Those who know me will be aware that I am a long term user, collector and repairer of thermal imaging cameras. This thread details my latest acquisition..... the AGA 680 Thermal Imaging microscope !
AGA is the forefather of Agema who became part of the much respected FLIR thermal camera manufacturing company. Medical and Industrial applications for thermal imaging include the use of thermal microscopy for examination of very small targets. AGA produced the 680 camera system in the early 1980's for medical and industrial use. You may be assured that the cost of the system would have been truly eye watering !
The thermal camera is a scanning mirror based unit that uses motorised mirrors to create a raster image using only a 1 pixel liquid nitrogen cooled thermal sensor. Scanning systems were common and standard in the thermal camera market place in the 1980's. They may sound very Heath Robinson like the early mechanical raster Televisions, but they are in fact precision machines that made thermal imaging possible in an era when even a single pixel sensor cost a small fortune...staring array technology had yet to be made. Liquid Nitrogen is not uncommon in industry and medical institutions so was not considered a great disadvantage. A very different situation for the home user however ! Your average Jo would not have had the finances for such a purchase though.
The 680 is the main camera cylinder that may be fitted with a variety of large aperture lenses and the specialist microscope head. The Liquid Nitrogen is poured into the top rear mounted port that may be seen in the pictures. The Vacuum Dewar contains enough Liquid Nitrogen for a 4 hour operating time before a refill is needed. The 680 camera passes its scanned image data to the control and display unit via a long umbilical cable. Due to size and weight the 680 is normally operated on a tripod or desk mount. The microscope version of the 680 would normally be mounted on the test jig that is used for sample inspection. The microscope head contains both an optical and thermal microscope lens structure. The optical microscope is used to align the sample correctly. The thermal lens is then moved into position on a slide assembly and the thermal images captured. The microscope provided 15X magnification.
The camera also contains a number of specialist thermal imaging filters that may be placed in front of the thermal sensor. these include a 2000C range extender, water imaging filter, sunlight filter and various attenuation filters. These filters are all designed to be user removable and sit in their own individual filter holder modules.
Why did I purchase it ?
1. It has a very rare and useful thermal microscope head that would cost a small fortune to purchase today. Perfect for in depth PCB inspection.
2. I collect thermal cameras of all ages and types
3. I suspected the unit would sell cheaply as there is no controller and it is old.
4. It was located less than 1 mile from my home
The unit sold today for GBP35 and I collected it this afternoon.
I have quickly opened the unit to see what lives inside. as expected the build quality is similar to that found in military equipment. Built like a tank and of very high quality. Cables are neatly laced, the chassis is large and heavy providing rigidity, the optical path is enclosed in machined aluminium modules, the motors are superb quality and the gearboxes use metal precision gears and clutches. Hmmmm nice engineering.
Now this camera will never be returned to service and is just a sample of the technology for my collection. I don't bother playing with Liquid Nitrogen these days.... nasty stuff if handled or stored incorrectly. Now the microscope head.... that is a different matter. It is a LW lens assembly and so may be used with my industrial FLIR thermal cameras. I hope to use it as a thermal camera microscope again for PCB and other work, such as thermal imaging of insects
Time for the pictures......