Engineering Answers

Question 2

A load cell calibrated at a temperature of 200𝐶 has the following output/input characteristic.

Load in kN 0 0.4 0.8 0.12 0.16 0.20

Deflection of meter in mm 0 10 20 30 40 50

When it is used in an environment of 400

its characteristics change to the following;Load in kN 0 0.4 0.8 0.12 0.16 0.20

Deflection of meter in mm 3 14 25 36 47 58

(a) Determine;

(i) Zero drift

(ii) Sensitivity drift, and

(iii) Sensitivity drift per 0C change in ambient temperature

(b) If 0.5 mm of scale division can be read with a fair degree of certainty, hence

determine the resolution of the instrument in both cases i.e. at 200𝐶 and 200𝐶.

Question 1

The central deflection of the diaphragm of an elastic type pressure measuring instrument was

found to be 0.25mm of an applied pressure of 106𝑝𝑎. The output displacement of diaphragm

has been fed to a Linear variable differential transducer (LVDT) with a built in amplifier

having a sensitivity of 40V/mm. Finally the output is displayed on an analog voltmeter which

has a radius of scale line as 60mm and has a voltage range from zero to 10 volts in an arc of

1500

. Using a well labelled diagram, determine the sensitivity of the given diaphragm gauge

in terms of mm/bar (1 bar=105𝑝𝑎).

Calculatetheareaunderthecurve𝑦=7−𝑥 ,fromx=-1tox=2.

Calculatetheareaunderthecurve𝑦=7−𝑥 ,fromx=-1tox=2.

Simplify the following functions.

(a) (x + y)(x + y’)

(b) xy’+ y