PASCO TD-8579A User Manual

Instruction Manual and
Experiment Guide for the
PASCO scientific
Model TD-8579A

012-07599C

COMPUTER-BASED THERMAL

EXPANSION APPARATUS

© 2000 PASCO scientific

012-07599C Computer-based Thermal Expansion Apparatus

Table of Contents

Section Page

Copyright, Warranty and Equipment Return....................................................i i

INTRODUCTION ..........................................................................................1

EQUIPMENT..................................................................................................2

APPARATUS SETUP....................................................................................3

EXPERIMENT SETUP: ................................................................................. 4

Calibration...............................................................................................4

Software Setup........................................................................................4

EXPERIMENT: Measuring the Coefficient of Linear Expansion for Copper,
Brass, and Aluminum:

Introduction ...................................................................................... 5-6

Procedure ......................................................................................... 5-6

Data and Calculations ..........................................................................7

Questions .............................................................................................7

SAMPLE DATA ............................................................................................. 8

TROUBLESHOOTING .................................................................................9

ADDITIONAL OR REPLACEMENT PARTS .......................................... 10

TECHNICAL SUPPORT .............................................................................11

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Computer-based Thermal Expansion Apparatus 012-07599C

Copyright, Warranty and Equipment Return

Please—Feel free to duplicate this manual
subject to the copyright restrictions below.

Copyright Notice

The PASCO scientific 012-07599 Computer-based
Thermal Expansion Apparatus manual is copy­righted and all rights reserved. However, permis­sion is granted to non-profit educational institu­tions for reproduction of any part of the manual,
providing the reproductions are used only for their
laboratories and are not sold for profit. Reproduc­tion under any other circumstances, without the
written consent of PASCO scientific, is prohibited.

Limited Warranty

PASCO scientific warrants the product to be free
from defects in materials and workmanship for a
period of one year from the date of shipment to the
customer. PASCO will repair or replace at its option
any part of the product which is deemed to be defec­tive in material or workmanship. The warranty does
not cover damage to the product caused by abuse or
improper use. Determination of whether a product
failure is the result of a manufacturing defect or
improper use by the customer shall be made solely by
PASCO scientific. Responsibility for the return of
equipment for warranty repair belongs to the cus­tomer. Equipment must be properly packed to prevent
damage and shipped postage or freight prepaid.
(Damage caused by improper packing of the equip­ment for return shipment will not be covered by the
warranty.) Shipping costs for returning the equipment
after repair will be paid by PASCO scientific.

Equipment Return

Should the product have to be returned to PASCO
scientific for any reason, notify PASCO scientific by
letter, phone, or fax BEFORE returning the product.
Upon notification, the return authorization and
shipping instructions will be promptly issued.

➤ ➤

➤ NOTE: NO EQUIPMENT WILL BE

➤ ➤

ACCEPTED FOR RETURN WITHOUT AN
AUTHORIZATION FROM PASCO.

When returning equipment for repair, the units
must be packed properly. Carriers will not accept
responsibility for damage caused by improper
packing. To be certain the unit will not be damaged
in shipment, observe the following rules:

➀ The packing carton must be strong enough for

the item shipped.

➁ Make certain there are at least two inches of

packing material between any point on the appara­tus and the inside walls of the carton.

➂ Make certain that the packing material cannot

shift in the box or become compressed, allowing
the instrument to come in contact with the packing
carton.

Address: PASCO scientific

10101 Foothills Blvd.
Roseville, CA 95747-7100

Phone: [phone] (outside the U.S.)

Or

[phone]
FAX: [phone]
email: [e-mail]
web: www.pasco.com

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012-07599C Computer-based Thermal Expansion Apparatus

Introduction

Introduction

The PASCO Model TD-8579A Computer-based Thermal Expansion Apparatus provides easy and accurate
measurements for the coefficient of linear expansion for brass, copper, and aluminum. The PASCO
Model TD-8579A differs from the previous model TD-8578 in that it uses a Rotary Motion Sensor instead
of a dial gage for measuring length changes in the rod, a Thermistor Sensor instead of an ohmmeter, and
is compatible with a ScienceWorkshop® interface for recording sensor measurements in a computer.

The new PASCO CI-6527A Thermistor Sensor can be connected to the apparatus and a ScienceWorkshop
interface for viewing temperature readings inside DataStudio. With the new thermal expansion model,
students no longer have to convert resistance readings to temperature values using a conversion table.
DataStudio® provides immediate temperature feedback in either absolute temperature (degrees Kelvin),
degrees Celsius (C) or Fahrenheit (F). A setup diskette comes with the apparatus, which includes the pre­defined variables and equations for measuring temperature in degrees Celsius.

For the length measurement, the brass, copper, or aluminum tube is placed on the expansion base. The
length of the tube is measured at room temperature, then steam is passed through it. The expansion of the
length of the metal rod is measured with 0.006 mm resolution using the Rotary Motion Sensor. Tempera­tures are measured to within
the expansion of the metals at additional temperatures, hot or cold water can be passed through the metal
tubes.

+0.2 °C using a thermistor attached to the center of the tube. To investigate

Complete step-by-step instructions and a data sheet for results are provided in this manual.

Temperature Measurement with the Thermistor and Thermistor Sensor

A thermistor's resistance varies reliably with temperature. Typically, as the temperature of a metal rod
increases, the resistance decreases proportionally until the temperature equilibrates. Although the relation­ship between temperature and resistance is not linear, a linear approximation can be accurately used to
interpolate between table data points with an accuracy of approximately +0.2 0C.

The 10 kΩ thermistor used to measure the rod's temperature is embedded in the thermistor lug. Once
thermal equilibrium has been reached, the heat is highly uniform along the length of the rod. The foam
insulator is used to inhibit heat loss through the thermistor lug so the lug temperature closely follows the
rod's temperature. The insulator does not have any appreciable effect on the local temperature of the rod
itself.

Using the PASCO Thermistor Sensor with a ScienceWorkshop interface, the resistance is measured and
directly converted to a temperature measurement, which displays in DataStudio.

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Computer-based Thermal Expansion Apparatus 012-07599C

Equipment

Equipment Included:

The TD-8579A Computer-based Thermal Expansion Apparatus includes:

• A 40-cm long expansion base with 10 kΩ thermistor

• 3 metal rods — brass, copper (99.5% Cu, 0.5% Te), and aluminum (98.9% Al, 0.7% Mg, 0.4%

Si): 6.4 mm outside diameter

• 1 foam insulator to avoid heat loss at the thermistor connection point

• Thermoplastic elastometer tubing with 6.4mm I.D.

• A 3.5 in. experiment setup diskette

• 1 pinion (6:1 ratio of disk radius to pin radius) for the Rotary Motion Sensor, Model CI-6538

• 1 stereo-to-dual banana plug cable for connecting a Thermistor Sensor (CI-5627A)

spring clip

aluminum rod

spring clamp

thermistor

brass rod

Expansion base

Thermal Expansion Apparatus (TD-8579A)

Stereo-to-dual banana plug cable for
connecting Thermistor Sensor (CI-6527A)

copper rod

copper and
brass rod

plastic tubing

6:1 ratio pinion for
a Rotary Motion
Sensor

Additional Equipment Required

In addition to the TD-8579A Thermal Expansion Apparatus, you need the following
items to perform the experiment, which is described on pages 5-6 of this manual:

• ScienceWorkshop Interface (500, 700 or 750)

• DataStudio®, version 1.5.2 or later

• PASCO Thermistor Sensor, Model No. CI-6527A

SETUP

013-07638

setup
diskette

foam wrap

• PASCO Rotary Motion Sensor, Model No. CI-6538

• A source of steam or hot water, such as the PASCO Model TD-8556A Steam

Generator

• A metric measuring tape or ruler

• A tube clamp to block off one side of the tubing from the Steam Generator

• A container to catch the water as it drains out of the metal rod

• Optional: If additional data points are desired, you will also need a source of

hot or cold water.

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