1) Bourdon Tube
Bourdon tube is a flattened metal tube has an oval cross-section with one end of the
tube connected to the process pressure. The other end is sealed and connected to the
pointer or transmitter mechanism. When a pressure difference exists between the inside
and outside, the tube tends to straighten out and the end moves.
C-type bourdon
o Range as low as 0 - 15 psi up to 0-1500
, g
psi.
o They are simple and accurate, but they are
bulky and get damaged with over-ranging.
Helical bourdon
o Range as low as 0 - 200 psi up to 0 - 6000
psi.
o Heavy-duty helical bourdons can
sometimes tolerate as high as ten times
the maximum range pressure.
Spiral bourdon
o 0 10 psi 0 100 000
7
Range as low as -up to 0-100,000
psi.