HVAC NCCER 03102 Trade Mathematics

What is measurement?

Comparison of a quantity to some definite standard measure of a dimension called a unit

What is area?

The measurement of the surface of a two-dimensional object

Why must a unit of measurement be made apparent?

Due to the variety of different units

Length refers to?

The long side of an object or surface

With Liquid, the measuremenr of the level of fluid in a tank equals?

A measurement of length from the surface of the fluid to the bottom of the tank

How do you determine area of a duct?

Length X Width measured in Square feet.

What is volume?

The amount of space occupied by a three-dimensional object

With Liquid volume why is wet volume calculated?

Due to the liquid measurements used

What is weight?

The force an object exherts on the surface of earth due to mass and pull of gravity

One Kilogram equals?

2.20 pounds

Why are temperature and pressure interdependent?

One affects the other in proportion

Pressure inside of refrigerant tanks depends on?

The type of refrigerant and ambient temperature surrounding the drum

Pounds per square inch equals?

Newtons per square meter (N/m^2)

One Newton per square meter equals?

One Pascal

One bar equals?

14.5 PSI or 100 Kilopascals

A millibar equals?

0.001 Bar

Atmospheric pressure is measured at?

14.7 PSI with 70 degree air at sea level

14.7 PSI equals

29.92 inches of mercury(inHg)

atmospheric pressure also known as

Barometric pressure

Atmospheric pressure is ignored in hydraulic systems but not with?

Low pressures such a fans and blowers

Most gauges measure the difference between?

Atmospheric pressure and pressure within the system

Total pressure in a system is the?

Absolute pressure(PSIa)

PSIa equals?

Atmospheric pressure plus gauge pressure (PSIg + 14.7

Municipal water systems define pressure in terms of?

Static head or height in feet from the point of use to elevated water reservoirs