Question

Air will demonstrate compressibility effect due to variation in pressure as it travels deep into and out of the mine. Assuming 5% as a mathematically significant effect, at what elevation above or below atmospheric datum will produce a measurable difference in air quantity and pressure loss?

Answer 1

We know difference of pressure between any two points separated by a distance h consisting of medium of density in between them is given by

     ….. (1)

Where denotes difference in pressure between the two points and g is the acceleration due to gravity.

We consider local atmospheric pressure(datum) to be

A change of 5% is detectable

i.e., is detectable

using ,density of airand using equation (1)

Hence, at an height of about 0.5km will produce appreciable change in pressure.