BW May 2015

5/18: I swept and vacuumed in the labs. I scraped yellow foam off the floor in 405. I started to arrange tools on the bundling table and the round table. I found a place for one of the screwdrivers in a toolbox from the storage closet, and the Allen keys fit in holders that were in the toolbox and the storage closet.

I opened Secunia PSI on two computers to see if the programs were up to date, and on one it said 85% and on the other it said 97%. However, the PSI would not display the list of programs that were up to date or needed updating, so I clicked "Scan now." The program began to locate files, and it appeared that this activity would take a long time, so I left work with the computers running the PSI.

5/19: The first computer I checked was still running the PSI. It said it was "Preparing scan." Now I did not believe that it was going to complete the scan. It had been at work for more than 18 hours already. I closed the PSI and reopened it, but it still would not show a list of programs to be updated. After some Google searches, I found a website with directions for making the Secunia website a Trusted Site. After this change, the list of programs appeared and the PSI said they were all up to date.

May 26: I updated Adobe Reader and looked for other programs that needed updating. Java installs updates automatically every Sunday. We can run the NI Update Service to find updates for all National Instruments software. Instacal and TracerDAQ do not appear to have an update service. When I opened Instacal, there was a message giving me the choice to close the program or remove the DAQ from the list of boards because for some reason Instacal could not communicate with the DAQ. So in order for Instacal to keep running I had to remove the DAQ.

Later I wanted to run the hot plate in the heating box and collect temperature data with LabVIEW, but LabVIEW could not use the DAQ because I had removed it with Instacal. I opened Instacal again, but it could not even find the DAQ. After I unplugged the USB cable and reconnected it, Instacal found the DAQ and LabVIEW began to collect data, but the temperature measurements were obviously wrong. There had been no heating, so all four thermistors should have indicated room temperature, but instead one temperature gauge said 263 °C, another 60 °C, and the other two said NaN. May 27: I copied the LabVIEW program and added a function that would record the voltage data from the thermistors in a spreadsheet. I found that the voltages were varying as a tangent wave. Then I calculated the temperature from the voltage, and the final temperatures in the file matched the temperature indicators in LabVIEW. The NaN values occurred because when the voltage was negative, the formula for temperature required the natural logarithm of a negative number, which does not exist.

I also copied some temperature data files from tests during the spring semester and calculated the voltages from which the temperatures had been derived. They were much different from the voltages I had been seeing, since they always decreased as the temperature rose. At 23.3 °C, for instance, the voltage was 1.1 V, and at 75.8 °C the voltage was 0.316 V.

May 28: Brendan changed the DAQ configuration in Instacal to “8 Single Ended,” and LabVIEW gave accurate temperature measurements.