Tag: JRH PVS14
Why Purging a PVS14 is Important
When properly assembling a night vision device, whether it’s a PVS14, dual tube set etc. a proper pressure test and nitrogen purge is very important.
A vacuum is pulled on the device. A gauge on the purge set is pumped up and left in place for a short period of time. During this time, there should be no leakage- as seen on the set by the needle falling rapidly. This is another step in confirming proper assembly and that the components are up to the task.
Nitrogen is then flushed into the night vision system. This is done to protect the optics from getting foggy in high humidity situations- similar to how your car windshield will fog up on the inside during inclement weather.
Another advantage of proper nitrogen purging is that if there remains any “debris in field” aka small trash inside the unit from assembly, the pressure of the purge will often show this. Pepper speck, actual spots, small lines in the tube and other tube cosmetic issues won’t move when purged, trash/”debris in field” usually will. This helps the technician spot any potential problems and then the unit is disassembled and cleaned again and the whole process starts over purging the unit again. We nitrogen purge every night vision device assembled here at JRH Enterprises.
A common question regarding nitrogen purging is do you have to do it regularly? Unless the unit is damaged, disassembled, etc. purging regularly isn’t necessary. If you start to see fogging after the unit is dropped or mishandled, then certainly it’s time to get it purged again.
On any NV units produced by JRH Enterprises (will have a data plate on the side of the device similar to the ones in the picture below), we are happy to purge the unit for you again. This is free of charge (customer pays shipping). Email us with your System number/serial number on the side of the unit (see pic).
How to pick out a PVS14
Below is a quick look at how to pick out a PVS14 for new users. Sometimes the “research” people do on night vision literally can just lead them in circles. Worse yet they get advice from people who’s circumstances or uses may not be similar to yours.
“What do the numbers and pictures mean?”
Since every single night vision tube is different, there are natural variations in tube performance and cosmetics from one tube to another. One tube may have several black spots, another clean, one tube may have low Ebi, another higher Signal to noise ratio but slightly higher Ebi. Which to choose?
At this point I would remind you that we are never more than a phone call or email away. And even after you read this, or “just aren’t sure” that what you are looking at is best for YOU, just give us a quick call. Your under no obligation to buy. We do this every day, avail yourself of 33 years of experience! 912.375.1480 direct email robert@jrhenterprises.com
FOM is a term you will hear a lot about. It stands for Figure of Merit. Basically the Signal to noise ratio specification is multiplied by the Resolution of the tube to get this number. For example a tube with a Signal to noise ratio of 30 and a Resolution of 72 would have a figure of merit of 2,160 and all other specification aside, would perform more than adequately for 99% of the lighting conditions most people will face. The higher the FOM level- in general- the more performance you can expect from the tube. This means greater light gathering capability which helps in extreme low light situations.
We have 33 years in the night vision industry, please feel free to reach out directly with any questions you have.