, missing or improperly installed battery. B. Shield not removed. C. The image intensifier tube is damaged.	Replace battery or install correctly. Remove the shield. Deliver to the maintenance department for inspection and repair.
2. IR source fails to activate.	In a dark location with system turned on, activate IR source. Visually check IR source operation; scene should brighten.	If IR source still fails to activate, refer to higher level of maintenance.
3. IR source indicator fails to activate.	Visual.	Refer to higher level of maintenance.
4. Poor image quality.	Check objective lens or eyepiece lens focus. Check for fog or dirt on objective lens or eyepiece lens. Check brightness adjustment. Check whether viewing accessory is installed and undamaged.	Refocus. Clean lens surfaces. Adjust the brightness knob to increase brightness. Install appropriate viewing accessories. Replace scratched or cracked viewing accessories.
5. Light visible around eyecup.	Check eye relief distance. Check eyecup for resiliency.	Readjust for proper eye relief distance. If eyecup is defective, refer to higher level of maintenance.
6. Diopter adjustment cannot be made.	Check to see if the diopter adjustment is bent or broken.	If damaged, refer to higher level of maintenance.
7. Battery cap difficult to open.	Visually inspect for the presence of an O-ring. Check for damaged battery cap.	If O-ring is missing, refer to higher level of maintenance. If damaged, refer to higher level of maintenance.
8. Head straps cannot be tightened.	Check for defective buckles, fasteners or straps.	If damaged, refer to higher level of maintenance.
9. Headmount or helmet mount socket and headmount / helmet mount adapter latch does not catch.	Check socket or latch for dirt. Check socket or latch for damage.	Clean socket and latch. If damaged, return either headmount or helmet mount socket and adapter to higher level of maintenance.
10. Helmet mount will not tighten to helmet.	Inspect mounting hardware for damage.	If damaged, refer to higher level of maintenance.
11. If damaged, refer to higher level of maintenance.	Visual.	Refer to higher level of maintenance.
12. Goggles do not cut off when exposed to high light.	Perform the test under daylight or bright room light. Place the objective lens cap on the objective lens. Turn goggles ON and observe that it cuts off within 70 ±30 seconds. Turn goggles OFF and then ON to reenergize.	If damaged, refer to higher level of maintenance.

3.3. OPERATOR'S MAINTENANCE PROCEDURES

3.3.1. CLEANING THE NVG

CAUTION:
The goggles are a precision electro-optical instrument and must be handled carefully.
Do not scratch the external lens surfaces or touch them with your fingers. Avoid falling, collision and exposure to the sunlight.
Clean goggles with water if necessary and dry thoroughly. Clean lenses with lens paper.
Wear a shield when not in use.

The goggles should always be kept dry and clean. If you find they are dirty, you should carefully wipe them. Before the goggles are stored for a long time, a comprehensive inspection should be carried out to confirm that everything is normal, and the switch should be placed in the off position.

The combination parts that affect the sealing of the goggles are glued with sealing substances, which shall not be wiped away to avoid moisture entering the interior of the goggles.

The desiccant in the packaging box, after a period of use, will inhale moisture and lose the drying effect. If the color of the desiccant changes, the desiccant can be baked in a vessel until the moisture evaporates and it returns to natural color, after which it can continue to be used.