(a) Fluid depth must be the same on both sides, or the pressure each side exerts at the bottom will be unequal and there will be flow from the deeper side. Assume that the IV bag is collapsible.For the fluid to just enter the vein, its pressure at entry must exceed the blood pressure in the vein (18 mm Hg above atmospheric pressure). The person making the measurement then slowly lowers the applied pressure and listens for blood flow to resume. There is no mystery here. Here’s an example:A maintenance team wishes to measure the NPSHa of a pump located in a facility that is 1,500 feet above sea level. If you limp into a gas station with a nearly flat tire, you will notice the tire gauge on the airline reads nearly zero when you begin to fill it. Assuming that the density of the fluid being administered is 1.00 g/ml, at what height should the IV bag be placed above the entry point so that the fluid just enters the vein if the blood pressure in the vein is 18 mm Hg above atmospheric pressure? Absolute Pressure = Gauge Pressure + Atmospheric Pressure P abs = P rel + P atm Absolute pressure is used mainly to measure pressures for aircraft’s, etc. Pumps and their associated systems are designed to produce and retain pressure. Air pressure inside the submarine is 1.00 atm.7. [latex]\begin{array}{}\Delta P=\text{38.7 mm Hg,}\\ \text{Leg blood pressure}=\frac{\text{159}}{\text{119}}\end{array}\\[/latex]Gauge pressure is the pressure relative to atmospheric pressure. You may have noticed that the bags used for blood collection are placed below the donor to allow blood to flow easily from the arm to the bag, which is the opposite direction of flow than required in the example presented here.Figure 4. After the next mouse click on any free space of the window or the "calculate" … Assume that there is no loss of pressure due to resistance in the circulatory system (a reasonable assumption, since major arteries are large).6. Absolute pressure versus gauge pressure The absolute pressure of any system is the gauge pressure of the system plus the local atmospheric or ambient pressure. In fact, if there were a gaping hole in your tire, the gauge would read zero, even though atmospheric pressure exists in the tire. What is the effect of raising the arm above the shoulder? PSI Gauge is the pressure from gauge, it equals PSI Absolute + 1 atmosphere pressure. The bicycle plus rider has a mass of 80.0 kg, and the gauge pressure in the tires is 3.50 × 105. The pressure due to the mercury’s weight, 1. This happens because of Pascal’s principle. In routine blood pressure measurements, an inflatable cuff is placed on the upper arm at the same level as the heart. Considering the magnitude of typical arterial blood pressures, why are mercury rather than water manometers used for these measurements?1. Blood flow is detected just below the cuff, and corresponding pressures are transmitted to a mercury-filled manometer. We therefore need to find the height of fluid that corresponds to this gauge pressure.We first need to convert the pressure into SI units. }0\times {\text{10}}^{3}{\text{kg/m}}^{3}\right)\left(9\text{. At that elevation, the atmospheric pressure is 13.91 PSIA. (credit: U.S. Army photo by Spc. The system’s instruments indicate a suction pressure of 74 PSIG and a liquid vapor pressure of 72 PSIA. Assuming bicycle tires are perfectly flexible and support the weight of bicycle and rider by pressure alone, calculate the total area of the tires in contact with the ground. Figure 3 shows how a common measurement of arterial blood pressure is made. In all mechanical pressure gauges, pressure results in a force that is converted (or transduced) into some type of readout.Figure 1. It is determined by subtracting the liquid vapor pressure from the suction pressure:It sometimes happens that the component pressures of the NPSHa calculation are measured in different units. Calculate the pressure you would observe (in units of mm Hg) if the pressure at the heart were 120 over 80 mm Hg. An open-tube manometer has one side open to the atmosphere. In the United States, pressure is often described as pounds per square inch, or PSI.