I was looking for an Infra Red thermometer to measure the heat on my solar PV panels and for checking my 3D printer. These sensors sense electromagnetic waves in the 700 nm to 14,000 nm range. Whilst tempted by thermal imaging cameras, I was somewhat put off by the £2000-3800 price tag. So, I opted for the cheaper gun like tools. However, there are some DIY options that I will briefly look at first.