Buying a second-hand thermal camera

[robdejonge]

The FLIR DM284 thermal imager has been offered to me for $450. The current model (285) is about double that, new. It seems a bit of an oddball device, combining a thermal imager with a pretty mediocre multimeter. I’m really just interested in the thermal imaging capability.

https://flir.netx.net/file/asset/9082/original/attachmentP

Ignore the price. It seems a tad on the high side. I’m just curious how I’d evaluate the state of such a device if i were to meet the seller. Of course I can point it at some stuff and see how it reads and if that seems gut-feel-correct … but what are some of the things that break in a device like this and how do I confirm it still works?