Last Update: September 1, 2008
Set-Up
The temperature probe should be connected to the calorimetry thermometer when you arrive. If it isn't, plug it into the connection labeled Bucket on the back of the thermometer. Connect the thermometer to a network jack using a standard ethernet cable. Attach the power cable and plug it in. Do not make any connections from the calorimetry thermometer to any other part of the bomb or solution calorimeter. For bomb calorimetry, you will be controlling the stirring motor and firing the bomb using the bomb's original equipment (Important! attempting to control the stirring motor for the bomb calorimeter using the calorimetry thermometer will trip the GFCI outlets and shut down the instrument). The only thing on the solution calorimeter that one could control would be the stirring motor, and that is just as easily turned on/off manually. Once all of the connections are made, turn on the thermometer and allow it to warm up for at least 20 minutes before attempting the first run. Be sure that you have found the special stylus for the touch screen before continuing (your finger will do, but please do not use a pen or pencil on the touch screen).
When the main menu appears, you will need to confirm various settings. First push the Operating Controls button and confirm that Method of Operation is set to Solution. If not, push it to toggle from Bomb to Solution. If you do this, you will have to restart the thermometer. This isn't entirely necessary, but it does remove some unnecessary features from the Main Menu and prevents mistakes. If you want to run in a more automated mode with the bomb calorimeter, you could set this toggle to Bomb.
Return to the Main Menu and select Communication Controls. Under Network Interface check that DHCP (Automatic setup) is On and that the Network Driver is On. If either of these was set incorrectly, press Restart Network. Once these are set correctly, push Network Status and scroll up on the screen to the line that reads "inet addr: 150.243.36.15" (the actual numbers may be slightly different). Copy down these numbers (the instruments IP address) for use later.
Operation
While this calorimetry thermometer has numerous features that will allow the operator essentially hands-off operation, you will, in general, not take advantage of them for pedagogical reasons. If your research requires some degree of automation, you are referred to the Parr 1672 Calorimetry Thermometer Operating Instruction Manual (copies of which are available in MG 1026). When running in the non-automated the bomb or solution calorimeter functions as it would have with a mercury thermometer or a Parr 1661 calorimetry thermometer (i. e., the operator initiates stirring, fires the bomb and injects the sample into the calorimeter). The main difference between the Parr 1661 and the Parr 6772 is that the 6772 will automatically record the temperature as a function of time and allow the data to be ported directly to a computer.
To collect data in the non-automated mode, return to the Main Menu and select Diagnostics. Select Data Logger and press Delete Data Log File, if you want to remove a previous operator's file. Set the Data Log Destination to Logfile Only. Under Select Data Log Items only TI should be selected (this should record the temperature, but you will get some extraneous information anyway). For Data Log Format, either Data Format (CSV) or Text Format will work, but the CSV (comma separated values) format makes it a little easier when it comes time to import your data into Excel. The last parameter to set is the Data Log Interval, which can be set however you please. It is advisable that after examine your data after each run and decide whether this rate is acceptable. Finally toggle the Data Logger to On. Note that once the data logging has been started, the temperature (and whatever else you chose to record) will be written to the log file until you turn data logging off. Therefore, it is advisable that you only start logging data just before beginning a run and turn it off as soon as possible after a run terminates.
To recover the data from the calorimetry thermometer, start a web browser on a computer interfaced to the network. In the browser's address line enter "ftp://root:rootroot@150.243.36.15/../flash/log/", omitting the parentheses, where the numbers will be replaced by the actual IP address for the thermometer that you recorded earlier. A list of the files on the thermometer in the log directory should appear. Double click on log.csv (if you saved the file as in CSV format). You will be asked what you want to do with this file, and perhaps which program you want to use to open it. The default is usually Excel, and that will be a good starting point. When the file opens the first column will contain the date and time (adjust the column width to view all of the cell's contents, if needed), while the second should be the temperature. The other columns do not contain any useful information. Save this file to your Y: drive or a personal data storage device. Once the data has been saved, close the browser. Note that you will want to insert a column between the time and the temperature data and use Excel's fill function to create a more useful time axis based on time interval that you selected.
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