I walked into the Doctor’s surgery the other day, and instead of the familiar
mercury in glass blood pressure measuring instrument there was a brand new
Well, of course you might assume that this would be more accurate than the old
mercury in glass type, but you would be wrong. Mercury in glass is the gold
standard. The Bourdon tube gauge is not very accurate for low pressure and is
subject to errors as the tube inside looses its ability to return to the zero
Bourdon tube gauges need expensive checking and adjustment by skilled
technicians every few years. They are not more robust than the glass type, are
subject to hysteresis (you get a different reading when the pressure is rising
from the reading obtained when the pressure is falling), and are sensitive
to shocks and vibrations.
Mercury in glass is superior in every respect for this kind of measurement.
Why change? Super nanny EU has discovered that mercury is toxic.
Clinicians have used dangerous mercury for a little over a hundred years. How
many deaths and poisonings? I can not find a record of a single one.