Match the following, instrument with its purpose:

Instrument	Purpose
1. Manometer	a. To measure the pressure at a point in a fluid
2. Nozzle meter	b. To measure velocity of flow of fluid
3. Pitot tube	c. To measure the rate of flow of fluid
4. Hydrometer	d. To measure the density of certain fluid

Explanation:

Manometer:

• Purpose: Measures the pressure at a point in a fluid using the height difference in a column of liquid (usually mercury or water).

• Types: Common types include U-tube, inclined, and differential manometers for measuring gauge and differential pressures.

• Working Principle: Based on hydrostatic pressure, i.e., the pressure exerted by a static fluid column.

• Applications: Used in laboratories, pipelines, gas systems, and HVAC systems to measure static pressures accurately.

 Additional InformationNozzle Meter

• Purpose: Used to measure the rate of flow (discharge) of fluid in a pipe using the Bernoulli principle and continuity equation.

• Construction: Consists of a converging nozzle installed in a pipeline and pressure taps at upstream and throat sections.

• Operation: Flow rate is calculated from the pressure difference between the two sections using a discharge coefficient.

• Comparison: Similar to venturimeter and orifice meter but is more compact and causes less pressure loss than an orifice meter.

Pitot Tube

• Purpose: Designed to measure the velocity of fluid flow, especially in open channels, ducts, or air streams.

• Working Principle: Measures the difference between static and stagnation pressure to determine velocity using Bernoulli’s equation.

• Structure: Consists of a tube pointing into the flow to capture stagnation pressure and holes on the side for static pressure.

• Applications: Widely used in aerodynamics, hydraulics, HVAC systems, and aircraft for airspeed measurement.

Hydrometer

• Purpose: Measures the specific gravity or density of a liquid by floating at a certain level based on buoyant force.

• Working Principle: Based on Archimedes’ principle, which states that a body immersed in fluid is buoyed up by a force equal to the weight of the displaced fluid.

• Scale Readings: The scale on the stem gives direct reading of specific gravity, which can relate to concentration or purity.

• Applications: Commonly used in battery maintenance, breweries, petroleum industry, and chemical labs to assess fluid quality.