Tag Archives: safety

Fire Extinguisher Pressure

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.

Fire Extinguisher Pressure

Caution: Contents under pressure. The typical residential or consumer fire extinguisher comes with this warning and a pressure gauge to ensure that it is in a safe zone and prepared for use should the occasion arise.

An extinguisher designed for use with a dry chemical only (ABC powder) like the one on the left in the figure is pressurized to 195 psi (1,344 kPa). Its gauge is in the green zone indicating that it is ready use. The clockwise red zone indicates an overcharged situation that could measure as much as 400 psi (2,758 kPa). A counterclockwise measurement below the safe zone, like the one on the right, means the extinguisher has lost charge and needs to be recharged to be effective. With only three pressure readings available (0, 195 and 400 psi), significant interpolation is required to determine the pressure if the reading is outside of the set range. Since the operating pressure is 195 psi and the pressure could go as high as 400 psi, tanks are pressure tested at an even higher level such as 585 psi (4,033 kPa) to ensure that they are safe. For this testing and other measurments in the manufacturing process, an accurate electronic measurement with high resolution, like the All Sensors CPM 602 Series, could provide the answer.

Fire Extinguisher

Comments/Questions?
Do you have a pressure sensing question? Let us know and we’ll address it in an upcoming blog.
Email us at info@allsensors.com

Jumping for Joy Over Pressure

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 discuss air pressure and safety in bounce houses.

Jumping for Joy Over Pressure

When the weather is nice and a special event warrants a bounce house, kids get a first-hand experience of the importance of pressure. The air-filled chambers allow bouncing, falling and a lot of fun. Maintaining the pressure requires a pump to run continuously and usually the required pressure is not measured or displayed because it has been predetermined in pre-production design and testing. Unlike a thick rubber tire, the relatively thin vinyl material of the bounce house only requires a few psi to elevate it above the hard ground. With names like Cloud 9 and Jump for Joy as suppliers, it is easy to see how the inflated structure takes children away from the normal day-to-day realities. However, safety is still an issue.

post29v2

When safety in a bounce house is discussed, it usually involves parts per million (ppm) of potentially toxic materials  including lead or human contamination. According to one source’s analysis of a specific product, “Lead levels in the vinyl, the tests found, varied from 5,000 parts per million to 29,000, far above the federal limit of 90 to 300 parts per million.” Fortunately, pressure problems are not a concern, since under or over inflation are easily observed by both visual and audible (the pump’s noise) human sensing.

What do you think/Comments?
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 (hmai@allsensors.com)

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.

footballPNG

What do you think/Comments?
Do you have a pressure sensing question? Let me know and I’ll address it in an upcoming blog.
-Dan DeFalco, Marketing Manager, All Sensors Corporation (ddefalco@allsensors.com)

Tire Pressure: Not all Measurements are the Same

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 tire pressure measurements.

Tire Pressure: Not all Measurements are the Same

The proper tire pressure in passenger cars and trucks provides optimum safety and efficiency.  Since drivers did not check tire pressures as frequently as they needed to, the U.S. Department of Transportation’s (DOT’s) National Highway Traffic Safety Administration (NHTSA) Transportation Recall Enhancement, Accountability, and Documentation (TREAD) Act of 2000 requires a tire pressure monitoring system (TPMS) on every new vehicle (all passenger cars and light trucks under 10,000 lbs. Gross Vehicle Weight) sold in the U.S. after November 2006.

Not all tire pressure measurements are the same. Car tire pressures are typically 30 to 35 psi with truck values running slightly higher. If you have an ATV, the tire pressure could be more like 8 psi max with some being as low as 2.7 psi and some as high as 10 psi. If you ride a road bicycle, the pressure can range considerably and depends on your weight with tire pressures of 95-105 psi for 110# riders to 125-135 psi for a 230# rider suggested from one source.

You can find tire pressure measurements in some unusual places. The Shipwreck water slide at SeaWorld uses large tires to carry several riders. The tire bumps into the sides of the slide to provide added excitement to the ride. For safety purposes, a maximum rating of 2.9 psi or 0.2 bar is recommended.

Shipwreck water slide uses large tires

The variety of tire pressure readings means that a single pressure sensor cannot provide the required accuracy and precision for all applications.

What do you think/Comments?
Do you have a pressure sensing question? Let me know and I’ll address it in an upcoming blog.
-Dan DeFalco, Marketing Manager, All Sensors Corporation (ddefalco@allsensors.com)