1.0 ABSTRACT
This experiment is to observe the relationship between the pressure and temperature of a
saturated steam in equilibrium with water and also to demonstrate the vapour pressure curve.
This experiment is carried out by using Marcet Boiler. Marcet Boiler is use for the
understanding of basic properties of saturated steam. Set the temperature controller and
observe the steam temperature rise as the water boils. The steam temperature and different
readings is record as the boiler is heated or cooled. As the result, the temperature increases as
the pressure increase. Some of the values are not the same at the certain point. This is because
some of the errors occur along the experiment.
2.0 INTRODUCTION
Thermodynamics is a branch of study of physics that deals with the interchange of
energies such as work and heat between a system and a surrounding when the system
undergoes a process which are either cooling or heating. The loss or gain of energy of the
system during a process has a direct impact on the thermodynamics properties. Two of the
most important thermodynamics properties that are being investigated in this experiment are
absolute pressure and temperature that are both changes during the process in the system. The
data from the experiment will be compared with the theoretical value obtained from the steam
table.
For the purpose of this experiment, we will be using SOLTEQ®Marcet Boiler (Model:
HE169) which is the bench top unit designed for the demonstration of the basic principal in
thermodynamics which is boiling. SOLTEQ®Marcet Boiler (Model: HE169) are the most
common device used for students in the laboratory in order for them to have a better
understanding the relationship between absolute pressure and temperature of saturated steam
in equilibrium with water.
3.0 OBJECTIVE
The main objective of this experiment isto determine the saturation pressure curve at the
pressure within 10bar (150lb/in2). This experiment is also carried out to investigate between
the pressure and temperature of saturated steam in equilibrium with water. Then, by using the
data from the experiment, construct a graph for a function of temperature against the absolute
pressure and calculate the slope of the curve (dT/dP). Next, the results from this experiment
will be compared with the theoretical value obtained from the steam table. However, we may
not be able to get an accurate value of data as it might have errors during the experiment.
4.0 THEORY
The use of Marcet Boiler is to investigate the relationship between a saturated pressure
and the temperature of water between ranges of 0-14 bar. By using the Marcet Boiler, we can
observe that as the temperature of water increases, the pressure also increases. Thus, the
temperature of water is said to be directly proportional with the pressure.
Thermodynamics is a study related between energy and entropy, which is also deal with
heat and work. It is a set of theories that related to macroscopic properties, visible with naked
eye which we can measure the volume, pressure and temperature.
Ideal gas law is a law in which related to pressure, temperature and also volume of an
ideal gas. Ideal gas law is originally derived experimentally measured from Charles’s Law
and Boyle’s Law. Let P is pressure of a gas, V is a volume it occupies and T is it temperature
which is in Kelvin, K. The ideal gas law state that
PV = nRT
Where,
P = Absolute pressure, kPa
V = Volume, m³
n = Amount of substances, moles
R = Ideal gas constant, kJ/kg.K
T = Absolute temperature, K
The measured value of the slope of a graph (dT/dP)SAT can be obtained from the data
of result from the experiment done and compare it with corresponding values calculated from
the steam tables.
�
�
�
�
SAT
=
�Vfg
fg
� �f − �g
SAT =
f− g
And hf + hfg= hg
Hence, hfg = hg – hf
As Vg>>Vf
Where ,





Vf
Vg
hf
hg
hfg
�
�
SAT
=
� �f − �g
fg
= specific volume of saturated liquid
= specific volume of saturated vapour
= enthalpy of saturated liquid
= enthalpy of saturated vapour
= latent heat of vaporization
=
�Vg
fg
5.0 APPARATUS AND MATERIAL

Material : Distilled water

Apparatus :
6
1
2
7
3
8
4
9
10
5
Figure 1 : Unit Construction for Marcet Boiler (Model : HE169)
No
1.
Apparatus
Pressure Transducer
2.
Pressure Indicator
3.
Temperature Indicator/Controller
4.
Control Panel
5.
Bench
6.
Bourdon Tube Pressure Gauge
7.
Temperature Sensor
8.
Pressure Relief Valve
9.
Heater
10.
Water Inlet Port & Valve
6.0 METHODOLOGY
General Operating Procedures

General Start-up Procedures
1) Perform a quick inspection to ensure that the unit was in a proper operating
condition.
2) Connect the unit to the nearest power supply.
3) Inspect whether water was already filled in the boiler. If water had been filled
in the boiler, skip step no 4 and 5.
4) Open the valves at the feed port and the level sight tube (V1, V2 and V3).
5) Fill in the boiler with distilled water through the feed port and make sure that
the water was at about half of the boilers height. Then, close the valves, V1
and V2 at the level sight tube.
6) Turn on the power supply switch.
7) Carry out the experiment.

General Shut-down Procedures
1) Switch off the heater and allow the boiler temperature to drop until room
temperature.
2) When the temperature had dropped down to a room temperature, switch off
the main switch and the main power supply.
3) Retain the water for the next use.
4) To drain off the water, open the upper part of the level sight tube, V3 and then
open V1 and V2 to drain off the water.
Note : Do not open the valve at the water inlet port as it was highly
pressurized at a higher temperature.
Experimental Procedure
1) Perform the general start-up procedures
2) If the boiler was initially filled with water, open the valves at the level sight tube (V2
and V3) to check the water level. Pour in additional distilled water if necessary. Then,
close the valves.
3) Set the temperature controller to 185.0 °C which was slightly above the expected
boiling point of the water at 10.0 bar (absolute pressure).
4) Open the vent valve, V3 and turn on the heater.It is always important to ensure
that the valves at the level sight tube are closed before turning on the
heater as the level sight tube is not designed to withstand high pressure
and temperature.
5) Observe the steam temperature rise as the water boils.
6) Allow the steam to come out from the valve, V3 for about 30 seconds, and then close
the valve. This step was important to remove air from the boiler as the accuracy of the
experimental results will be significantly affected when air is present.
7) Record the steam temperature and pressure when the boiler is heated until the steam
pressure reaches 10.0 bar (absolute pressure). (Make the intervals of pressure data for
0.1 initially, followed by 0.2 and 0.5 for the following data).
8) Then, turn off the heater and the steam temperature and pressure will begin to drop.
Start to record the steam temperature when the boiler is cooled down until the steam
pressure reaches atmospheric pressure.
9) Allow the boiler to cool down to a room temperature.
10) Record the steam temperatures at different pressure readings when the boiler is heated
and cooled.
Warning : Never open the valve when boiler is heated as pressurized steam can cause
severe injury.
7.0 RESULT
Pressure, P
(bar)
Temperature, T
Gauge
Absolute
Increase
(ᵒC)
Decrease
(ᵒC)
Average
Tavc (ᵒC)
Average
Tavc(K)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1.10
1.20
1.30
1.40
1.50
1.60
1.70
1.80
1.90
2.00
2.50
3.00
3.50
4.00
4.50
5.00
5.50
6.00
6.50
7.00
7.50
8.00
8.50
9.00
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
100.60
101.70
102.20
104.90
107.00
109.10
111.30
113.20
115.0
116.80
118.40
120.10
121.60
123.10
124.50
126.00
127.30
128.60
129.90
131.00
132.20
137.6
142.50
146.80
150.80
154.40
157.80
161.00
164.00
166.80
169.50
172.00
174.50
176.90
179.10
99.90
102.60
105.00
107.40
109.40
111.70
113.70
115.50
117.30
119.00
120.60
122.10
123.6
125.10
126.50
127.80
129.10
130.30
131.50
132.80
133.90
139.20
143.90
148.30
152.20
155.80
159.20
162.40
165.50
168.30
170.90
173.40
175.80
177.80
179.10
100.25
102.15
103.60
106.15
108.20
110.40
112.50
114.35
116.15
117.90
119.50
121.10
122.60
124.10
125.50
126.90
128.20
129.45
130.70
131.90
133.05
138.40
143.20
147.55
151.50
155.10
158.50
161.70
164.75
167.55
170.20
172.70
175.15
177.35
179.10
373.25
375.15
376.60
379.15
381.20
383.40
385.50
387.35
389.15
390.90
392.50
394.10
395.60
397.10
398.50
399.90
401.20
402.45
403.70
404.90
406.05
411.40
416.20
420.55
424.50
428.10
431.50
434.70
437.75
440.55
443.20
445.70
448.15
450.35
452.10
Measured
slope,
dT/dP
Calculated
slope,
Tvg/hfg
0.190
0.145
0.255
0.205
0.220
0.210
0.185
0.180
0.175
0.160
0.160
0.150
0.150
0.140
0.140
0.130
0.125
0.125
0.120
0.115
0.107
0.096
0.087
0.079
0.072
0.068
0.064
0.061
0.056
0.053
0.050
0.049
0.044
0.035
0.2800
0.2600
0.2413
0.2257
0.2128
0.1997
0.1904
0.1809
0.1725
0.1653
0.1579
0.1522
0.1464
0.1412
0.1365
0.1318
0.1279
0.1255
0.1203
0.1171
0.1137
0.1004
0.0902
0.0821
0.0755
0.0700
0.0653
0.0613
0.0578
0.0547
0.0520
0.0496
0.0474
0.0455
0.0436
8.0 CALCULATION
Calculation for measured slope, (dT/dP) :Pressure, Pabs
(bar)
dP
(kPa)
Average Tavc
(K)
dT
(K)
(dT/dP)
(K/kPa)
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
50
50
50
50
50
50
50
50
50
50
50
50
50
50
373.25
375.15
376.60
379.15
381.20
383.40
385.50
387.35
389.15
390.90
392.50
394.10
395.60
397.10
398.50
399.90
401.20
402.45
403.75
404.90
406.05
411.40
416.20
420.55
424.50
428.10
431.50
434.70
437.75
440.55
443.20
445.70
448.15
450.35
452.10
1.9
1.45
2.55
2.05
2.20
2.10
1.85
1.80
1.75
1.60
1.60
1.50
1.50
1.40
1.40
1.30
1.25
1.25
1.20
1.15
5.35
4.80
4.35
3.95
3.60
3.40
3.20
3.05
2.80
2.65
2.50
2.45
2.20
1.75
0.190
0.145
0.255
0.205
0.220
0.210
0.185
0.180
0.175
0.160
0.160
0.150
0.150
0.140
0.140
0.130
0.125
0.125
0.120
0.115
0.107
0.096
0.087
0.079
0.072
0.068
0.064
0.061
0.056
0.053
0.050
0.049
0.044
0.035
Sample calculation for average temperature, Tavg :-
Average Temperature, Tavg =T increase + T decrease
2
= 100.6 ᵒC + 99.9 ᵒC
2
= 100.25 ᵒC
= 100.25 ᵒC + 273 K
= 373.25 K
Sample calculation for dP :-
dP 2.1 bar = Pabs @ 2.1 bar – Pabs @ 1.1 bar
= 2.1 bar – 1.1 bar
= 1.0 bar
= 1.0 bar × 100 kPa
1 bar
= 100 kPa
Sample calculation for dT :dT2.1 bar = Tavg @ 2.1 bar - Tavg @ 1.1 bar
= 394.10 K – 374.56 K
= 19.54 K
Sample Calculation for (dT / dP) :-
(dT / dP) 1.5 bar = (dT 1.5 bar / dP 1.5 bar)
= 2.20/10
=0.22 K/kPa
Sample Calculation for Vf :-
150 kPa – 125 kPa
=
175 kPa – 125 kPa
Vf
Vf m³ / kg – 0.001048 m³ / kg
0.001057 m³/kg – 0.001048 m³/kg
=
0.0010525 m³ / kg
Sample Calculation for vg :-
150 kPa – 125 kPa
175 kPa – 125 kPa
Vg
=
=
Vg m³ / kg – 1.3750 m³ / kg
1.0037 m³ / kg – 1.3750 m³ / kg
1.18935 m³ / kg
Sample Calculation for Vfg :-
Vfg
=
=
Vfg
=
Vg – Vf
1.18935 m³ / kg – 0.0010525 m³ / kg
1.1882975 m³ / kg
Sample Calculation for enthalpy, hfg :-
150 kPa – 125 kPa
=
175 kPa – 125 kPa
hfg
hfg kJ/kg – 2240.6 kJ/kg
2213.1 kJ/kg – 2240.6 kJ/kg
=
2226.85 kJ/kg
Sample Calculation for Calculation Slope, (Tvfg / hfg) :-
(Tvfg / hfg)
=
(383.40 K) (1.1882975 m³ / kg)
2226.85 kJ/kg
=
0.20459 m³ K / kJ
X
1 kJ
1 kPa.m³
=
0.20459 K / kPa
Calculation for calculated slope, (�� /
) :-
Pressure, P
(bar)
Temperature,T
(K)
Specific
volume, v
(m3/kg)
Enthalphy, h
(kJ/kg)
Gauge Absolute
Average Tavc
Vg
hfg
373.25
375.15
376.60
379.15
381.20
383.40
385.50
387.35
389.15
390.90
392.50
394.10
1.6941
1.5540
1.4340
1.3320
1.2456
1.1594
1.0971
1.0348
0.9801
0.9329
0.8858
0.8488
2257.50
2250.14
2243.78
2237.68
2231.84
2226.00
2220.84
2215.68
2210.80
2206.20
2201.60
2197.36
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1.10
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
Calculated
slope,
(�vg/ fg)
0.2800
0.2600
0.2413
0.2257
0.2128
0.1997
0.1904
0.1809
0.1725
0.1653
0.1579
0.1522
1.20
1.30
1.40
1.50
1.60
1.70
1.80
1.90
2.00
2.50
3.00
3.50
4.00
4.50
5.00
5.50
6.00
6.50
7.00
7.50
8.00
8.50
9.00
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
395.60
397.10
398.50
399.90
401.20
402.45
403.75
404.90
406.05
411.40
416.20
420.55
424.50
428.10
431.50
434.70
437.75
440.55
443.20
445.70
448.15
450.35
452.10
0.8118
0.7784
0.7486
0.7187
0.6942
0.6696
0.6470
0.6264
0.6058
0.5242
0.4624
0.4139
0.3748
0.3426
0.3156
0.2926
0.2728
0.2555
0.2404
0.2269
0.2149
0.2041
0.1944
2193.12
2189.04
2185.12
2181.20
2177.52
2173.84
2170.30
2166.90
2163.50
2147.70
2133.40
2120.30
2108.00
2096.60
2085.80
2075.50
2065.80
2056.40
2047.50
2038.80
2030.50
2022.40
2014.60
0.1464
0.1412
0.1365
0.1318
0.1279
0.1255
0.1203
0.1171
0.1137
0.1004
0.0902
0.0821
0.0755
0.0700
0.0653
0.0613
0.0578
0.0547
0.0520
0.0496
0.0474
0.0455
0.0436
Sample calculation for percentage error, % :�
,% =
=
�
−
�
�
0.1130 − 0.1518
� 100%
0.1130
�
� 100%
= -34.34%
Calculated slope,
� fg
fg
(K/kPa)
Measured slope,
�
�
�
��
(K/kPa)
0.2800
0.2600
0.2413
0.2257
0.2128
0.1997
0.190
0.145
0.255
0.205
0.220
Percentage error
(%)
-36.84
-66.41
11.49
-3.80
9.23
0.1904
0.1809
0.1725
0.1653
0.1579
0.1522
0.1464
0.1412
0.1365
0.1318
0.1279
0.1255
0.1203
0.1171
0.1137
0.1004
0.0902
0.0821
0.0755
0.0700
0.0653
0.0613
0.0578
0.0547
0.0520
0.0496
0.0474
0.0455
0.0436
0.210
0.185
0.180
0.175
0.160
0.160
0.150
0.150
0.140
0.140
0.130
0.125
0.125
0.120
0.115
0.107
0.096
0.087
0.079
0.072
0.068
0.064
0.061
0.056
0.053
0.050
0.049
0.044
0.035
9.33
2.22
4.17
5.54
1.31
4.88
2.40
5.87
2.50
5.86
1.62
-0.4
3.76
2.42
1.13
6.17
6.04
5.63
4.43
2.78
3.97
4.22
5.25
2.32
1.89
0.80
3.27
-0.03
Measured slope against Calculated Slope
0.3
0.25
Slope
0.2
0.15
measured slope
0.1
calculated slope
0.05
0
1
1.2 1.4 1.6 1.8
2
2.2 2.4 2.6 2.8
3
4
5
6
7
8
9
10
Absolute Pressure,P, (Bar)
Average Temperature (K) against Absolute Pressure,P,(bar)
500
450
350
300
250
200
150
100
50
0
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
Average Temperature (K)
400
Absolute Pressure,P,(bar)
9.0 DISCUSSION
1. Before the experiment is conducted, it is vital to remove the air from the boiler. This
is because, air might affects the accuracy of the experimental results. If the air is not
removed, the correct equilibrium measurements between the steam and the boiling
water will not be obtained. Due to the partial pressure of air, a lower water
temperature will be required to raise the pressure. Besides, the air trapped in the boiler
could lead to boiler failure.
2.
Measured slope against Calculated Slope
0.3
0.25
Slope
0.2
0.15
measured slope
calculated slope
0.1
0.05
0
1
1.2 1.4 1.6 1.8
2
2.2 2.4 2.6 2.8
3
4
Absolute Pressure,P, (Bar)
5
6
7
8
9
10
Average Temperature (K) against Absolute Pressure,P,(bar)
500
450
Average Temperature (K)
400
350
300
250
200
150
100
50
0
1 1.11.21.31.41.51.61.71.81.9 2 2.12.22.32.42.52.62.72.82.9 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10
Absolute Pressure,P,(bar)
3. The error percentage should not cross or exceed 10% as the experiment was done in
enclosed surface and no volume of experimenting samples are allowed to escape
from the system. However, based on the data obtained from experiment, the
percentage of errors is within the range of -35 % – 41 %. The percentage error for
the experiment shows that the experimental yield was too much when the percentage
error is negative. Differ when the percentage of error is positive, it shows that the
experimental yield less than the theoretical yield. This might happen due to the
present of air in the boiler and the measurements reading errors that happen during
the experiment.
There are several sources of error of the experiment:I.
Measurement reading accuracy.
II.
Room temperature and pressure.
III.
The stability of the material.
IV.
The calculations of the data obtained.
In order to make sure the accuracy of the data obtained, we must avoid the
measurements reading errors.
4. When the water in the boiler is heated up, the liquid molecules started to gain heat and
move faster. As they move around so fast that they can not even hold on to each other
anymore, all the molecules started to flying apart and becoming gas. As the liquid
absorbed enough heat energy, it changes from liquid form to vapour form. However,
as the steam is not allowed to exit, the pressure in the boiler increases. Thus, causing
the temperature rise. The liquid (water) undergoes evaporation and becomes gas
(steam).
5. The boilers in the industries include :

Power plant boiler
The boiler generates high pressure steam by transferring heat of combustion in
various heat transfer sections. Volume of one unit mass of steam is thousand
times that of water. When water is converted to a steam in a closed vessel, the
pressure will increase. Heat the water from a cold condition to a boiling point
or saturation temperature. Water boils at saturation temperature to produce
steam. Heating steam from saturation temperature to higher temperature called

superheating to increase the power plant output and efficiency.
Food steamer used by food industries
There are two types of food steamers used by the food industry to heat food in
large quantities. The traditional design uses steam trays connected to a central
boiler. Newer technology uses individual heating systems to create the steam
on each set of steam trays. The newer technology offers significant advantages
in both energy and water efficiency. The boiler-based steamers utilize a boiler
to inject (through pipes) steam into the heating compartment containing the
food trays. Steam that does not condense on the food product escapes as a
mixture of steam and hot condensate through a drain at the bottom of the set of
steam trays. Not only is water wasted in the rejected steam, but also a
substantial amount of additional water is required to condense this steam and
cool the condensate water to an acceptable temperature before it enters the
sewer system

Fluidized bed reactor
The fuel is fluidized in oxygen and steam or air. The ash is removed dry or as
heavy agglomerates that defluidize. The temperatures are relatively low in dry
ash gasifiers, so the fuel must be highly reactive; low-grade coals are
particularly suitable. The agglomerating gasifiers have slightly higher
temperatures, and are suitable for higher rank coals. Fuel throughput is higher
than for the fixed bed, but not as high as for the entrained flow gasifier. The
conversion efficiency can be rather low due to elutriation of carbonaceous
material. Recycle or subsequent combustion of solids can be used to increase
conversion. Fluidized bed gasifiers are most useful for fuels that form highly
corrosive ash that would damage the walls of slagging gasifiers. Biomass fuels
generally contain high levels of corrosive ash.

Steam engines
Steam engines are external combustion engines, where the working fluid is
separate from the combustion products. Non-combustion heat sources such as
solar power, nuclear power or geothermal energy may be used. The ideal
thermodynamic cycle used to analyse this process is called the Rankine cycle.
In the cycle, water is heated and transforms into steam within a boiler
operating at a high pressure. When expanded through pistons or turbines,
mechanical work is done. The reduced-pressure steam is then condensed and
pumped back into the boiler.
10.0 CONCLUSION
Marcet boiler is a device which we use to study the relationship between pressure and
temperature for water at saturated liquid phase. As what we did in the laboratory, we started
the experiment by heating water with constant pressure until it reached boiling point. Then,
close the valve which creates a constant volume system which will forced the pressure to
increase as the temperature rises. And thus enable us to study the direct relationship between
pressure and temperature for water at that point.
We notice that it is essential to close the valve as it reached the boiling point to ensure
that we are now in a constant volume process or otherwise pressure would have never
increased and this will result the experiment to be useless.
We also notice that weclosed the valve exactly when we reached the boiling
temperature and thus keeping the water at a saturated liquid phase.
After studying the results and plotting the diagram, we find out that the relationship
between pressure and temperature is directly proportional. The difference between the
theoretical values and the actual values is caused by errors with certain calculated acceptable
percentages. In this experiment, the relationship between pressure and temperature is found to
be directly proportional. When compared to the theoretical slope, the experimental slope
shows a small deviation between them because of certain errors.
11.0 RECOMMENDATIONS
There are many ways for minor error can occur in the data from this lab. The first
recommendation is to check and rectify any leaks at the boiler. This is to ensure an accurate
reading is recorded throughout the experiment. The second recommendation is use only
distilled water for this experiment. The reason is to maintain the boiler’s life from rusting and
any damage. The third recommendation would be it is not necessary to drain the water from
the boiler. This is because there is no rusting element in the boiler that can cause major
damage to equipment. Lastly, it is recommend not to touch the hot component of the unit. Be
more alert and careful when handling the boiler. This could cause some serious injury if the
safety is taken for granted throughout the experiment
12.0 REFERENCES
1) Yunus A. Cengal& Michael A. Boles, “Thermodynamics – An Engineering
Approach”, 3rd Edition, 4th Edition, McGraw Hill, 2002.
2) James, T., Fatigue Failure for Dummies, Made Up Press, New York, 2nd Ed (1999),
pp.23
3) Davis, J., Metals Handbook, Vol 2, 10th Ed., ASM International, 1990, pp.145-165
13.0 APPENDIX
Pressure, P
(bar)
Temperature, T
Gauge
Absolute
Increase
(ᵒC)
Decrease
(ᵒC)
Average
Tavc (ᵒC)
Average
Tavc(K)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1.10
1.20
1.30
1.40
1.50
1.60
1.70
1.80
1.90
2.00
2.50
3.00
3.50
4.00
4.50
5.00
5.50
6.00
6.50
7.00
7.50
8.00
8.50
9.00
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
100.60
101.70
102.20
104.90
107.00
109.10
111.30
113.20
115.0
116.80
118.40
120.10
121.60
123.10
124.50
126.00
127.30
128.60
129.90
131.00
132.20
137.6
142.50
146.80
150.80
154.40
157.80
161.00
164.00
166.80
169.50
172.00
174.50
176.90
179.10
99.90
102.60
105.00
107.40
109.40
111.70
113.70
115.50
117.30
119.00
120.60
122.10
123.6
125.10
126.50
127.80
129.10
130.30
131.50
132.80
133.90
139.20
143.90
148.30
152.20
155.80
159.20
162.40
165.50
168.30
170.90
173.40
175.80
177.80
179.10
100.25
102.15
103.60
106.15
108.20
110.40
112.50
114.35
116.15
117.90
119.50
121.10
122.60
124.10
125.50
126.90
128.20
129.45
130.70
131.90
133.05
138.40
143.20
147.55
151.50
155.10
158.50
161.70
164.75
167.55
170.20
172.70
175.15
177.35
179.10
373.25
375.15
376.60
379.15
381.20
383.40
385.50
387.35
389.15
390.90
392.50
394.10
395.60
397.10
398.50
399.90
401.20
402.45
403.70
404.90
406.05
411.40
416.20
420.55
424.50
428.10
431.50
434.70
437.75
440.55
443.20
445.70
448.15
450.35
452.10
Measured
slope,
dT/dP
Calculated
slope,
Tvg/hfg
0.190
0.145
0.255
0.205
0.220
0.210
0.185
0.180
0.175
0.160
0.160
0.150
0.150
0.140
0.140
0.130
0.125
0.125
0.120
0.115
0.107
0.096
0.087
0.079
0.072
0.068
0.064
0.061
0.056
0.053
0.050
0.049
0.044
0.035
0.2800
0.2600
0.2413
0.2257
0.2128
0.1997
0.1904
0.1809
0.1725
0.1653
0.1579
0.1522
0.1464
0.1412
0.1365
0.1318
0.1279
0.1255
0.1203
0.1171
0.1137
0.1004
0.0902
0.0821
0.0755
0.0700
0.0653
0.0613
0.0578
0.0547
0.0520
0.0496
0.0474
0.0455
0.0436