Benjamin S. Valle
The question asks how many pounds per square inch does
the box exert. Put 62.4 pounds in the numerator and 144
square inches in the denominator, divide, and you get 0.433 psi
Multiply it by 20, we get the psi of the 20-foot-high column
Now we multiply that by 1.5 because the substance in this
problem has 1.5 times the mass of water (0.433 x 20 x 1.5 = 12.99)
glass tube partially filled with liquid.
This manometer has no moving parts and requires no calibration.
Manometer measurements are functions of gravity and the liquid’s density, both physical properties that make the U-tube manometer a NIST standard for accuracy.
The liquid moves until the unit weight of the liquid, as indicated by h, exactly balances the pressure.
The principle of a deadweight tester is very simple. A deadweight tester consists of a piston/cylinder combination and a set of weights. The area of the piston and the mass of the weights have been accurately determined. The calibration fluid 5 is pressurized by means of a ram screw 6 to the point where the piston 1, including the weights 3, starts to float, whereby the forces are balanced. Since From Newton’s law force (F) is equal to mass (m) times acceleration (g). Pressure (P) is equal to force divided by area (A). Example: The area of the piston is one square inch, the set of weights is 10 pounds, therefore the pressure generated is
P = F = 10 lbs = 10 psi
A = 1"
The pressure gauge should also read 10 pounds per square inch.
Advantages of using a deadweight tester:
Simple operation. Disadvantages of using a deadweight tester:
Not a portable device
Suitable for use in laboratory only
Time consumingstyle="margin-top: 0pt; margin-bottom: 0pt; direction: ltr; unicode-bidi: embed; vertical-align: baseline;">Generated pressure cannot be read from a display but has to be calculated from the applied weights
Corrections for gravity and temperature are requiredemail: firstname.lastname@example.org