PASCO TD-8572 User manual

Instruction Manual and
Experiment Guide for the
PASCO scientific
Model TD-8572
HEAT ENGINE/ GAS LAW
APPARATUS
bel/ar
a1 I" ~.J". ® 10101 Foothil/s Blvd.· Roseville, CA 95678-9011 USA
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teach science
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012-06014C Heat Engine/Gas Law Apparatus
Introduction
II II
TheP ASCO TD-8572 HeatEngine/Gas Law Apparatus is
usedfor quantitative experirnents involving the Ideal Gas
Law (as described below) and for investigations of a
work:ing heat engine. The equipment allows the amount
ofwork done by thermal energy to be measured.
The heart
ofthis apparatus is a nearly friction-free pistonl
cylinder system. The graphite piston fits snugly into a
precision-groundPyrex cylinderso thatthe system
produces almost friction-free motionandnegligible
leakage.
I
mass platform for adding ____
a load to do work .... ----11 ...
experiments li
precision-borepyrex
cylinder inside a
protective plastic shield
two port shut-off
valves
~ piston-holding
thumbscrew
millimeter scale for
measuring piston
displacement
Figure 1. Base apparatus
The HeatEngine/Gas Law Apparatus is designedwith
two pressureports with quick-connect fittings for connect-
ing to the air chamber tubing.
The apparatus can
be connectedto a Low Pressure Sensor
for usewithP
ASCO computerinterfaces.
A Do not apply lubricant to the piston or
~ cylinder.
A
Do not immerse the base apparatus in
liquido
A Note:
Use onlynon-caustic/non-toxic gases
such as air
or helium.
Equipment
I
The apparatus incIudes the following equiprnent
• base apparatus (Figure 1)
-piston diameter: 32.5
mm ± 0.1
-mass ofpiston andplatform: 35.0 g ± .06
air chamber (Figure 2)
3 hose configurations: onewith one-way check
valves and one with a clamp (Figure 2), and one
plainpiece
of tubing (not shown)
1 each, one-holed and two-holedrubber stopper
one-way
check valves
pressure port mating connectors
./ tubingfor
./ connecting
chamberto
cylinder
Figure 2. Air charnber and tubing
Always release the tubing clamps prior to
storage to avoidpermanently deforming the
tubing.
A Maxirnum Pressure: 345 kPa.
II

012-060J4C Heat Engine/Gas Law Apparatus
Experiment 1: Operation of a HeatEngine
EquipmentRequired: .
• Heat Engine/Gas Law Apparatas container
ofhot water I
.container
of ice water I
. 100
200gmass
Equiprnent Setup
(j) Using the one-holed stopper, connectthe tubing
with the one-way valves to the air chamber and
to a connecting
pon on the base assembly.
(lJ Closethe shut-offvalve on the tubing from the
ullused
porto
@ Set a mass of 100 to 200 g on the mass platform.
,... Note:
Use a maximum mass of200 grams in
the experirnent. A larger mass will cause the
valve seals to leak.
Procedure
(j) Move the air chamber from an ice water bath to a
hot water bath.
You will note that the air in the
chamberquickly expands throughthe tubing and
moves the piston up.
Note also that the one-way
check valve in the tubing connecting the base
apparatus and the airchamberpernuts air
to enter
the cylinder, while the otherone-way checkvalve
prevents air from leaving through the branched
tube.
Close lhe shul-off
valve on
lhe
tubing from lhe
unused porto
direclion of
airflow
Figure 1.1. Setup for the Heat Engine
Move the air chamber back to the coldbath and note that externai air is sucked into the air
chamberthrough the one-way valve located at the end
of the branched tube. Note also that the
one-way valve in the connecting tube prevents the air from escaping from the piston, so the
height
of thepiston remains the same.
Repeatsteps 3
and 4 until the mass has been completely lifted.
,... Note:
The greater the temperature differential between the hotand cold waterbaths, the
greater the lift achieved through each cycle through them.
3

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I
012-06014C Heat Engine/Gas Law Apparatus
Experiment2: Charles'Law II
EquipmentRequired:
• HeatEngine/Gas Law Apparatus .container
ofhot water I
.thennometer .ice I
Theory
Charles' law states that at a constant pressure, the volume of a fIxed mass or quantity of gas varies
directly with the absolute temperature:
V=cT (at constant P and where Tis expressed in degrees Kelvin)
Setup
(j) Using the one-holed stopper andplain tubing, connect the base apparatus and the air chamber.
Ql Close the shut-offvalve on the tubing from the unused porto
® Tum the base apparatus on its side. (In this position, the force acting on the apparatus is the
atmospheric pressure and is equal throughout the range
of operation ofthe piston.)
Close the shut-off valve on
lhelubing from lhe unused
porto
Add ice.
..
Do nol allow lhe lip oflhe
lhermomeler
lo louch lhe
botlom oflhe conlainer.
Hot
Procedure
CD Place the air chamber in a container of hotwater. Afier the chamber equilibrates to the
temperature, record the temperature and the height
ofthe piston.
Ql Add ice to the container and record the temperature and pressure at regular time intervals.
® Calculate the gas volumes atthe various pistonpositions you measured andmake a graph of plots
oftemperature versus volume. (Hint: The diameter
ofthe piston is 32.5 llli11.)
5
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012-06014C Heat EngineiGas Law Apparatus
Experiment 3: Boy/e's Law
EquipmentRequired:
.HeatEngine/Gas Law Apparatus .ScienceWorkshop computerinterface*
.Pressure Sensor (CI-6532)
*Fordetails on setting
up and operating the Pressure SensorwithScience Workshop, please
consult the instruction sheet for the Pressure Sensor and the User's Guide for Science Workshop.
Theory
Boyle's law states that the product of the volume of a gas times its pressure is a constant at a fixed
temperature:
PV a
Therefore, at a fixed temperature, the pressure will be inversely related to the volume, and the
relationship will be linear: a
p v
Setup
CD With the platform raised to its uppermost posi-
tion, connect the Pressure Sensor to a port on the
base apparatus with a short piece oftubing
(Figure
3.1).
Cf) Close the shut-offvalve 011 the tubing from the
u11used port.
G) Connect the Pressure Sensor to the computer
interface and set
up Scie11ce Workshop to record
pressure. Be sure that you set
up the keyboard
sampling option so you can enter height data by
hand. (Consult the Science Workshop User 's
Cuide, "Keyboard Sampling," for details.)
Procedure
(I) Record the height ofthe piston and the pressure
when the platfbrm
is raised to its highest position.
PressureSensor
Cf) Press the platform down to a series oflevels and
record
the height and pressure at each leveI.
G) Convertthe height measurements to gas vohune Figure 3.1. Experimental setup
measurements.
(Hint:
The diameter ofthe piston
is 32.5 rum.)
® Prepare a graph of pressure versus volume.
to compuler inleliace Close the shut-off
valve on
lhe lubing
from
lhe unused
pari.
,... Note: The relationship between pressure and volume may not be linear at pressures greater
than
120 kPa because of air leakage from the valves and ports at higher pressures.
7