Experiment No. 2

Specific Gravity Determination

Objective:

The activity aims to determine the specific gravity of fluids using U-tube manometer

Intended Learning Outcomes (ILOs):

The students shall be able to:

1. Determine the specific gravity of fluids using U-tube manometer

2. Expand the knowledge on other uses of U-Tube in other experiments.

Apply the techniques and skills in using U-Tube relevant to professional engineering practice.

Discussion:

Specific gravity of a fluid is the dimensionless ratio of specific weight y or density p of a fluid to the specific

weight ys or density ps of the standard substance,

s= yy s

= pps

For liquids and solids, the standard substance is pure water at 4oC at which temperature, its specific

weight, ys = 9.81KN/m3 and ps = 1000 kg/m3 are at their maximum values. With these constants, equation 1.1 may

be used to compute the specific weight and density of a fluid given its specific gravity s. For gases, the standard

substance is either hydrogen or air at 0oC and under a pressure of 101.3 KPa. Air at this temperature and

pressure has ys = 12.7 N/m3 and ps = 1.29 kg/m3.

The specific gravity should not be confused with the density since these are two different properties of a

substance, the first one being dimensionless and the second having the dimensions kg/m3 or gm/cm3. In the SI

units, however, these two are numerically equal if the density is expressed in gm/cm3. For example, water has

specific gravity of unity and a density of 1 gm/cm3.

Resources/Instruments Required:

U-tube Manometer

Scale

Liquids whose specific gravity are to be determined

Procedure:

1. Pour a quantity of distilled water in the U-tube glass manometer.

2. Add a quantity of soil inside the U-tube glass manometer until it stands

3. Measure the heights of water and oil inside the U-tube.

4. Using the formula derived below. Determine the unknown specific gravity of your desired liquid.

p1

yH 2O+Y 1

h1−

p2

yH 2O

(1.2)

Points 1 and 2 and are exposed to the atmosphere, therefore, gage pressure is zero

S1 yH 2Oh1=S2 yH 2Oh2

(1.3)

If fluid 1 has known specific gravity, then

S2=S1h1

h2

(1.4)

5. Perform steps 1 to 4 with other liquids. For heavy liquids, use mercury as standard fluid.

Data and Results:

FLUID H1 H2 H3

KEROSENE 7 9 5.7

DIESEL 7 7.85 7.3

OIL 7.3 17 9.3

Computation:

H K 1=H−X=15.5−8.5=7

H K 2=H−X=16.7−7.7=9

H K 3=H−X=13.3−7.6=5.7

H D1=H−X=11−4=7

H D2=H−X=15.7−7.85=7.85

H D1=H−X=16.3−9=7.3

HO1=H−X=13−5.7=7.3

HO2=H−X=22.9−5.9=17

HO3=H−X=17−7.7=9.3

Specific Gravities:

S .G .K 1=HW 1

H K 1=8.9

7=1.271

S .G .K 2=HW 2

H K 2=11.5

9=1.278

S .G .K 3=HW 3

HK 3=7.2

5.7=1.263

S .G .D1=HD 1

HD 1=8.1

7=1.157

S .G .D2=HD 2

HD 2=9.15

7.85=1.166

Assessment: (Rubric for Laboratory Performance):

CRITERIA BEGINNER1

ACCEPTABLE2

PROFICIENT3

SCORE

I. Laboratory Skills

Manipulative

Skills

Members do not demonstrate

needed skills.

Members occasionally demonstrate

needed skills.

Members always demonstrate

needed skills.

Experimental

Set-up

Members are unable to set-up the

materials.

Members are able to set-up the

materials with supervision.

Members are able to set-up the

materials with minimum supervision.

Process Skills Members do not demonstrate

targeted process skills.

Members occasionally demonstrate

targeted process skills.

Members always demonstrate

targeted process skills.

Safety

Precautions

Members do not follow safety

precautions.

Members follow safety precautions

most of the time.

Members follow safety precautions

all the time.

II.Work Habits

Time

Management/

Conduct of

Experiment

Members do not finish on time with

incomplete data.

Members finish on time with

incomplete data.

Members finish ahead of time with

complete data and time to revise

data.

Cooperative

and Teamwork

Members do not know their tasks

and have no defined

responsibilities. Group conflicts

have to be settled by the teacher.

Members have defined

responsibilities most of the time.

Group conflicts are cooperatively

managed most of the time.

Members are on tasks and have

defined responsibilities at all times.

Group conflicts are cooperatively

managed at all times.

Neatness and

Orderliness

Messy workplace during and after

the experiment.

Clean and orderly workplace with

occasional mess during and after

the experiment.

Clean and orderly workplace at all

times during and after the

experiment.

Ability to do

independent

work

Members require supervision by the

teacher.

Members require occasional

supervision by the teacher.

Members do not need to be

supervised by the teacher.

Other Comments / Observations:TOTAL SCORE

RATING = (Total Score)

24 x

100%

TECHNOLOGICAL INSTITUTE OF THE PHILIPPINES1338 ARLEGUI STREET, QUIAPO, MANILA

COLLEGE OF ENGINEERINGCIVIL ENGINEERING DEPARTMENT

FLUID MECHANICSCE 402 – CE41FA2

EXPERIMENT NO. 2SPECIFIC GRAVITY DETERMINATION

SUBMITTED BY:STUDENT NUMBER SIGNATURE

LEADER:1411447 Alcayde, Marielle Noedin M.

MEMBERS:1210573 Amoroso, Jonathan D. 1411715 Castro, Edlyn Cloyd C. 1210369 Gutierez, Jerico Noel T. 1411683 Quimson, Jay Christian J. 1420235 Solano, Kim Carlo R.

SUBMITTED TO:ENGR. GERARDO G. JUSTO

INSTRUCTOR

November 25, 2015