## Pressure in the Panama Canal and Other Locations

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities and you. In this blog we’ll be discussing pressure sensors used in canals.

### Pressure in the Panama Canal and Other Locations

Depending on the direction, the lock system at the Panama Canal lifts or lowers a ship 85 feet to make the transition from the Pacific to the Atlantic Ocean. The pressure can be calculated from Pascal’s Law-

P= ρgh

Where,

P = pressure (Pa = N/m2)

ρ = density of fluid (Water = 1000 kg/m3)

g = gravity (9.81 m/s2)

h = depth (m)

While the Panama Canal is among the most famous canals in the world, several lock systems exist in the continental U.S. including on the Mississippi River, Saint Lawrence Seaway, the Soo Locks at Sault Ste. Marie, Michigan and others. In addition, dams also control the flow of water along many rivers.

At the Panama Canal, 265 meteorological and 52 hydrometric stations were installed  to measure meteorological parameters of pressure, temperature, extreme temperature, humidity, precipitation (quantity and intensity), wind (speed and direction), evaporation, soil temperature, insolation and solar radiation. With the pressure measurements, the hydrometric stations monitor the rivers and lakes levels continuously. Modern pressure sensors allow even more measurements to be made and communicated to remote monitoring locations for a variety of purposes.

The dam on Miraflores Lake at the Panama Canal.

Do you have a pressure sensing question? Let me know and I’ll address it in an upcoming blog.
-Han Mai, Senior Marketing Specialist, All Sensors Corporation ([email protected])

## What does a psi matter anyway?

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities and you. In this blog we’ll look at why a PSI or two matters.

### What does a psi matter anyway?

Underinflated footballs created a viral controversy before Super Bowl 2015.  Measurements of air pressure of 10.5 pounds per square inch (psi) instead of the minimum 12.5 were the issue. Rather than just talk about the issue (a.k.a. Deflategate), engineers performed calculations and more. One company conducted experiments as well.

In its testing, HeadSmart Labs found that on average, footballs dropped 1.07 psi from temperature change in a 75°F room to a 50°F room. Exposing the football to water resulted in an additional 0.75 psi pressure drop. With the combined effects, the footballs’ pressure decreased by an average of 1.82 psi to a max of 1.95 psi.

Richard P. Binzel, professor of planetary science at MIT, calculated that a 5 to 10% drop in temperature could create a drop of 0.5 to 1.5 psi, in a football’s air pressure. Equally important, he noted that the accuracy of the meters used to measure the footballs is unknown.

The bottom line for this or any critical pressure measurement is that for accurate measurements, especially at lower pressures, temperature changes are among the operating environment aspects that should be taken into account and accurate meters need to be used.