I believe there have been a large number of typographical issues regarding the temperature values as presented in this article.
For example the K type thermocouple is described as having a range of 200-23000F or 96-12600C, where this should actually read 200-1300F or 96 – 1260C, the 'degree' symbols have been somehow become transcribed as an additional 0 throughout much of the article.
There is also an inconsistency with reporting the numbers, sometimes 400C and sometimes with a gap between the number and the C, such as 400 C, again adding to the confusion regarding the actual temperature being discussed, which in reality was only 40C.
I also appreciate that such items are not easy to pick up on any proof reading, as these are all still valid temperature values, however, in a technical article such as this one where most of the article is about precise temperature control, the values as shown are wildly misleading .