Question

For measuring the differential pressure using U tube mamometer which of the following statement is INCORRECT regarding the desirable property of the manometric fluid

• A. fluid should have low viscosity
• B. fluid should have high co-efficient of thermal expansion
• C. fluid should have low vapour pressure
• D. Fluid should be Non-corrosive and have Non-sticky effects

Answer 1

The correct option is B fluid should have high co-efficient of thermal expansion

since the value of measured pressure is affected by change in density of manometric fluid which is dependent upon temperature. Therefore, in order to maintain constancy of calibration, the density of manometric fluid should not change with temperature and hence fluids with low co-efficient of thermal expansion should be used.