Question

A bourdon tube, which has a range of 0 to 50 bar, reads +0.5 bar when measuring atmospheric pressure. It is claimed to have an accuracy of ±0.2% of full scale reading. For an applied pressure of 30 bar, the reading would be expected to be in the range of

(a) 31.5 bar – 31.8 bar
(b) 30.4 bar – 30.6 bar
(c) 30.5 bar – 30.8 bar
(d) 29.4 bar– 29.6 bar

Answer 1

option c is the answer...

Answer 2

Given :

Range of tube = 0- 50 bar

Reading of tube = + 0.5 bar

Accuracy of scale = ± 0.2%

Applied pressure = 30 bar

To find :

Reading range

Solution:

As it is given that the range of scale is 0 to 50 bar.

So it can have readings from 0 bar to 50 bar,

which has 0.5 bar as minimum reading that can be read.

Accuracy of is ± 0.2 % of full scale =

$\frac{0.2}{100} \times \: 50$

= ± 0.1 bar

So, The accurate reading range can be ± 0.1 bar from the total reading.

As, it is given that

Main scale reading is 30 bar

With +0.5 bar

and accuracy of ± 0.1 bar

So,

Range of reading = 30 + 0.5 ± 0.1 bar

= 30.5 ± 0.1 bar

So the range of reading = 30.5 - 0.1 bar to 30.5 + 0.1 bar

So the range of reading = 30.4 - 30.6 bar

So, Option B is correct