The image above represents standard permeability of sand.

To compute for standard permeability of sand, five essential parameters are needed and these parameters are **Volume of Area (V), Height of Sand Specimen (H), Pressure (P _{r}), Cross-Sectional Area of Sand Specimen (A) **and

**Time (t).**

The formula for calculating the standard permeability of sand:

P = ^{VH} / _{PrAt}

Where:

P = Standard Permeability of Sand

V = Volume of Air

H = Height of Sand Specimen

P_{r} = Pressure

A = Cross-Sectional Area of Sand Specimen

t = Time

Let’s solve an example;

Find the standard permeability of sand when the volume of air is 6, the height of sand specimen is 3, the pressure is 8, the cross-sectional area of sand specimen is 5 and the time is 2.

This implies that;

V = Volume of Air = 6

H = Height of Sand Specimen = 3

P_{r} = Pressure = 8

A = Cross-Sectional Area of Sand Specimen = 5

t = Time = 2

P = ^{VH} / _{PrAt}

P = ^{6 x 3} / _{8 x 5 x 2}

P = ^{18} / _{80}

P = 0.225

Therefore, the **standard permeability of sand **is **0.225.**

**Calculating the Volume of Air when the Standard Permeability of Sand, the Height of Sand Specimen, the Pressure, the Cross-Sectional Area of Sand Specimen and the Time is Given.**

V = ^{P x PrAt} / _{H}

Where:

V = Volume of Air

P = Standard Permeability of Sand

H = Height of Sand Specimen

P_{r} = Pressure

A = Cross-Sectional Area of Sand Specimen

t = Time

Let’s solve an example;

Find the volume of air when the standard permeability of sand is 10, the height of sand specimen is 2, the pressure is 4, the cross-sectional area of sand specimen is 8 and the time is 1.

This implies that;

P = Standard Permeability of Sand = 10

H = Height of Sand Specimen = 2

P_{r} = Pressure = 4

A = Cross-Sectional Area of Sand Specimen = 8

t = Time = 1

V = ^{P x PrAt} / _{H}

V = ^{10 x (4)(8)(1)} / _{2}

V = ^{320} / _{2}

V = 160

Therefore, the **volume of air **is **160.**