Water columns are most commonly used to measure?

Water columns are primarily used to measure low pressure due to their ability to provide a clear and straightforward means of quantifying pressure changes in a fluid. The principle behind using a water column for measurement is based on the relationship between the height of the water column and pressure, where the height directly correlates to the weight of the water above it.

When dealing with low pressures, a water column sensor can effectively gauge the pressure by observing the height of the water it supports. This is particularly useful in applications where low pressure needs to be monitored, such as in HVAC systems or vent systems within buildings. Unlike other mediums, water is readily available, easy to handle, and provides a visible indication of pressure variations.

In contrast, high pressures are usually measured with different types of instruments that can handle the increased force without risk of breakage or overflow, making water columns less suitable for those scenarios. Similarly, while water can be affected by temperature changes, it is not directly utilized for temperature measurement; instead, thermometers and other specific instruments are employed for that purpose. Vacuum measurements, which refer to pressures lower than atmospheric pressure, typically require different methods, such as vacuum gauges, as they operate on different principles than water columns designed for low pressure readings.