[bidge]

I have a thermometer that i use in diesel analysis. Its lower part is covered with soot and i am not sure if this is not affecting temperature readings. Any ideas how can i clean it? (or should i buy a new one?)

[Borek]

It can slow down the response, but should not change the final reading.

[Hunter2]

Question is it a electronically one using a PT 100 probe or similar or a glas one with a mercury or alcohol filling.
The glas one can be cleaned from the soot using isopropyl pottasium hydroxide mixture, or hot Permanganat with conc. sulfuric acid.
For the PT 100 probably maybe exchange the probe, if the probe also sealed in glas the above solution also can be used.