By looking at the first four digits of the serial number, you can determine the manufactured date. For example, if it says 5123, that means it was built in 2005, on the 123rd day of that year. A new detector has a 2-year transferrable warranty, beginning the date you purchased it and the dealer registers the warranty. If you buy a used detector that has no record of the warranty being registered, (and no warranty paper to send in) Whites considers the two-year warranty to begin on the manufactured date.
Even though you bought yours new, don't be surprised if it was actually built 8 or 10 months ago. After being built, they are stored in Whites warehouse. When a distributor orders one, Whites sends it to the distributor via UPS. It may get loaded and unloaded onto 4 or 5 trucks before it finally arrives at the distributor. Then, the distributor stacks them in his warehouse. When a dealer requests one, it may get loaded and unloaded onto 3 or 4 more UPS trucks before it gets to the dealer. Then the dealer stacks them in his warehouse or shop until it sells. If you pick it up at the dealership, chances are it was handled a dozen times. And you have to realize that not everyone handles them as electronic instruments should be handled. If you bought it over the net, it was shipped to your home, once again being loaded and unloaded from several trucks. It is not hard to imagine that it may have been dropped once or twice since it was built. Whites boxes are sturdy. But I think their packing could be better.
Since yours is new, I doubt that it is static. That is easily determined by wiping a dryer sheet over the front of the screen. If you don't have a dryer sheet, use a soft cloth and see if the needle moves when you wipe across it. It more than likely needs to be recalibrated or rescaled. If the dryer sheet don't work, I suggest you call Whites and see how they want to handle it. You may be able to take it back to your dealer for recalibration, or they will let you try to recalibraate it yourself. Just make sure that your "working on it" yourself does not void the warranty. HH Randy