The Need for Temperature measurement
Though Temperature measurement is one the slowest process variable to be measured but stands to be one of the most important variable to be measured.
In the medical field precise temperature measurement is essential for proper administering of drugs, the manufacturing industries can not do without temperature measurement, In the food confectionary the temperature of an oven must be kept constant or you have partially or over baked bread.
In the oil and gas industry, Temperature measurement is essential for the safety of Man and the asset. The temperature of a crude oil export pump must not exceed certain threshold or else the only element (heat or ignition source) insufficient for fire to occur will become sufficiently abundant for the completion of the fire triangle.
Some of our products like the wet produced gas may need some form of heat to get dry, The heat to be applied must be regulated and measured in form of temperature or else there will be an explosive mixture.. What about our boilers? So, quality and safe production requires adequate knowledge of temperature measurement.
Some of the Principles use for Temp. Measurement
1. The Bimetalic Strip.
In our elementary knowledge of physics, we have an understanding of how metals expand and increase in length as their temperature rises, however, the rate of expansion per degree rise in temperature (coefficient of Linear expansivity) differs from metal to metal.
Now, when two metals of different coefficient of Expansivity are bonded together side by side as in the diagram below, a change in temperature will cause both
Metals to expand, but because of the difference in there expansion rate, the bonded metal begins to bend in a particular direction as shown in the diagram, and when the heat source is taking away the bonded metals straightens up again. This movement due to the applied heat can be linked to a graduated temperature scale to be read directly as the temperature. It can also be used as a temperature switch i.e opening and closing a contact.
There are several other principles involve in temperature measurement but we shall discuss and do a practical demonstrate in our upcoming training. Click the link to register http://Www.pbplusoilandgas.com/courses
see you soon!
GEORGE EUGENE BASARA
Process Authomation, Control and Optimisation.