Answer:
It will decrease
Explanation:
We have to remember that the atmospheric pressure it the amount of air that is putting pressure on an object, when it is at sea level, atmospheric pressure is 1 since there is one-atmosphere putting pressure on the object, as we increase the altitude of the object atmospheric pressure steadily decreases, so bringing any kind of manometer up a mountain would make the reading to decrease since there is less atmospheric pressure acting on the object.
