1. The problem statement, all variables and given/known data A closed-end manometer is used to measure the pressure of a sample of a given gas. The level of mercury (Hg) is 18 mm higher in the part of the tube connected to the sample than in the other part. Determine the gas pressure in kilo-pascals, if the atmospheric pressure is 99.7 kPa. 2. Relevant equations For a closed-end manometer, it is my understanding, and perhaps I am wrong, that the atmospheric pressure does not matter. Rather, you would only measure the difference in height (closed - sample) and that would be the pressure in mmHg. So, I don't understand how the sample side could be 18 mm higher.