PVS-31 PRO User Manual

User Manual
PVS-31 PRO
Gen 2+ autogated dual tube analog night vision binocular with manual gain, 50 degree field of view, G24 helmet mount and external battery pack.
Read this before you take the unit out. The five rules below prevent almost every failure we see. With two tubes there is twice the value at risk from one careless moment in daylight.
The five rules
- Never point it at the sun, a laser, or any bright light while powered on. This burns both tubes permanently and is not covered by warranty.
- Keep the lens caps on whenever you are not looking through it, especially in daylight.
- Take the batteries out for storage, from the unit and the external pack.
- Do not open the housing. No user serviceable parts, and it voids your warranty.
- Do not touch the glass with your fingers.
01Specifications
| Configuration | Dual tube binocular |
| Image intensifier | Gen 2+ autogated |
| Phosphor screen | P43 or P45 |
| Field of view | 50 degrees, plus or minus 2 |
| Magnification | 1x, plus or minus 0.05x |
| Optical distortion | 2 percent or less |
| Relative illumination | Greater than 70 percent |
| Gain control | Manual |
| Focus range | 250mm to infinity |
| Diopter adjustment | +2 to -6 |
| Eye relief | 25mm or greater |
| Exit pupil | 14mm or greater |
| Power | Onboard 1x CR123A or 1x AA, plus external pack taking 4x AA |
| Infrared illuminator | 930nm |
| Rollover detection | Automatic. Powers off when flipped up or rotated sideways |
| Safety features | Low voltage alarm, strong light protection |
| Runtime | 15 hours onboard, up to 75 hours with the external pack |
| Weight | 450g or less without batteries |
| Operating temperature | -20C to +45C |
| Water resistance | IP67 |
02In The Box
- PVS-31 PRO binocular
- G24 helmet mount
- External battery pack
- Power cable
- Eyecups, pair
- Carrying case

Check this against your order confirmation as soon as the parcel arrives. If anything is missing or damaged in transit, email us straight away and keep the packaging.
03Know Your Unit

- 1Objective lenses
- 2Interpupillary distance knob
- 3Eyepieces and diopter rings
- 4Power switch and gain knob
- 5External power cable socket
- 6Dovetail mounting interface
- 7Eyecups
- 8Infrared illuminator
- 9Ambient brightness sensor
- 10Battery cap
04Power
Run it from the onboard cell alone for about 15 hours, or add the external pack for up to 75. Most people wear the pack on the rear of the helmet, where it also balances the weight on your neck.
Onboard cell

- Unscrew the battery cap anticlockwise and remove it.
- AA cell: insert it directly, matching the orientation marked on the housing.
- CR123A cell: fit the supplied adapter onto the cap first, then insert.
- Screw the cap back down fully. That seal is what gives you the IP67 rating.
External battery pack

- Fit 4x AA cells into the pack in the marked orientation.
- Connect the cable from the pack to the socket on the binocular.
- Route the cable so it cannot snag and secure any slack.
05Mounting


- Slide the dovetail into the G24 helmet mount in the direction of the arrow until it locks.
- Set the fore and aft position so the eyecups sit close to your eyes without pressing on your face, then lock it.
- Set the height and tilt so the image is centred when you look straight ahead.
- Pull on the unit to confirm it is locked before you move.
- Check the battery cable is clear of the mount and cannot be pulled when you turn your head.
06Operation
- Power on. Turn the switch to ON. Turning further clockwise increases gain.
- Set your IPD first. Adjust the knob until the two circles merge into one clean circle with no dark crescent at either edge.
- Set the diopters. One eye at a time, rotate each eyepiece ring until that screen's grain is sharp. Set once and leave it.
- Focus the objectives. Rotate each objective ring until the scene is sharp. Refocus when your working distance changes.
- Set gain. Use the lowest setting that gives you a usable picture.
- Infrared, only if you need it. In near total darkness press the switch once. Press again to turn it off.
- Power off. Turn the switch to OFF. Remove the batteries if you are storing the unit.


Set IPD before anything else
If the two circles are not merged into one you will fight the unit the whole time you wear it, and it causes eye strain and headaches. Correct IPD gives a single crisp circle with no shadowing at the edges.
Infrared gives away your position
The beam is invisible to the naked eye but it is a floodlight to anyone else running night vision. Use it only when the unit cannot form an image on its own.
The indicator light means two different things
There is one indicator and it does two jobs. Learn the difference.
| Indicator | Meaning | What to do |
|---|---|---|
| Solid | Infrared illuminator is ON | Nothing. Press the switch again to turn it off. |
| Flashing | Battery is low | Roughly two hours left. Swap the battery or connect the pack. |
Automatic protections
| Feature | Behaviour |
|---|---|
| Rollover shutoff | Powers down when flipped up or rotated sideways past 90 degrees, and resumes in the working position. Hold the switch more than 5 seconds to disable. |
| Strong light protection | On by default at power up. Protects the tubes when bright light enters the view. Hold the switch more than 5 seconds to disable. |
07Care And Storage
- Blow loose grit off the lenses before any wipe
- Use lens tissue with lens fluid, circular motion from the centre out
- Wipe the body with a barely damp cloth, then dry it
- Store near 25C, humidity under 40 percent
- Store with batteries removed and caps fitted
- Use paper towel, clothing or any abrasive cloth on the glass
- Wipe the demist shield while it is wet
- Wipe grit across the lens. That is how coatings get scratched
- Store it damp, or anywhere hot
- Leave cells in the external pack during long storage
08Troubleshooting
| Symptom | Check | Action |
|---|---|---|
| Will not power on | Batteries onboard and in the pack. Cable seated at both ends. | Replace or reseat the batteries. Reconnect the cable. |
| Powers off by itself | Is it flipped up or rotated sideways? | That is the rollover shutoff working. Return it to the working position. |
| Dark crescent at the edge | Interpupillary distance. | Adjust the IPD knob until the image forms one complete circle. |
| One side sharper than the other | That side's diopter and objective. | Set each side independently, diopter first, then objective. |
| Indicator flashing | Battery charge. | Low battery. Roughly two hours left. |
| Dim or grainy image | Gain setting and available light. | Raise gain, or switch on infrared in near total darkness. |
| Runtime much shorter than expected | Is the external pack connected with fresh cells? | Onboard alone gives roughly 15 hours. Fit fresh cells in the pack. |
09Warranty And Support
Your unit is covered for 3 months from delivery as standard. If you bought Operator Care, coverage extends to 12 months. We sell direct, so warranty and support come straight from us with no dealer in between. Have your order number ready.
Not covered
- Tube damage from the sun, lasers or other bright light sources while powered on
- Any damage after the housing has been opened
- Corrosion from batteries left in during storage
- Physical damage from drops or crushing
Night Operators PVS-31 PRO user manual, revision 1.1. Specifications may change without notice as the product is updated. The current version of this manual is always available at nightoperators.com.