Question

an open end manometer is filled with mercury so that each side has a height equal to 26.3 cm. If the atmospheric pressure is 757 torr on a given day what are the approximate max and min pressures that this manometer can measure? Find the minimum and maximum pressures

Answer 1

The open-end manometer can measure a minimum pressure of approximately 231 torr and a maximum pressure of approximately 1283 torr, based on a given atmospheric pressure of 757 torr.

Step-by-step explanation:

To calculate the minimum and maximum pressures that the open-end manometer can measure, we need to consider the maximum and minimum heights the mercury can reach in the manometer tube.

Since each side of the manometer is initially at 26.3 cm (263 mm) with an atmospheric pressure of 757 torr, the minimum pressure it can measure is when the gas pressure is zero and all the mercury is on one side. In this case, the maximum height difference would be

2 x 263 mm = 526 mm.

Since 1 torr is essentially one millimeter of mercury, the minimum pressure the manometer can measure is around 757 torr - 526 mm = 231 torr.

Conversely, the maximum pressure occurs when the mercury is entirely on the atmospheric side, giving us a pressure reading of

757 torr + 526 mm = 1283 torr.