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VERNIER SOFTWARE
PHYSICS WITH
THE TI CBL AND TI-82, TI-83, TI-85, TI-86, and TI-92
I. OVERVIEW
II. MEMORY REQUIREMENTS AND MAXIMUM DATA
III. GROUP FILES
IV. SENDING GROUP FILES
V. UNGROUPING FILES
VI. PROTECTED PROGRAM FILES
VII. GENERAL DESCRIPTION OF THE PHYSICS PROGRAMS
VIII. PERFORMING EXPERIMENTS WITH THE MICROPHONE
IX. GENERAL DESCRIPTION OF THE TIMER PROGRAMS
X. OVERVIEW OF EACH PROGRAM
XI. PROGRAM DESIGN NOTES
I. OVERVIEW
This document describes the use of two sets of programs that help
you perform experiments with a TI graphing calculator and the TI
Calculator-Based Laboratory (CBL) System with Vernier sensors
commonly used in physics. The PHYSICS set of programs support the
motion detector and analog sensors, i.e. force sensor,
accelerometer, microphone, and etc. The TIMER programs support
photogates and Smart Pulleys.
With the PHYSICS set of programs you will be able to use a motion
detector, force sensors, accelerometers, microphones, pressure
sensors, temperature probes, light sensors, voltage leads,
current probes, etc. Data collection modes can be used to 1)
monitor CBL channels, 2) collect data as a function of time, 3)
collect data with a manually-entered independent variable, and 4)
collect data using the trigger button on the CBL. Time graphs
generated in real time are possible but this option only works
when one or more of the same probe are active. If the active
probe is the Motion Detector, a live graph of distance vs. time
is drawn and neither velocity nor acceleration data will be
calculated. When more than one different sensor is active or when
you want distance, velocity and acceleration from the Motion
Detector, the time graphs will be displayed after the data is
collected. When the Motion Detector is used in conjunction with
the other sensors, only two of these probes can be active. This
occurs because the TI-82 is limited to six lists and the motion
data uses four lists. The programs on the other calculators are
prevented from using more than 3 probes to keep the programs
consistent. One of the features of the calculator is the ability
to model data with different regression models. In working with
real data, it is helpful to select a region of data with which to
work. Since the calculator applies the regression models to the
entire list, the calculated fit may be affected by unwanted data.
With this program it is possible to select a region of the graph
and automatically delete unwanted data outside the region of
interest for each of the data lists.
The TIMER set of programs support Vernier Software Photogates,
PASCO Photogates and PASCO Smart Pulleys in three different modes
of operation. The photogates and Smart Pulley require an adapter
(order code CBL-P for a single photogate or CBL-2P for two
photogates) available from Vernier Software. Note: These programs
will not work with the TI light probe.
II. MEMORY REQUIREMENTS
It is possible that you may run into "memory error" problems when
using these sets of programs. These errors may occur for two
reasons.
1) This entire set of programs will require a considerable amount
of the available memory on the calculator.
2) If you use a motion detector in combination with other probes,
large amounts of data may be collected.
If you run into memory errors, you may have to collect less data
or you may have to free up calculator memory by deleting lists,
matrices, pictures and/or programs. If there are certain data
collection modes in PHYSICS you are not using e.g. trigger, you
can delete programs associated with these modes-PHZTRIGG in this
example. (You will find a description of each program later in
this document.) You may also want to consider deleting the
PHZMICRO program if you are not going to use the microphone. If
you are not going to be using photogates, you can delete TIMER
and all the sub-programs that begin with TM. If you aren't going
to be using the PHYSICS part of the program, you can delete
PHYSICS and all the sub-programs that begin with PHZ. Refer to
your calculator manual for specific information on deleting
programs.
If you reset your calculator, then load the PHYSICST group file
(or PHYSICS on the TI-85) group file, the maximum number of
points you can collect with two probes and a motion detector on
the TI-82 is 99, the TI-83 120, the TI-85 55, the TI-86 512, and
the TI-92 190.
III. GROUP FILES
The PHYSICST group file is thirteen programs that have been
grouped together. Groups of files for the TI calculator always
have a "??g" suffix where "??" represents the various
calculators: 82, 83, 85, 86, or 92. Individual program files have
the extensions "??p" The extensions on the filenames appear only
on the computer and do not appear when you see the program names
on the calculator. The easiest method of loading all thirteen
programs on to your calculator is to transfer the PHYSICST.??g
group file. Note: On the TI-85, all the programs will not fit on
the calculator at the same time, therefore there are two group
files, PHYSICS.85g with the physics parts of the program, and
PHOTGATE.85g with the photogate parts of program.
IV. SENDING GROUP FILES
You will need to use TI-Graph Link to send the PHYSICST.??g group
file to your calculator. The actual steps will depend upon the
calculator and computer you are using. If you are unsure of this
process, refer to the Graph Link manual for the calculator and
computer you will be using. Not all calculators are handled the
same.
V. UNGROUPING FILES
You may prefer to "ungroup" the PHYSICST.??g file for archiving
on a hard drive. Before you do that, it would be best to create a
folder or subdirectory on your hard drive for the group file. The
programs can then be stored in a common area on your hard drive
after being ungrouped. The files can be ungrouped by choosing the
Ungroup Files option in the TI-GRAPH LINK program. Ungrouping the
file will make the following thirteen programs available:
PHYSICS, PHZCALIB, PHZCALS, PHZGRAPH, PHZMICRO, PHZMONIT,
PHZOPTIO, PHZTIMEG, PHZTRIGG, TIMER, TMGTSTAT, TMMOTION, TMGATE,
TMPENDLM, and TMPULSE. The TI-GRAPH LINK will also allow you to
download all thirteen programs from the computer to the
calculator.
VI. PROTECTED PROGRAM FILES
The calculator programs described, except for the TI-85, have
been protected so that they cannot be edited on the calculator.
This feature prevents students from accidentally corrupting a
program. The easiest way to edit protected files is with the
TI-GRAPH LINK program. The TI-GRAPH LINK manuals describe the
protecting and unprotecting process.
VII. GENERAL DESCRIPTION OF THE PHYSICS SET OF PROGRAMS
The PHYSICS program and its eight sub-programs (PHZCALIB,
PHZCALS, PHZGRAPH, PHZMICRO, PHZMONIT, PHZOPTIO, PHZTIMEG,
PHZTRIGG) programs function together to provide a wide range of
options as you create and run experiments. To begin, run the
PHYSICS program. You do not need to run the sub-programs because
PHYSICS calls them when necessary. The PHYSICS program uses a
series of menus allowing you to set up different types of
experiments with a combination of probes.
The following general description applies to the use of these
programs on your calculator. For specific help in executing
programs on the calculator, refer to the manual. To begin, run
the PHYSICS program. After an introductory screen, the following
MAIN MENU will appear:
***MAIN MENU***
1:SET UP PROBES
2:COLLECT DATA
3:VIEW GRAPH
4:RETRIEVE DATA
5:OPTIONS
6:QUIT
*****************************************************************
TI-85 and TI-86 users will see slightly different menus because
the TI-85 and TI-86 menus are limited to 5 elements in a menu,
also the menu items can only have 5 characters. The MAIN MENU on
the TI-85 or TI-86 will be:
***MAIN MENU***
SETUP=SET UP PROBES
COLL =COLLECT DATA
GRAPH=VIEW GRAPH
RETRI=RETRIEVE DATA
MORE =MORE
The MORE option will bring up this menu:
OPTIO=OPTIONS
QUIT =QUIT
RETRN=RETURN
The RETRN option will bring you back to the first part of the
MAIN MENU. When selecting MORE be sure to use the [F5] key, not
the [MORE] key on the calculator. NOTE: The menus in the
following description will match the TI-82, TI-83, and TI-92. The
TI-85 and TI-86 menus will differ slightly.
*****************************************************************
The CBL provides access to three analog channels, channels 1 - 3,
for devices such as force sensors, accelerometers, and
temperature probes. One sonic channel is available for an
ultrasonic motion detector. When you choose the first option, SET
UP PROBES, from the above menu, you will be able to 1) enter the
number of active probes, 2) choose a probe, 3) enter the CBL
channel number for any analog device, and 4) choose the method of
calibrating analog probes. If you are using a Motion Detector,
you will not be prompted for a channel number since the Motion
Detector will only work in the sonic channel. As you connect
analog probes to the CBL, connect each to the lowest available
channel. The program will limit the number of analog devices to
two when you are also using the Motion Detector. After you select
this option, the calculator will attempt to communicate with the
CBL. If the CBL is not powered up or the CBL and calculator are
not properly linked, an error message will appear. Check to see
that the link cord is firmly connected to each device and that
the CBL is powered up - press the [ON/HALT] button on the CBL.
Correct any problems before continuing. The calculator will then
ask you to enter the number of probes and then the following menu
will appear:
SELECT PROBE
1:MOTION
2:FORCE
3:ACCELEROMETER
4:MICROPHONE
5:PRESSURE
6:TEMPERATURE
7:MORE PROBES
The first option represents the Vernier Motion Detector. The
second option will bring up a menu from which you can choose the
Vernier Student Force Sensor, the Vernier Dual Range Force
Sensor, or the PASCO Force Sensor. The third option brings up a
menu from which you can choose the Low-g or 25-g Accelerometer.
The fourth option works with the CBL, MPLI, or ULI microphone.
(When you select this option, you will be sent to a subprogram to
collect data. This program is explained later.) The fifth option
represents the Pressure Sensor and the sixth option is used for
the TI Temperature Probe or the Vernier Direct-Connect
Temperature probe. Selecting Option 7 produces this list of
probes:
SELECT PROBE
1:LIGHT
2:MAGNETIC FIELD
3:VOLTAGE
4:C-V CURRENT
5:C-V VOLTAGE
6:THERMOCOUPLE
7:MORE PROBES
The first option can be used for either the TI Light Probe or the
Vernier Light Sensor. The second option represents the Magnetic
Field Sensor. The third option is used for either the TI Voltage
probe or the Vernier Voltage Leads. The fourth is used with the
Current and Voltage System Current Probe while the fifth option
represents the Current and Voltage System Voltage Probe. The
sixth option is used with the Thermocouple. Selecting Option 7
produces a final list of probes.
SELECT PROBE
1:VERN STD TEMP
2:VERN QIK TEMP
3:PHOTOGATE
4:RETURN
The first option refers to the Vernier Standard Temperature Probe
while the second option refers to the Vernier Quick-Response
Temperature Probe. The third option will take you to the TIMER
program which allows you to use photogates and Smart Pulleys with
the CBL. Option 4 returns you to the first list of probes.
The above lists will appear up to three times depending upon the
number of probes you entered. After you select an analog probe,
you will be asked to enter the channel number for that probe.
After you enter the channel number, you will be presented with
the following CALIBRATION menu:
**CALIBRATION**
1:USE STORED
2:PERFORM NEW
3:MANUAL ENTRY
The first option, USE STORED, in the above menu allows you to
load standard slope and intercept values for Vernier probes.
These are "generic" slope and intercept values determined by
Vernier Software. The values will provide reasonably accurate
measurements but individual probes differ and you may obtain
better results by performing a new calibration. (The PHZCALS
program contains the Vernier standard slope and intercept values.
It is possible to edit this program and enter the slope and
intercept values for your probes.)
If you choose to perform a new calibration, it is helpful to
understand the operation of Vernier probes other than the Motion
Detector. During their operation, the probes produce a voltage
that is linearly dependent upon a physical quantity. For example,
the Student Force Sensor produces a voltage that varies linearly
with the applied force. During the calibration process, the
computer establishes the linear relationship between voltage and
force. Choosing the PERFORM NEW option will allow you to perform
a two-point calibration for the probe that was just set up. The
following paragraph describes the calibration process for a
Student Force Sensor. The same general procedure can apply to the
any analog sensor.
After you choose the PERFORM NEW option from the above menu,
remove all forces from the Force Sensor. Monitor the CBL display
for the voltage produced by the probe. To monitor other channels,
press the [CH VIEW] button on the CBL. As you repeatedly press
and hold this button, you will be able to cycle through all the
channels. You will be able to see which channel is currently
being monitored by noting the blinking CH 1, CH 2, or CH 3
symbols in the upper left corner of the CBL display. When the
voltage stabilizes, press the [TRIGGER] button on the CBL. You
are then prompted to enter the reference value, 0 newtons in this
case. Apply a known force to the sensor as a second reference.
The easiest method is to hang a labeled mass from the beam end of
the sensor. For example, a 200-g mass weighs 1.96 N. The voltage
is again monitored and the [TRIGGER] button is pressed when the
voltage stabilizes. Enter the second reference value. A slope and
intercept for the linear calibration curve are then displayed on
the calculator and loaded into the CBL. You may want to record
these values for future reference (see the section below). This
process can be repeated for other Vernier probes. For further
help with other sensors and probes refer to the information sheet
for those devices.
Option 3, MANUAL ENTRY, in the Calibrate Menu is an option that
may save you time in setting up future experiments especially if
you have performed calibrations for your probes. Probes such as
the Force Sensor hold their calibration for long time periods. If
you know the slope and intercept values determined in the above
process, you can manually enter these values with this option.
After the channels and probes are set up, you will return to the
MAIN MENU. From the MAIN MENU you can set up an experiment by
choosing the second option, COLLECT DATA. The following menu
provides you with a choice of data-collection modes:
DATA COLLECTION
1:MONITOR INPUT
2:TIME GRAPH
3:TRIGGER/PROMPT
4:TRIGGER
5:RETURN
The MONITOR INPUT option is used to monitor the active channels
with the calculator. The purpose of this option is to view data
at approximately 1.0 second intervals. No data is stored. For all
probe combinations, each active channel will be displayed on the
calculator. When done monitoring the channels, press the [+] key
on the calculator to quit.
The TIME GRAPH option from the DATA COLLECTION menu is used to
collect data as a function of time. A screen will prompt you to
enter the time between samples which is entered in seconds. The
sample time can be in the following range of values: 0.000164 to
0.2 seconds or 0.25 to 16000 seconds. However, the minimum sample
time depends upon the number and types of active probes and the
data collection mode.
If you plan to use a live display where a graph is shown during
data collection and you only have one probe, the minimum sample
time is 0.1 s regardless of the type of probe. (If you enter a
time less than 0.1 seconds, you will not get a live display.) If
you enter a value between 0.1 s and 0.2 s and you use a live
display, the CBL will collect data at 0.1 s. If you have two
similar probes, the minimum sample time for a live display is 1
s. If you have three similar probes, the minimum sample time for
a live display is 1.25 s.
If you are going to collect data without a live display, the
minimum sample time for one analog probe is 0.000164 s. For two
analog probes the minimum time is 0.000264 and for three probes
it is 0.000364 s. The minimum sample time for the Motion Detector
with a non-live display is 0.008 s. (The minimum sample time will
increase by 0.0006 s if you use the manual trigger option, a
feature available in the OPTIONS menu.) If you enter a value less
than the minimum sample time, the calculator will use the minimum
sample time allowed for your setup. To automatically collect data
at the minimum sample time, enter 0 as the sample time.
After the sample time is entered, you will be prompted to enter
the number of data points. The maximum number on the TI-82 is 99,
on the other calculators it is 512, although you may be limited
by available memory. (See Section II for Memory Requirements.)
Under certain conditions (detailed below) the following menu will
appear allowing you to choose between live and non-live displays:
COLLECTION MODE
1:NON-LIVE DISPL
2:LIVE DISPLAY
This menu will appear under these conditions:
1) only one type of probe is active,
2) triggering is not being used to start data collection,
3) the sample time is greater than or equal to the minimum value
for a live display, and
4) the sample time is less than 270 s (4.5 minutes).
The NON-LIVE DISPL option will collect data without displaying a
graph during data collection. This option provides the greatest
flexibility in designing experiments by permitting combinations
of probes, triggering, and a wider range of sample times. (If you
did not see the above menu, the data will be collected without a
live display.) If the Motion Detector is active, only two analog
channels can be active. If you are only using analog channels,
you will see graphs of each channel when data collection is
complete. If the Motion Detector is the only active channel, then
you will be able to choose from three graphs: distance vs. time,
velocity vs. time, and acceleration vs. time. If you are using
the Motion Detector and analog probes, you will be able to choose
between the different analog channels and the different motion
data.
The LIVE DISPLAY option produces a "real-time" graph during data
collection. However, this option will only work with probes of
the same type and if the sample time is less than or equal to 270
seconds. Please note that the time base during data collection
with a live display is only approximate. To record an accurate
time base, use the Non-Live Display option.
If the experiment is longer than 270 seconds (4.5 minutes) and
non-live or you are using a manual trigger, the experiment is
considered to be a long-term experiment since the calculator will
automatically power down. A message will direct you to use the
RETRIEVE DATA option from the MAIN MENU. Select this option after
the data collection is complete when the CBL display shows
"DONE". After the option is chosen, the data will be retrieved
from the CBL and the graph or graphs will be displayed.
Each time you view a graph, you will be able to read off the
coordinates of each data point. The coordinates of the first
point will be displayed on the bottom of the screen. To view
other points use the left and right arrow buttons on the
calculator to move across the screen.
The TRIGGER/PROMPT option in the DATA COLLECTION menu is used to
perform experiments in which the independent variable is entered
from the calculator keyboard while the dependent variable is
measured with the CBL probe or probes. For example, you could use
a Light Sensor to measure the light intensity as the distance
from the source changes. When the [TRIGGER] button on the CBL is
pressed, the CBL measures the light intensity and you will be
prompted to enter the distance from the source.
After you select this option, a screen will appear prompting you
to press the CBL [TRIGGER] button when you are ready to take a
sample. You will then be prompted to enter the independent
variable. The following menu then appears:
DATA COLLECTION
1:MORE DATA
2:STOP AND GRAPH
3:PAUSE
If you select option 1:MORE DATA, the CBL will be set up to make
another reading. If you select option 2:STOP AND GRAPH, data
collection will stop and a graph will be displayed. If you select
option 3:PAUSE, the calculator will be put in a pause mode. When
you are ready to collect more data, press [ENTER] on the
calculator and follow the on-screen instructions. If the
calculator has powered down due to the APD, turn on the
calculator, then press the [ENTER] key.
The TRIGGER option in the DATA COLLECTION menu is used to
manually sample each active channel when the [TRIGGER] button on
the CBL is pressed. (In this data-collection mode, you do not
enter an independent variable as done in the TRIGGER/PROMPT
mode.) Each time you press the [TRIGGER] button, you will get the
following screen:
TRIGGER
1:CONTINUE
2:STOP
3:PAUSE
If you select option 1:CONTINUE, the CBL will be set up to make
another reading. If you select option 2:STOP, data collection
will stop and you will return to the MAIN MENU unless there are
two active probes in which case a graph will be drawn. If you
select option 3:PAUSE, the calculator will be put in a pause
mode. When you are ready to collect more data, press [ENTER] on
the calculator and follow the on-screen instructions. If the
calculator has powered down due to the APD, turn on the
calculator, then press the [ENTER] key.
During the data collection process in the TRIGGER/PROMPT and
TRIGGER modes you can monitor each active channel by pressing and
holding the [CH VIEW] button on the CBL. Repeated pressing of
this button will cycle you through the active channels.
The third option, VIEW GRAPH, on the MAIN MENU allows you to
review previously set up graphs. As you view each graph, you will
be able to use the left and right arrow buttons on the calculator
to view the coordinates of each point. These graphs use the
"ZoomStat" option to provide automatic scaling of axes. You may
prefer to quit the program to set your own scaling.
The fourth option on the MAIN MENU, RETRIEVE DATA, is used after
data is collected during a long-term experiment. Before you
select this option, be sure the CBL is done collecting data. (The
word "DONE" should appear in the CBL display.)
The fifth option, OPTIONS, in the MAIN MENU brings up this menu:
PHYSICS OPTIONS
1:SELECT REGION
2:INTEGRATE
3:MANUAL TRIGGER
4:TRIGGERING
5:ZERO SENSOR
6:RETURN
The first option SELECT REGION is used to select a portion of
data. This feature is helpful in deleting extraneous data thereby
making it easier to model data. After this option is selected, a
menu will appear asking you which graph you wish to examine. This
graph will then be displayed so that you may select a region of
data. Use the arrow keys to move the cursor and select the lower
limit of the region and press [ENTER]. A horizontal line will be
drawn on the graph. Now move the cursor to select the upper limit
and press [ENTER]. Data above and below these limits will be
deleted from ALL lists.
The second option, INTEGRATE, is used to integrate a section of
the graph. After selecting this option, choose a graph from the
list displayed on the screen that follows. Use the arrow keys to
move the cursor and select the lower limit of the region and
press [ENTER]. A horizontal line will be drawn on the graph. Now
move the cursor to select the upper limit and press [ENTER].
After the integration is performed, vertical lines will be drawn
to represent the integrated area. Press [ENTER] to see the
numerical results.
The third option, MANUAL TRIGGER, will bring up a menu asking you
if you wish to use a manual trigger. When you are performing a
time graph experiment with a manual trigger, the data will not be
collected until you press the [TRIGGER] button on the CBL. This
is helpful when you want to collect data while the CBL is
disconnected from the calculator. You can reconnect the
calculator to the CBL and use the RETRIEVE DATA option to
retrieve the data from the CBL, and then analyze the data on the
calculator. You should use this option after you have set up the
probes. If you set up probes after selecting this option, the CBL
will trigger automatically.
The fourth option, TRIGGERING, will set up the CBL to begin
collecting data when the signal from Channel 1 or 2 reaches a
certain value. You can trigger on any analog probe except the TI
temperature probe. After selecting this option, you will choose
the trigger channel. Next you will choose whether the measurement
is rising or falling. You will then enter the trigger value and
the amount of prestore data. This amount can be an integer
between 0 and 100. You should use this option after you have set
up the probes. If you set up probes after selecting this option,
the CBL will not wait for the trigger.
The fifth option, ZERO SENSOR, will bring up this menu:
SELECT CHANNEL
1:CHANNEL 1
2:CHANNEL 2
3:CHANNEL 3
4:MOTION
5:ALL CHANNELS
When you zero an analog probe, it acts like a tare button. When
you zero the motion detector, the measurements are made from a
reference point. Objects that are closer to the Motion Detector
than this reference point will be positive, things that are
farther away than this will be negative distances. If you select
option 5, ALL CHANNELS, all active probes will be zeroed. You
should use this option after you have set up the probes. If you
set up probes after selecting this option, the probes will use
the calibration you set them up to use.
The sixth option, RETURN, will return you to the main menu.
The sixth option in the MAIN MENU, QUIT, will exit the program.
DATA STORAGE
During data collection data is stored in the following lists:
time or independent variable in L1
motion detector
distance in L4
velocity in L5
acceleration in L6
analog channels
channel 1 in L2
channel 2 in L3
channel 3 in L4
During the data collection process you can monitor each active
channel by pressing and holding the [CH VIEW] button on the CBL.
Repeated pressing of this button will cycle you through the
active channels.
VIII. PERFORMING EXPERIMENTS WITH THE MICROPHONE
When you select the Microphone from the list of probes during
probe setup, a separate program will be run. The primary use of
this program is to produce waveform graphs of sound pressure as a
function of time. If you are using a CBL or MPLI Microphone you
will be able to monitor the frequency of a sound signal.
If waveform data is collected, it is possible to model the data
with a trigonometric function. The program defines equation Y1
with an appropriate form.
We have found that the best waveforms occur when the peak voltage
from the microphone is in the range of 0.5 to 1.0 volts. If the
signal is much smaller than that, the quality of the waveform
decreases. If this is the case, you may need to produce a louder
sound or move the source closer to the microphone. When the
waveforms are displayed by this program, you can use the arrow
buttons to trace the waveform and check the voltage of the signal
noting the maximum or minimum y values.
After choosing Microphone from the list of probes, a screen will
appear reminding you to connect the microphone to Channel 1. The
following screen will appear next and you will have to choose the
type of microphone you are using.
SELECT MICROPHN
1:CBL
2:ULI
3:MPLI
The next screen provides a list of data collection modes.
COLLECTION MODE
1:WAVEFORM
2:WAVEFORM/TRIGR
2:FREQUENCY
3:RETURN
If you choose Option 1, WAVEFORMS, a screen will appear prompting
you to hold a sound source close to the microphone. After you
press the [ENTER] key on the calculator, the CBL will quickly
sample the sound source. A display of sound pressure vs. time
will be displayed on the calculator and you can use the arrow
keys to trace data points on the graph. After you press [ENTER]
from the graph screen, you will be asked whether you want to
repeat the data collection. If not, you will return to the MAIN
MENU. During sampling the time is stored in list L1 and voltage
which is proportional to sound level is stored in list L2.
Option 2, WAVEFORM/TRIGR, also produces a waveform but this time
the CBL is placed in a trigger mode. The CBL will not start to
collect data until the voltage reaches 0.2 V. (Note: this mode
will only work with the CBL or MPLI microphone.) Once the trigger
occurs, sampling begins and a graph of sound pressure vs. time
will be displayed. After you select this option, a screen will
prompt you to press [ENTER] to make the CBL ready. The CBL will
then wait for a trigger. After the data is collected, the graph
will be displayed and you can use the arrow keys to trace the
data points on the graph. Again the time is stored in L1 and
sound level is stored in list L2.
Option 3, FREQUENCY, in the MAIN MENU will monitor a sound source
held near the microphone and display its frequency in hertz.
(Note: this mode will only work with the CBL or MPLI microphone.)
After you select the option, you will be instructed to press the
[ENTER] key to prepare the CBL to collect data. The next screen
will prompt you to hold a sound source close to the microphone.
When the sound intensity reaches a certain level, the CBL will be
triggered and the signal will be monitored. If the sound is weak,
you may have to hold the source very close to the microphone.
After a short time, the frequency will be displayed on the
calculator. The frequency will be stored in list L1. After you
press [ENTER], you will be given the opportunity to repeat the
data collection.
EDITING THE TIME BETWEEN SAMPLES
When waveforms are collected, this program is set up to collect
data as fast as possible. The minimum sample time in this
situation is 0.000165 s. You may want to change this value. This
is done by editing the Sample and Trigger Command (command 3) in
the PHZMICRO program. If you are collecting waveforms using
Option 1:WAVEFORMS, locate this command,
{3,0.000165,99,0,0,0,0,0,1,0}->L6 within the Lbl 1 section. If
you are collecting waveforms using Option 2:WAVEFORM/TRIGR,
locate this command {3,0.000165,99,2,1,.2,0,0,1,0}->L6, within
Lbl 2 section. To increase the time between samples, edit the
second number in these commands. For help in editing programs,
refer to the guidebook that came with the calculator.
IX. GENERAL DESCRIPTION OF THE TIMER PROGRAMS
The following general description applies to the use of the TIMER
set of programs on the calculator. For specific help in executing
programs on the calculator, refer to the manual. To begin, run
the TIMER program. After an introductory screen, the following
main menu will appear:
PHOTOGATE TIMING
1:TIMING MODES
2:CHECK GATE
3:QUIT
The first option, TIMING MODES, allows you to select different
methods for using photogates and photogate/pulley systems. The
next section describes this option. The second option, CHECK
GATES, provides a check of the photogate. Choosing this option
brings up a screen that displays the status of the photogate.
Slowly move an object through the photogate to verify that it
changes between the blocked and unblocked states. The third
option, QUIT, returns you to the Home Screen where you have
access to graphing and statistical analysis features.
After checking to see that the photogate works, select the TIMING
MODES option and the following menu will appear:
**TIMING MODES**
1:MOTION
2:GATE
3:PENDULUM
4:PULSE
5:RETURN
The first option, MOTION, allows you to use photogates and
photogate/pulley systems to collect data and view graphs of
distance, velocity and acceleration as a function of time. The
second option, SINGLE GATE, records the time that a photogate is
blocked. The PENDULUM option measures the period of a pendulum as
it travels back and forth through a photogate. Each of these
modes is described below.
When you select MOTION from the TIMING MODES menu, the following
menu appears:
*MOTION TIMING*
1:SELECT DEVICE
2:COLLECT DATA
3:VIEW GRAPHS
4:REPEAT
5:RETURN
The SELECT DEVICE option will produce another menu from which you
will choose an appropriate photogate device. The options are:
SELECT DEVICE
1:VERNIER PICKET
2:SMART PULLEY
3:CUSTOM DEVICE
4:RETURN
The VERNIER PICKET is a picket fence containing eight opaque bars
separated by seven clear bars. The distance between the leading
edges of the opaque bars is 0.05 m. Selecting the SMART PULLEY
option brings up a list of various photogate/pulley arrangements.
SMART PULLEY
1:10 SPOKE INSID
2:10 SPOKE OUTSI
3:3 SPOKE INSIDE
4:3 SPOKE OUTSID
These options refer to two different PASCO Smart Pulleys
(containing either three or ten spokes) operating in two
different modes. In one mode a string is pulled through the
groove in the pulley. In the other mode the pulley is spun by an
object on the outside edge of the pulley.
If you choose the CUSTOM DEVICE option in the SELECT DEVICE menu,
you will be asked to enter the number of opaque objects in the
picket fence or bar tape and the distance between leading edges.
After the device has been chosen, you will return to the MOTION
TIMING menu where you can now begin to collect data. If you have
selected a photogate/pulley, you will be asked to estimate the
number of revolutions. This estimate will tell the CBL when to
stop collecting data. Since the TI-82 calculator is limited to 99
elements in a list, you will be limited to the number of
rotations of the pulley. You may have to design your experiment
with this in mind if you are using the TI-82, the other
calculators are limited to 512 points.
After the data is collected you will have a chance to view
distance vs. time, velocity vs. time, and acceleration vs. time
graphs. As you view the graph, you will also be able to use the
left and right arrows to read off the coordinates of each data
point. After viewing these graphs, you will then have an
opportunity to repeat the experiment or return to TIMING MODES
menu. You can then return to the main PHOTOGATE TIMING menu.
Option two, GATE, in the TIMING MODES menu will measure the time
during which one or two photogates are blocked. After you select
this option, you will have to choose whether you are using one or
two gates. Then you will be directed to move an object through
the photogate to arm the gate. The CBL will now record the time
or times as the next object passes through the photogate(s).
Option three, PENDULUM, in the TIMING MODES menu will measure the
period of an object as it oscillates through the photogate. You
will be asked to enter the number of oscillations. The CBL will
measure the period of this motion and report the average.
Option four, PULSE, measures the time between two blocking
events. If you are using one photogate, the timer starts when the
photogate is first blocked, and it stops when the photogate is
blocked again. When two photogates are used, you can time from
the blocking of the first gate to the blocking of the second
gate.
CALCULATOR LISTS
When you choose the MOTION option in the MOTION TIMING menu,
pertinent data is stored in lists on the calculator. The
following summarizes the arrangement:
L1 - time
L2 - distance
L3 - velocity
L4 - acceleration
X.OVERVIEW OF EACH PROGRAM
A. The PHYSICS program will call the other programs depending
upon the options you choose. Each program is briefly described
below.
PHYSICS - This is the main program that controls the set up of
the probes and the experiment. Begin by running this program.
PHZCALIB - This calibration program provides three options
allowing you to: 1) to use a default calibration, 2) perform a
new calibration, and 3) manually enter the slope and intercept
for a known calibration. For specific help in performing a new
calibration, refer to the information sheet that came with each
sensor.
PHZCALS - This file contains the intercept and slope values for
each Vernier analog probe. You can edit this file with the
calibrations of your set of probes.
PHZGRAPH - This program performs various graphing functions.
PHZMICRO - This program is called when you select the Microphone
from the list of probes.
PHZMONIT - This program is called when you want to monitor the
readings from one or more channels.
PHZOPTIO - This program is used to select regions of data,
determine integrals, and set experiment triggering.
PHZTIMEG - This program produces graphs of active channels as a
function of time. If only one probe is active, a real time graph
can be displayed on the calculator as the data is collected. If
more than one channel is active, a real time graph will not be
available. You will have to wait until the data collection is
done in order to see the graphs.
PHZTRIGG - This program supports the trigger/prompt and trigger
data collection modes. Each time you press the [TRIGGER] button
data is stored in the CBL. In the trigger/prompt mode you will be
prompted for an independent variable. In the trigger mode, you
will not be prompted for a variable.
B. The TIMER program will call the other programs depending upon
the options you choose. Each program is briefly described below.
TIMER - This is the main program that calls the subprograms. Run
this program to begin.
TMGTSTAT - This program checks the status of the photogate and
reports whether the gate is blocked or unblocked. Move an object
slowly through the gate to see is the gate status changes between
blocked and unblocked.
TMMOTION - This program uses picket fences, bar tapes and
photogate/pulley systems to collect distance, velocity, and
acceleration data.
TMGATE - This program measures the time that a photogate or two
photogates are blocked.
TMPENDLM - This program determines the period of an object as it
oscillates through a photogate.
TMPULSE - This program measures the time elapsed as an object
travels between two photogates or the time as an object moves
through the same photogate twice.
XI. PROGRAM DESIGN NOTES
These programs have been written to support Texas Instruments and
Vernier probes with the CBL. We hope they help you perform a
variety of experiments with this exciting technology. Please feel
free to share these programs with other teachers and students.
Hopefully they have been written in such a way that you can
modify them for your particular application.
The programs were designed and written by Rick Sorensen and
Matthew Denton. Please contact us if you have any questions
concerning these programs or the use of our probes with the
programs.
March 27, 1998
Rick Sorensen (rsorensen@vernier.com)
Vernier Software
8565 S.W. Beaverton-Hillsdale Hwy.
Portland, OR 97225-2429
phone: (503) 297-5317
fax: (503) 297-1760
http:\\www.vernier.com
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