Selecting a thermal scope for your rifle can be a difficult and confusing task. The internet is a wonderful source of information but there is little to control the validity of that information. Today, many thermal rifle scopes are listed from a variety of companies. There are also many foreign knock off type scopes or low cost "commercial" scopes that have questionable long term value. The true thermal weapon sights are military grade systems designed for the rough conditions of combat and law enforcement scenarios. If you are going to spend thousands of dollars on a precision thermal sighting system you should invest in a quality piece that will work now and for a long time to come.
While there are many thermal scopes out there, they all fall into two basic categories. There are stand alone thermal rifle scopes and there are clip on thermal scopes. The stand alone thermal weapon sight is much like your traditional optical daytime rifle scope. The stand alone scope mounts to your rail and has an internal reticle that can be adjusted for windage and elevation in order to "zero in" your rifle. Military grade stand alone thermal scopes are very rugged and meant to give you years of service. The most popular of this type is the US Army TWS (Thermal Weapon Sight) program. The drawback to a dedicated thermal scope is that once it is zeroed in it is pretty much dedicated to that weapon. For example, if you wanted to take off the thermal and put on an optical scope for daytime shooting then you would have to sight in your daytime scope and then once again sight in the thermal scope when you put it back on. The other option is to have a dedicated daytime weapon and nighttime weapon. This may not be a problem for some civilian applications but can pose a real issue in military environments. Enter the innovation of the Clip On Thermal Rifle Scope.
Dedicated thermal rifle scope.
Clip on thermal scopes were developed for the US Military forces to answer the need to have a single weapon that can be used day or night without the need to rezero. A clip on scope is an amazing piece of optical engineering that allows you to "clip on" a thermal scope in front of your daytime optic. This turns your standard optical scope into a thermal scope. When you are done with thermal shooting take off the clip on scope and you are back to your daytime optic. The magic part is that you do not have to rezero your weapon at any time. As long as your daytime scope starts off on target then the clip on will be on target. This is the hot new technology and the way forward. You only need a single weapon and you get to use the shooting system that you are most comfortable with but now it has thermal capability.
Clip on thermal scope with Trijicon ACOG Daytime scope.
Utilizing superior thermo night vision technology coupled with uncooled FPA sight and scope FLIR technology, SPI's Thermal weapon sights are a completely passive infrared weapon sighting system which allows users to identify the heat signatures of individuals or objects day or night and in rain, fog and smoke. No external flash infrared (IR illuminator) light source is required, and the unit may be used in complete darkness or broad daylight. When viewed through the scopes, heat-emitting objects such as humans and recently-operated vehicles stand out dramatically against their surroundings, defeating camouflage and other methods of visual concealment. Built to rugged standards, The FLIR Thermal weapon sight perform flawlessly. Our FLIR thermal weapon sights are a shock and water-resistant sight that will withstand the forces generated by repeated recoil. The quick-detachable mount allows fast attachment to Mil-Std-1913 Pica tinny rails and weapon receivers. Once sighted-in to a particular weapon, the sight may be interchanged with other SPi optical and electro-optical sights zeroed for the same weapon in a matter of seconds and without noticeable change in point of impact. The electronic reticle allows precise targeting of hostile threats. The SPiThermo sights operate on three lithium AA batteries and has auxiliary power ports for operation on AC electrical outlets or vehicle cigarette lighters. A vision video output port allows the image to be displayed on an external video monitor or recorded by flash video recorder. When used solely as an observation device, the unit may be operated hand-held or tripod mounted. Weighing less than three pounds, the FLIR thermal camera is a compact yet powerful tool for Security, law enforcement, EOD, battle lab, arsenal, US government labs & US Militaryprofessionals.