Equipment
1.) Permeameter with its accessories: The permeameter is made of noncorrodible material with a capacity of 1000 ml, with an internal diameter of 100±0.1 mm and effective height of 127.3± 0.1 mm.
2.) Standard soil specimen, 3.) Deaired water, 4.) Balance to weigh up to 1 gm,
5.) I.S sieves 4.75 mm and 2 mm, 6.) Mixing pan, 7.) Stop watch, 8.) Measuring jar,
9.) Meter scale, 10.) Thermometer, 11.) Container for water, 12.) Trimming knife etc.
Experimental Procedure
1. Prepare the soil specimen as specified.
2. Saturate the specimen preferably by using Deaired water.
3. Assemble the permeameter in the bottom tank and fill the tank with water.
4. Inlet nozzle of the mould is connected to the stand pipe. Allow the water to flow until steady flow is obtained.
5. Note down the time interval ‘t’ for a fall of head in the stand pipe ‘h’.
6. Repeat step 5 three times to determine ‘t’ for the same head.
7. Find ‘a’ by collecting ‘q’ for the stand pipe. weigh it correct to 1 gm and find ‘a’ from q/h=a.
Observation and Recording:
Sample No. ………………… Moulding water content: ………………..
Dry Density: ………………. Specific Gravity: ………………………..
Void ratio ………………….



1^{st} set 
2^{nd} set 
3^{rd} set 
1. 
Area of stand pipe (dia. 5 cm) 
a (cm) 



2. 
Cross sectional area of soil specimen 
A (cm^{2}) 



3. 
Length of soil specimen 
L (cm) 



4. 
Initial reading of stand pipe 
h_{1} (cm) 



5. 
Final reading of stand pipe 
h_{2} (cm) 



6. 
Time 
t (sec) 



7. 
Test temperature 
T (^{o}C) 



8. 
Coefficient of permeability at …….. ^{o}C k = 2.303.a.L.(log_{10} h_{1}/h_{2}) / (A.t) 
k (cm/sec) 



9. 
Average Permeability, k_{t} 
k_{t} (cm/sec) 


10. 
_{
}Coefficient of permeability at
27^{o} C : 
k_{27} (cm/sec) 

General Remarks:
1. During test there should be no volume change in the soil, there should be no compressible air present in the voids of soil i.e. soil should be completely saturated. The flow should be laminar and in a steady state condition.
2. Coefficient of permeability is used to assess drainage characteristics of soil, to predict rate of settlement founded on soil bed.
3. Magnitudes of permeability:
High permeability: k > 10^{1} cm/sec
Medium permeability: k » 10^{1} cm/sec
Low permeability: k < 10^{1} cm/sec