Sight glasses are an invaluable tool for troubleshooting towers and checking instruments. However, they can lead the unwary down trails to false conclusions. Make sure you understand the system. Then apply the fundamentals of how sight glasses work as DP instruments rather than jumping to the conclusion that they must always show the liquid level inside the tower.
Correct field technique minimizes the probability of getting
poor data. Inaccurate data is worse than no data. No data forces
you to make a judgement or to look for alternate methods. Inaccurate
data leads to the wrong conclusion: ineffective decisions: and
wastes money and time.
Electronic version available in Adobe Acrobat PDF format file 092.PDF 50k.
Request paper 092.