VERNIER SOFTWARE CHEMISTRY AND BIOLOGY PROBES WITH THE TI CBL AND TI-92 This document describes the use of a group of programs that supports Vernier Software chemistry and biology probes for use with a TI-92 calculator and the TI Calculator-Based Laboratory (CBL) System. The following Vernier probes are directly supported: Vernier Direct-Connect Temperature Probe, pH, Pressure Sensor, Colorimeter, Voltage Measurement leads, Conductivity Probe, Dissolved Oxygen Sensor, Barometer, Relative Humidity Sensor, Biology Gas Pressure Sensor, Respiration Monitor Belt, EKG, Heart Rate Monitor, Standard Temperature Probe, Quick Response Temperature Probe, and Thermocouple. The Texas Instruments Temperature Probe, Voltage Probe, and Light Probe are also supported. The programs appear on this disk in a group file. You can identify the TI-92 groups because they end in "92g" while program files have the "92p" extensions. The extensions on the filenames appear only on the computer and do not appear when you see the program names on the calculator. SENDING GROUP FILES The CHEM-BIO.92g file is eleven programs that have been grouped together. The easiest method of loading all eleven programs on to your calculator is to transfer the CHEM-BIO.92g group file through the Send Group Files option in the TI-Graph Link program. (The "TI- Graph Link Guidebook" describes the process of sending group files.) UNGROUPING THE FILES You may prefer to "ungroup" the CHEM-BIO.92g 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 eleven programs available: CHEMBIO.92p, CMBCALIB.92p, CMBCALS.92p, CMBDERIV.92p, CMBEKG.92P, CMBGRAPH.92p, CMBHEART.92p, CMBMONIT.92p, CMBTIMEG.92p, CMBTRIGG.92p, and CMBTRIGP.92p. Refer to the "TI-Graph Link Guidebook" for help in working with group files. PROTECTED PROGRAM FILES All the programs in this file have been locked so that they cannot be accidentally edited on the calculator. This feature prevents students from editing a program. The easiest way to edit protected files is with the TI-Graph Link program. However, they can be edited on the calculator, but they must first be unlocked. The TI-92 manual describes this process. MEMORY REQUIREMENTS This entire set of programs will require about one third of the available memory on the TI-92. If you run into memory errors, it may be necessary to delete one or more programs from the calculator. If there are certain data collection modes you are not using, e.g. trigger, you can delete programs associated with these modes. (You will find a description of each program later in this document.) You may also want to consider deleting the CMBHEART and CMBEKG programs if you are not using the Heart Rate Monitor or EKG sensor. Refer to the calculator manual for help with deleting files. PERFORMING EXPERIMENTS WITH THE CHEMISTRY/BIOLOGY PROGRAM The CHEM-BIO programs function together to provide a wide range of options as you create and run experiments. After all eleven programs have been loaded, run the CHEMBIO.92p program. (Remember, the name of the program will appear as "CHEMBIO" on the calculator.) The CHEMBIO.92p program uses a series of menus to set up different types of experiments with a combination of the above probes. The following general description applies to the use of these programs on the TI-92 calculator. For specific help in executing programs on the calculator, refer to the TI-92 manual. To begin, turn on the CBL and link the TI-92 and CBL with the black cord that came with the calculator. Make sure that the plugs are firmly pushed into the TI-LINK port on the top left hand corner of the calculator and the bottom edge of the CBL. Connect the appropriate probes starting with Channel 1 (CH1) found on the top edge of the CBL. The programs mentioned above function together to provide a wide range of options as you set up and run experiments. After all eleven programs have been loaded, run the CHEMBIO.92p program. This is done by first pressing the [2nd] [VAR-LINK] keys. A list of all the files and directories on the calculator will appear in a pop-up screen. Use the cursor pad to locate the MAIN directory. Scroll through this directory to find the CHEMBIO program. Press [ENTER] to return to the Home screen. The Entry Line will display "chembio(". Press the right parenthesis ")" followed by the [ENTER] key. After an introductory screen, the following MAIN MENU will appear: ***MAIN MENU*** 1:SET UP PROBES 2:COLLECT DATA 3:VIEW GRAPH 4:VIEW DATA 5:RETRIEVE DATA 6:QUIT The first option, SET UP PROBES, is used to 1) enter the number of active probes, 2) choose a probe, 3) enter the CBL channel number for the probe, and 4) choose the method of calibrating Vernier probes. 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. Correct any problems before continuing. The SET UP PROBES option will produce the following menu: SELECT PROBE 1:TEMPERATURE 2:PH 3:PRESSURE 4:COLORIMETER 5:VOLTAGE 6:CONDUCTIVITY 7:MORE PROBES These options represent the following Vernier Software probes: Vernier Direct-Connect Temperature Probe, pH System, Pressure Sensor, Colorimeter, Voltage Measurement Leads, and Conductivity Probe. Option 1:TEMPERATURE and option 5:VOLTAGE can be used for the TI Temperature Probe and TI Voltage Probe that come with the CBL. If you select option 7: MORE PROBES, you will get another list of probes. SELECT PROBE 1:D.OXYGEN 2:BAROMETER 3:LIGHT 4:REL HUMID 5:BIO PRESSURE 6:HEART RATE 7:MORE PROBES The first six options represent the following Vernier probes: Dissolved Oxygen Sensor, Barometer, Light Sensor, Relative Humidity, Biology Gas Pressure Sensor, and Heart Rate Monitor. Option 3:LIGHT can be used for the TI Light Probe. If you select option 7: MORE PROBES, you will get another list of probes. SELECT PROBE 1:VERNR STD TEMP 2:VERNR QIK TEMP 3:THERMOCOUPLE 4:RESPIR. BELT 5:EKG 6:CUSTOM 7:RETURN These options represent the following Vernier probes: Standard Temperature Probe and Extra Long Temperature Probe, Quick-Response Temperature Probe, Thermocouple, Respiration Monitor Belt, and EKG Sensor. The sixth option, CUSTOM, can be used for a custom probe. The seventh option, RETURN, returns you to the first list of probes. The above screen(s) will appear up to three times depending upon the number of probes you entered, except in the case of the Heart Rate Monitor and EKG. (These two options run separate programs described later.) After you select a probe, you will be asked to enter the channel number for that probe. This program assumes that the probes are connected to the lowest available channels. NOTE: It is important to mention another consideration when setting up an experiment with some probes. Certain combinations of probes will interact with each other if they are put in the same solution and connected to the same CBL. Do not use combinations of the following probes on the same CBL and in the same solution: Dissolved Oxygen Probe and Conductivity Probe with each other or in combination with the pH System or Vernier Direct-Connect Temperature Probe. After you enter the channel number for a Vernier probe, you will be presented with a CALIBRATION menu except in the case of the Colorimeter. (The Colorimeter should be calibrated prior to each use. Therefore, when you select that probe, you will be sent to the PERFORM NEW calibration option described below.) The following is the CALIBRATION menu for the other Vernier probes: **CALIBRATION** 1:USE STORED 2:PERFORM NEW 3:MANUAL ENTRY 4:POLARIZE PROBE Option 1, USE STORED, allows you to load calibration values for the various Vernier probes from a calculator file. These are "generic" calibrations 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 CMBCALS.92p program contains these slope and intercept values. It is possible to edit this program and enter the slope and intercept values for your probes. Option 2, PERFORM NEW, is used to perform a new calibration. To understand the calibration process, it is helpful to understand the operation of Vernier probes. During their operation, the probes produce a voltage that is linearly dependent upon a quantity being measured. For example, the temperature probe produces a voltage that varies linearly with the surrounding temperature. During the calibration process, the computer establishes the linear relationship between voltage and temperature. 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 temperature probe. The same general procedure can apply to most of our probes. Begin by placing the temperature probe in an ice bath. As the probe is swirled in the ice water, monitor the CBL to see the voltage produced by the probe. When the voltage stabilizes, press the [TRIGGER] button on the CBL. You are then prompted to enter the reference value, "0" (degrees Celsius). Place the temperature probe in a second reference such as boiling water or room temperature water. The voltage is again monitored and the [TRIGGER] button is pressed when the voltage stabilizes. Enter the second reference value measured with a thermometer. A slope and intercept for the linear calibration curve are then displayed on the calculator and automatically 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 help with a particular probe, refer to the information sheet for that probe. Option 3, MANUAL ENTRY, in the CALIBRATION 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 temperature 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. Some probes such as pH and Colorimeter do not hold their calibrations and may need to be recalibrated prior to their use. Option 4, POLARIZE PROBE, is used to polarize the Dissolved Oxygen Probe. When selected, a power-up command is sent to the CBL. The polarizing process takes thirty minutes and is necessary for proper operation of the probe. 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 and/or CBL. The purpose of this option is to view data at 1.0 second intervals. No data are stored. For most probe combinations, each active channel will be displayed on the calculator. However, if there is more than one active probe and the probe combination contains a pH System, Conductivity Probe, or Dissolved Oxygen Probe, you will only be allowed to view a single channel at a time and you will be prompted with the following menu to choose a channel: SELECT A CHANNEL 1:CH 1 2:CH 2 3:CH 3 4:QUIT After selecting a channel, the calculator will display a reading from that channel on the calculator except in the case of a Dissolved Oxygen Probe or pH system. In the case of these probes, you will have to monitor their readings on the CBL display. You will be presented with this message: MONITOR CBL DISPLAY. USE THE [CH VIEW] BUTTON TO SELECT CHANNEL NUMBER X PRESS [TRIGGER] BUTTON TO QUIT. The CBL will be put in the "READY" mode and it will display the reading from channel 1. 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 you are done monitoring the channels on the CBL, press the [TRIGGER] button on the CBL and select the QUIT option on the calculator. If you are monitoring the channels on the calculator screen, press the [+] key on the calculator to quit. The TIME GRAPH option from the DATA COLLECTION menu is used to graph up to three channels as a function of time. The design of this option was based on the assumption that most chemistry and biology users would want a real-time or live display as data are being collected. In most cases this type of graph is possible but in some experiments a live display will not be available. A live display will be produced for either of the following situations: 1) Only one probe is active and the time between samples is less than 270 s. 2) When more than one probe of the same type is active; the sample time is greater than 1.00 s for two probes, or greater than 1.25 s for three probes; and the time between samples is less than 270 s. Data will not be displayed live in any of the following arrangements: 1) Two or more different probes are being used. 2) The sample time is less than 1.00 s for two probes or 1.25 s for three probes. 3) The sample time is greater than 270 s. After you select the TIME GRAPH option, you will be prompted to enter the time between samples which is entered in seconds. If you want a live display, you must take into account the above criteria and enter an appropriate number. If you anticipate the data to be collected without a live display, the time between samples can be in the range of 0.000264 to 0.2 s or 0.25 to 16000 s. (If you have three active probes, the minimum sample time is 0.000364 s.) After the sample time is entered, you will be prompted to enter the number of data points. (The maximum number for the TI-92 is 99.) The CBL will then be set up to collect data in either live or non-live display as described above. In most experiments involving a time graph, data will be automatically sent from the CBL to the calculator. However, if the experiment is too long, the calculator will automatically power down (APD) and data will not be transferred to the calculator. This will happen in either of the following situations: 1) The time between samples is greater than 270 seconds. 2) Two or more different probes are being used and the total experiment is longer than 270 s. In either case you will be prompted with a message saying that you will have to choose the RETRIEVE DATA option at the MAIN MENU at the end of the experiment. After each experiment is run, the data is stored in the data CBLDATA on the calculator. The column numbers are displayed on the calculator screen after data collection. In general the independent variable is stored in c1, channel 1 is c2, channel 2 in c3, etc. The TRIGGER/PROMPT option 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. For example, you could use a Pressure Sensor to monitor the pressure of a gas enclosed in a syringe as the volume changes. When the [TRIGGER] button on the CBL is pressed, the CBL measures the gas pressure and you will be prompted to enter the volume of the gas in the syringe. The independent data is stored in co1umn c1 of the data CBLDATA and dependent data is stored in c2 through c4 depending upon the number of active probes. Each time you press the [TRIGGER] button, you will get the following screen: TRIGGER 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 allows the user to manually collect one sample at a time when the [TRIGGER] button on the CBL is pressed. Each time you press the [TRIGGER] button, you will get the following screen: TRIGGER 1:MORE DATA 2:STOP 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, data collection will stop and, if you have two active channels, a graph will be displayed. (The default graph in this case plots c1 as the independent variable and c2 as the dependent variable.) 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. In either TRIGGER/PROMPT or TRIGGER you can monitor each active channel during data collection 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 in the Main Menu, VIEW GRAPH, allows you to review previous 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 "ZoomData" option to provide automatic scaling of axes. You may prefer to quit the program to set your own scaling. The fourth option, VIEW DATA, exits you from the program so you can view the data. The fifth option on the MAIN MENU, RETRIEVE DATA, is used after long-term data are collected without a live display. Before you select this option, be sure the CBL is done collecting data. (The word "DONE" should appear in the CBL display.) The sixth option, QUIT, in the MAIN MENU will exit you from the program and return you to the prgmIO screen. Press the [F5] key to return to the home screen. USING THE VERNIER HEART RATE MONITOR WITH THE CBL AND TI-92 OVERVIEW The Vernier Software Heart Rate Monitor operates by monitoring the light level transmitted through the skin. A clip is attached to the ear lobe. One half of the clip contains an incandescent light bulb and the other half measures the amount of transmitted light. Since the intensity of the light is a function of the amount of blood in the ear, the output of the Heart Rate Monitor varies throughout the heart beat. When the light intensity data are collected as a function of time, a graph of intensity vs. time produces a periodic pattern. The pattern can be analyzed to determine the heart rate. The following material briefly describes the CMBHEART.92p program and its use with the Heart Rate Monitor, TI-92 calculator, and the TI Calculator-Based Laboratory (CBL) System. The primary uses of the program are 1) to collect and display data produced by the Heart Rate Monitor 2) to calculate the heart rate in beats/minute and 3) store heart rate values in a list and graph them vs. time. This program can be run by itself or it will be run when you choose the Heart Rate Monitor from the SET UP PROBE option in the MAIN MENU of the CHEMBIO program. GENERAL DESCRIPTION OF THE PROGRAM To begin, connect the Heart Rate Monitor to channel 1 on the CBL. Attach the clip to the ear lobe, finger tip, or to the web of skin between the index finger and thumb. Run the CMBHEART.92p program. (Note: the name of the program will appear as "CMBHEART" on the calculator). After introductory screens, the following main menu will appear. HEART RATE MENU 1:COLLECT DATA 2:VIEW LAST GRAPH 3:VIEW BPM GRAPH 4:RETURN To begin data collection, select option 1:COLLECT DATA. Once selected the screen on the calculator will enter split screen mode. An graph will be displayed on the screen. When data are retrieved from the CBL, time will be stored in column c1 of the data CBLDATA and voltage which is proportional to light level will be stored in list c2. The data collected in c1 and c2 is used to draw a waveform which is displayed along the graph on the screen. The calculated heart rate is displayed in beats per minute (BPM) on the top line of the screen. The beats per minute for each sample is stored in c3. If the CBL and heart rate monitor are unable to calculate the heart rate, a message saying "COLLECTING DATA PLEASE REMAIN STILL" will be displayed in the lower half of the screen. If the calculator continues to display this message, you may need to move the earclip around until you find a spot that gives you a better reading. To stop data collection and return to the main menu, press [ENTER] on the calculator. The second option in the main menu, 2:VIEW LAST GRAPH, displays a graph of the last data segment collected along with the calculated heart rate. This option is helpful when it is necessary to take a close look at the waveform or just to review what the heart rate was before data collection was stopped. To quit from this selection and return to the main menu, press [ENTER] on the calculator. The 3:VIEW BPM GRAPH option takes the list of calculated heart rates (in BPM) stored in c3 and plots them vs. time. The length of time between samples is estimated to be 15 seconds. To read the points plotted on the graph press the right arrow direction key located at the top right hand corner of the calculator. This option is very useful if you are performing an experiment which involves calculating an individuals recovery time or the effect of miscellaneous stimuli on heart rate. To quit from this selection and return to the main menu, press [ENTER] on the calculator. USING THE VERNIER EKG SENSOR WITH THE CBL AND TI-92 OVERVIEW The following material briefly describes the CMBEKG.92p program and its use with the EKG Sensor, TI-92 calculator, and the TI Calculator-Based Laboratory (CBL) System. The primary uses of the program are 1) to collect and display data produced by the EKG Sensor 2) graph the EKG data vs. time and allow the user to trace the data points for analysis of the EKG waveforms. This program can be run by itself or it will be run when you choose the EKG Sensor from the SET UP PROBE option in the MAIN MENU of the CHEMBIO program. GENERAL DESCRIPTION OF THE PROGRAM To begin, connect the EKG Sensor to channel 1 on the CBL. Place the electrode tabs along the subject's arms or legs as described in the EKG manual. Connect the three sensor leads to the electrode tabs. Run the CMBEKG.92p program or choose EKG from the list of probes. The following main menu will appear. CHEM-BIO EKG 1:COLLECT DATA 2:VIEW GRAPH 3:RETURN To begin data collection, select option 1:COLLECT DATA. Once selected the screen on the calculator will clear. The program will collect three seconds of EKG data. When data has been collected, a graph will be displayed and time will be stored in column c1 of the data CBLDATA and voltage stored in c2. To collect more data, press ENTER and select YES from the REPEAT menu. To stop data collection and return to the MAIN MENU, select NO from the REPEAT menu. The second option in the MAIN MENU, 2:VIEW GRAPH, displays a graph of the last data segment collected. This option is helpful when it is necessary to take a close look at the graph. To quit from this selection and return to the MAIN MENU, press [ENTER] on the calculator. The last option 3:RETURN will exit the program if you are running it by itself, or return you to the CHEMBIO MAIN MENU. POSSIBLE ACTIVITIES USING VERNIER CHEMISTRY AND BIOLOGY SENSORS WITH THE CHEMBIO PROGRAM 1) Use a Biology Gas Pressure Sensor and plastic tubing to measure the rate of transpiration in various plant specimens. Test how various physical phenomena such as wind, heat, light, and humidity affect the plant's rate of transpiration. 2) Use the Dissolved Oxygen Probe to measure D.O. levels in a stream or lake. Perform a 5-day BOD test using a collected water sample and the dissolved oxygen probe. Test how light and temperature affect an aquatic plant's ability to photosynthesize. 3) Determine the TDS (total dissolved solids) in a stream or lake using the Conductivity Probe. Measure the conductivity of a water sample in the field or in the lab. Determine the rate of diffusion of an ionic compound through a semi-permeable membrane by measuring the change in conductivity over time inside a section of dialysis tubing. 4) Test how possible stimulants affect an individual's heart rate using the Heart Rate Monitor. Determine if there is a relationship between body size and heart rate. 5) Compare the resting heart rates for different groups of people. For example, compare various groups of athletes, different age groups or sexes. 6) Monitor the heart rate as individuals recover after exercise. Do cross country runners return to a normal heart rate faster than baseball players? 7) Use a temperature probe to investigate endothermic and exothermic reactions. 8) Study the relationship between the pressure of a gas and its volume. 9) Use Beer's Law to determine the concentration of an unknown solution with a Colorimeter. 10) Determine the freezing point of water by graphing temperature as a function of time as it is cooled. 11) Determine the molarity of an unknown acid by performing a volumetric titration. 12) Use the Monitor Input mode for data collection to allow the pH System to function as a pH meter. Determine the acidity of various household substances such as milk, vinegar, soft drink, ammonia, etc. OVERVIEW OF EACH PROGRAM The CHEMBIO.92p program will call the other programs depending upon the options you choose. Each program is briefly described below. CHEMBIO.92p - This is the main program that controls the set up of the probes and the experiment. Begin by running this program. CMBCALS.92p - This file contains Vernier Software slope and intercept calibration values for the various probes. These values will give you reasonable data but you may prefer to calibrate each sensor individually. Once you have calibrated a specific probe, you may want to replace the Vernier calibration values in this file with your new values. This file can be edited to contain the new values. When you select the USE STORED calibration option, your values will then be loaded. Text that is used on the graphs is also contained in this program. CMBCALIB.92p - This calibration program provides three options allowing you to: 1) perform a new calibration, 2) manually enter the slope and intercept for a known calibration, or 3) to use a default calibration (see CMBCALS.92p). For specific help in performing a new calibration, refer to the information sheet that came with each sensor. CMBDERIV.92p - This program is used to view graphs of the first and second derivative of pH-volume data collected in acid-base titration experiments. It assumes that the independent variable, volume, is in list L1 and the dependent variable, pH, is in L2. When the program is run, the first derivative (delta pH/delta volume) is stored in L4 with the corresponding volume in L3. The second derivative (delta^2 pH/delta volume^2) is stored in L6 with the corresponding volume in L5. To take the derivatives, exit the CHEMBIO data-collection program and run the CMBDERIV program. The program will create three graphs; 1) pH vs. volume, 2) the first derivative vs. volume, and 3) the second derivative vs. volume. CMBEKG.92p - This program is run when you choose the EKG sensor from the list of probes presented during the probe set up. A complete description of the program appears below. CMBGRAPH.92p - The CMBGRAPH program contains graphing routines that are used in presenting graphs. CMBHEART.92p - This program is run when you choose the Heart Rate Monitor from the list of probes presented during the probe set up. A complete description of the program appears below. CMBMONIT.92p - This program allows you to monitor any or all of the three analog channels. Data will be displayed on either the calculator or CBL depending upon the combination of probes. CMBTIMEG.92p - This program produces graphs of active channels as a function of time. Live and non-live displays are produced depending upon the combination of probes and length of experiment. CMBTRIGP.92p - This program will allow you to collect data such as Boyle's law data that may not be time dependent. The program will prompt you to input an independent variable such as volume. The CBL will then measure a dependent variable such as pressure. CMBTRIGG.92p - This program uses the [TRIGGER] button on the CBL to collect data from each active channel. Each time you press the [TRIGGER] button, data are stored in the CBL. At the end of the experiment the data are retrieved from the CBL and stored in lists on the calculator. 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 program with other teachers and students. Hopefully they have been written in such a way that you can modify them for your particular application. The CMBHEART and CMBEKG programs were designed by Scott Holman and written by Matthew Denton. The remainder of the CHEM-BIO programs were written by Matthew Denton and Rick Sorensen. The programs were designed by Rick Sorensen, Dan Holmquist, Scott Holman, and Matthew Denton. Please contact us if you have any questions concerning these programs or the use of our probes with the programs. August 8, 1996 Rick Sorensen (rsorensen@vernier.com) Dan Holmquist Scott Holman (sholman@vernier.com) Matthew Denton Vernier Software 8565 S.W. Beaverton-Hillsdale Hwy. Portland, OR 97225-2429 phone (503) 297-5317 fax (503) 297-1760