Pressurized

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.

Pressurized

When subjected to sufficient pressure in a closed container, some gases become liquids at normal temperatures. Called liquified gases, common liquified gases include: anhydrous ammonia, chlorine, propane, nitrous oxide and carbon dioxide. Equilibrium inside the tank means that the contents exists in a liquid-vapor balance state. In contrast, some gases, called non-liquified gases, including oxygen, nitrogen, helium and argon, do not become liquid even at very high pressures. However, with lower temperatures as well as higher pressure, some gases, such as oxygen, can be converted to a liquid. The differences in these processes are used for scientific, industrial and commercial purposes. At or above its critical temperature, no amount of pressure will cause the gas to liquefy. The minimum pressure required to liquefy a gas at its critical temperature is called the critical pressure. When pressure is an essential part of the process, both the pressure and the temperature are controlled and monitored.

Carbon dioxide pressure-temperature phase diagram

Carbon dioxide pressure-temperature phase diagram. Source: Wikipedia.

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

Oxygen Tank 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.

Oxygen Tank Pressure

For many reasons, patients that require additional oxygen use storage tanks with compressed oxygen to supplement their normal air intake.  The size and subsequent capacity of the tank may vary but the full pressure is typically about 2,000 psi and can go as high as 3,000 psi. With this pressure level in the tank, a regulator converts the supplied pressure to a lower, and much safer, level for the user. With newer aluminum and other materials instead of steel to avoid magnetism problems in situations such Magnetic resonance Imaging (MRI) tests, the pressure level is lower. Minimum pressure in tanks is around 300 psi with delivery systems operating at pressure below 400 psi. In contrast, the storage and delivery system of liquid oxygen in a hospital, pressures are usually around 50.0–55.1 psi. The amount of oxygen present inside the cylinder is measured by the pressure at the outlet nozzle.

PV/T = constant

where P is pressure in the cylinder,

V is the volume of the cylinder,

and T is the temperature

Applied Home Healthcare Equipment

Image courtesy of Applied Home Healthcare Equipment.

Normal clean air contains 19% to 21% oxygen. In contrast, a supply of 60% oxygen with 40% nitrogen is considered acceptable for most clinical purposes but usually high much higher content is available.

Portable oxygen cylinders often have flow and pressure gauges. They provide easy, on sight measurements for a user. However, remote monitoring can use microelectromechanical systems (MEMS) pressure sensors to provide an electrical signal that can be transmitted to one or more receivers.  With this information displayed remotely, a variety of healthcare givers can access and use the information.

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

Correct Pressures for Medical Procedures

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.

Correct Pressures for Medical Procedures

Gas control, medical control systems, air compressors and vacuum pumps are all possible equipment used in a medical or even a veterinary office. In all of these systems, monitoring and controlling the pressure is necessary to achieve the proper, efficient and safe values.

Patton's Medical gas control panel for nitrogenThe Patton’s Medical gas control panel for nitrogen clearly shows the supply (95 psi) and outlet (82 psi) pressures.

While gages are commonly used so medical personnel can easily observe the pressures during a procedure, microelectromechanical systems (MEMS) sensors could easily be installed behind the panel and then communicate the data to a local or remote monitoring station. With digital data, warnings can be implemented and archived data can be used to show that proper levels of critical elements, such as oxygen, were maintained during an operation.

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

Pressure and Gas Chromatography

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.

Pressure and Gas Chromatography

Gas chromatography uses stationary and mobile phases for separating and analyzing mixtures according to “Chromatography Composition Measurement,” in The Measurement, Instrumentation, and Sensors Handbook. To perform the necessary steps, the typical gas chromatograph has several different aspects. It starts with a pressure regulated carrier gas supply. The carrier gas pressures are typically 34 to 69 kPa (5 to 10 psig) to 138 to 340 kPa (20 to 50 psig) at gas flow rates of 1 mL min-1 or less. If the data system monitors and records the supplied pressures, pressure sensors would also be used.

To measure this range of pressures, All Sensors SPM 401 Series of media isolated sensors would provide a good solution since process control and monitoring systems are target applications.

Gas Chromatograph

The components of a gas chromatograph include regulating gas pressure.  Source: http://faculty.uml.edu/david_ryan/84.314/Instrumental%20Lecture%2016.pdf

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