How To Read A Min / Max Thermometer

LOL was bored the other day and wanted something to do, so I wondered what the temperature was in our loft during this cold snap, I found a new but unused min / max thermometer in the garden shed.

It's just a non digital Min / Max thermometer type filled with mercury and a U Tube plus a reset button and two floats for the min / max temperature - my question is when taking a reading should this be done from the bottom of the float or the top of the float?

It just make a big difference on the scale as the top of the float reads -1C whilst the bottom of the float reads 3.C

I would think that you read from the bottom of the float (3.C) but just wanted to be sure?

 

Good Question.

 

If you take the reading from the top of the mercury and the float sits on top of the mercury, then it would be the bottom of the float

 

Top of mecury/bottom of 'float' as above post. Looking at the posted image the temp was 20 deg C when it was taken which was top of mercury on the MIN left hand column and bottom of float on the MAX right hand column.

From http://en.wikipedia.org/wiki/Six's_thermometer (they were invented by J.W. Six)

P.S. Watch out for air bubbles below the pins if you drop or knock it over.