Question

A pressure instrument has a span of 0 – 100 inH2O. A measurement results in a value of 50 inH2O for pressure. Calculate the error if the accuracy is (a) +2.0% FS, (b) +1.0% of span, and (c) +0.5% of reading. What is the possible pressure in each case?

Answer 1

a) + 2.0 % F.S.

Error = (2/100) x 100 = + 2 inH2O.

Here 100 is the full scale of instrument.

For reading of 50 inH2O, the possible pressure is 50-52 inH2O

b) + 1.0 % of Span

Error = (1/100) x (100-0) = + 1 inH2O. Here (100-0) is the span of instrument i.e. difference between upper and lower range value.

For reading of 50 inH2O, the possible pressure is 50-51 inH2O.

c) + 0.5% of Reading

Here reading = 50 inH2O

Error = (0.5/100) x 50 = + 0.25 inH2O

The possible pressure is 50-50.25 inH2O

answered by: anonymous