Sampling

Surveying is tough but as Calvin dad always said, it built character

learn the very basic of weight measurement (ullaging) and samppling

What at difference between University Text and Real World

1) Sampling

a) University - representative sample - what does it means

b) AOCS method (American Oil Chemists' Society)

Draw bottom sample at ascertain sludge; there after inch by inch until sample is free from sludge, then foot by foot until the top
Composite these 60-100 samples into one composite


well for a 60ft tank, we have enough samples to fill a small truck and may take a whole. India (STC) and Pakistani (GCP/TCP) insisted on it and all surveyors certify with their eyes closed that "that the sampling is done accordance to AOCS official methods". This method is drafted about 100yrs ago and nobody bother to dispute it; simply nobody followed it

3) Practical approach

Porim (old MPOB) formulate 3-level sampling - Top/Middle/Bottom
Top - 1 foot from Top, Bottom - 1 foot from Bottom, Middle - middle of Top & Bottom

the above work well with Refined product

As for Crude, practical approach is do not empty out the tank and extend 3 level sampling to 5-level - middle of Top and Middle of Bottom - think it is good enough

If u do have to sweep, prepare to receive sludge (as common to seedoil from South Ameirca) and losses

You always lost oil when emptying out the tank. Why?..... to continue