1Scanner 2.0 - DraftThermocouple Scanning Using the Keithley 199 System DMM/ScannerMike Meier, December 31,2003 (draft)

Scanner is used with a Keithley 199 DMM/Scanner to record temperature as a function of time fromup to eight inputs. The data are plotted during the data collection procedure and saved as ASCII textor comma-separated variables files format. The data file can be opened again, plotted, and printed.Several common thermocouple types are supported and if desired one can record voltage readingsinstead of temperature.

Scanner was designed to be used in a widely used materials science laboratory teaching experimentwhere samples of molten Pb-Sn, Bi-Sn or similar alloys are cooled. During cooling, deviations fromthe normal cooling rates indicate the start, progress, and end of solidification and other phasetransformations. In most applications only two or three cooling curves are collected simultaneously,but it is capable of recording up to eight cooling curves.

Scanner will also work without a Keithley DMM/Scanner, but without its data collectioncapabilities. It can collect data in a demonstration mode, where crude cooling curves aregenerated by the program. This can be very helpful when learning how this program works or todemonstrate the differences in the different types of thermocouples. In demonstration mode,Scanner can still read and display existing data files.

FeaturesThe primary features of Scanner are: Up to eight cooling curves can be recorded simultaneously Data is plotted as it is collected, and the graph is automatically re-scaled to show all of the

data. The results can be saved as standard ASCII (*.txt) and comma-separated variable (*.csv)

files. Both file formats can be opened again, display, printed, etc. The data collection procedures can be saved and reused. A one-page report including all data collection variables and the graph can be printed.

In addition, you can zoom in (drag with the left mouse button) and out (click the right mouse button)on the graph. If you double-click the graph Scanner will hide the controls and resize the graph sothat is completely fills the form.

CopyrightThis program and its documentation are copyrighted by Mike Meier, December 31, 2003. Allrights reserved.

DisclaimerThis software and manual are provided as is and without warranties as to performance. Whileconsiderable effort have been made to ensure its accuracy the user must verify that it meets therequirements for all intended applications.

2DistributionEducational Users: Writing Scanner provided me with an opportunity to develop myDelphi/Windows programming abilities and to make something I could give to the students in mylaboratory courses. I am happy to offer it for free to non-profit educational users, including students,staff and faculty.

Commercial Users: Private and commercial users pay $20 for each copy of this program. Thisprogram represents about 2 months of midnight engineering, including many early mornings, andan investment in a number of programming tools and many Windows and Delphi-programmingbooks.

RegistrationPlease register this software. To register simply fill out the registration form and mail or email itto me at the address given below. Your registration will give me a better idea of who is using thisprogram. I will not share your personal information with anyone.

FilesThe following files are included with this program:1. Scanner 2.0.exe The program2. Scanner 2.0.pdf Documentation (This document)3. Registration Form.pdf Registration form4. *.csv Sample data files

InstallationTo install Scanner simply copy the program and data files to a directory of your choice and copy theini file to the Windows directory. Create a shortcut and put it in the Materials Science section of theprograms branch of your START menu.

FeedbackI am interested in hearing from people, particularly students and instructors, who use this program.Please email me at: mlmeier@sbcglobal.net or mail me at:

Mike Meier515 K StreetDavis, CA 95616USAemail: mlmeier@sbcglobal.net

3Figure 1 Screen shot of Scanner 2.0 showing two open data files and a data collection project.

Using the ProgramScanner is very easy to use. The major steps involved are:

1. Connect the computer, DMM/scanner and thermocouples and turn everything on.2. Start the program.3. Create a new project or open an existing project.4. Edit the project, such as data file name, thermocouple types, number of channels, etc.5. Start the data collection.6. Monitor the data collection using the graph and status panels.7. Stop the data collection when done.8. Print a report.

The Keithley 199 System DMM/Scanner is a ...

If the Keithley DMM/Scanner is not present...

Description of FeaturesScanner uses Windows MDI (multiple-document interface) feature to let you work with more thanone project at a time. It can have up to 50 projects open at one time and options under the File menualso let you save, close and print projects and open and display data files. Figure 1 shows a screen

4Scanner 2.0 Scan Project Definition Form

shot of Scanner which has two data files and a new dat collection project open. These forms canbe moved, resized, tiles, cascaded, etc. In addition, the background color can be changed.

ScanningScanner will scan channel 1 through n channels at user defined time intervals. (A maximum of 8channels can be scanned using the Keithley DMM.) During scanning the data is plotted

Scan Procedures (Projects)Scanner can be used to create, save and reuse scan procedures. Scan procedures include thefollowing:

1. Project title and other descriptive text 2. Data file name and format3. DMM settings function, range and resolution4. Scan settings interval and duration5. Sensor options type of thermocouple and a name for each channel6. Graph options Graph title and descriptive text, initial scaling (Graphs will be automatically re-

scaled to fit the data if necessary.)

GraphsScanner uses two types of time-temperature graphs. During scanning a simple time-temperaturegraph showing all channels is used. By clicking the check boxes in the legend/status panel one canhide or show selected channels. Data can be reloaded and display in two types of graphs, the onejust described and the other plots dT/dt on the second y axis and displays data for only one channelat a time. Other features of these graphs are:

5Autoscaling The graph will automatically rescale itself whenever the time or temperature exceedsthe range and domain of the graph. This feature is disabled when the user has zoomed in.

Zoom In Hold down the left mouse button while dragging the mouse across the plotting area.Multiple zooms, down to 1 degree - 1 second scaling, is supported.

Zoom Out Right-click the plotting area.

Hide Panel Double-click the graph to hide or show the legend/status panel.

Cursor Position When the mouse is in the plotting area the cursor position will be displayed inthe graph forms status bar at the bottom of the form.

Multiple Graphs Many graphs showing previously saved data can be displayed at the same time.Only one of these can be the graph associated with the scan procedure.

Demo ModeScanner can be run in demonstration mode. During demonstration mode all features of Scanner areavailable except actually communicating with the Keithley DMM. Instead, a crude simulation ofcooling curves is generated. One can switch in and out of demonstration mode at any time exceptwhen a scan is in progress and when Scanner was not able to initialize the GPIB interface and theDMM.

PrintingAn attractive and informative printout of any graph can be printed. The printout includes the scanand channel settings, units, user comments, dates and times and other details fo the scan plus thegraph of the data as it is currently displayed. A sample printout can be found at the end of thisdocument.

Data FilesData files are created when scanning starts. Data are saved as they are received. All data filesinclude a header section which contains all critical setting used during the scan, the data itself, anda footer that notes the status of Scanner at the end of the scan. Two file formats are supported,standard ASCII *.txt files and ASCII comma-separated-variable files (*.CSV). Both file formatsare supported by many other computer programs. Double-clicking the *.CSV file, for example, willlaunch your spreadsheet program and import the data. Both file formats can also be opened usingScanner.

LimitationsMaximum Scans Scanner can store data for up to 8192 readings.

Printing Landscape orientation is not supported.

Known ProblemsResizing the Forms The graph and status panel in the graph forms may not resize properly,especially when making the form smaller. If you resize the form again, making it slightly larger,everything should be OK.

6Default Directories Different default directories will be used by the save and open dialogs and thebrowse button. I hope this does not cause any problems. Ill fix it soon. Meanwhile, pay attentionto where you save your files.

RecommendationsDemonstration Mode Use the demonstration mode to learn how to use the program before startingreal data collection.

Scanner Settings The computer is fast, but the Keithley DMM is a bit slow. While this may causethe program to pause briefly while reading or writing to the DMM, it can be a real problem whenperforming the scan. The system must be able to scan all channels and still leave time for the systemand the user to accomplish other tasks. To keep the ratio of scan time to free time at a reasonablelevel you have to balance the scan interval (time between scans), the number of channels scanned,and the conversion resolution (4-digit or 5-digit). Scanning at 4-digit resolution is about 8times faster than scanning at 5-digit resolution, so the recommended resolution is 4-digits formost cases where the scan interval is less than 5 seconds.

Other Tasks Scanning will continue even when the program is minimized, the computer is locked,etc., but the timer interrupt used by Scanner does not have a very high priority in the system.Certain tasks, such as disk accesses and even dragging a form, have higher priorities. As much aspossible, avoid starting up other programs or doing other things that may keep the system busy longenough to cause Scanner miss scans. To help in this regard Scanner disables most functions thatcould slow the system down.

Scanner 2.0Temperature Scanning for the Keithley 199 DMM/ScannerVersion: 1.99, February 5, 2002

ProjectName: gr1-0-30-11-12-03Description: Temperature Scanning for the Keithley 199 DMM/ScannerOwner: K Street Technology CenterFile Name: gr1-0&30-11-12-03.csv

Sensor Options1: Type K Thermocouple, 0% Bismuth2: Type K Thermocouple, 30% Bismuth3: This channel not used in this scan.4: This channel not used in this scan.

5: This channel not used in this scan.6: This channel not used in this scan.7: This channel not used in this scan.8: This channel not used in this scan.

DMM/Scanner ParametersDMM Status String: 1990204000022010000001010000000001Function: DC VoltsRange: 300 mVResolution: 4 digits

Sampling ParametersPeriod: 1 secondChannels Scanned: 1 through 2Start Time: 11/12/03, 15:01:11End Time: 11/12/03, 15:13:01Duration: 0:11:49 (710.0 s)Samples: 711

Comments

Printed on Friday, January, 2, 2004, 7:44:48 pm

0 73 146 219 292 365 438 511 584 657 730Time, seconds

K Street Technology CenterTemperature Scanning for the Keithley 199 DMM/Scanner

Scanner 2.0

0

50

100

150

200

250

300

Tem

pera

ture

, C

Legend0% Bismuth

30% Bismuth