We’ve used Vernier probes and LoggerPro frequently in our classes for years, usually using a computer/LabPro interface to collect data. We of course always get good data, but the limiting factor is always the computer, as boot up/login time on our network could take anywhere from 5-10 minutes. Since we’ve got 40-minute periods on most days, this made it difficult to fit in labs as needed. This past year, one of our biology teachers ordered a class set of LabQuests, which we were able to borrow from time to time. The LabQuests made the data collection process much more seamless, and we were able to collect data much more efficiently in our 40- and 80-minute periods. We decided very early on that we wanted to order a dedicated chemistry set for next year.
Then the LabQuest 2 came out.
LabQuest vs. LabQuest 2
The original LabQuest boots up noticeably faster than the LabQuest 2. I’ve found that the LabQuest 2 takes at least 45 seconds to 1 minute, whereas the original Labquest is up in 10-15 seconds.
Both models have a rechargable battery. Even with heavy use both can last a full class day before they need to be recharged (when powered down during downtime).
The LabQuest 2 comes with significantly more screen real estate than the original LabQuest. (13 cm vs. 9 cm diagonal). Like a tablet, it has a horizontal and vertical orientation (turned off by default). Switching from one orientation to another is very clunky (1-2 seconds of blank screen when you turn it), and the vertical orientation doesn’t seem to add anything useful to the collection mode.
The touch screen has significantly improved in the new LabQuest 2. You can easily get by without a stylus. It is most responsive when navigating between tabs and menus, however when entering in text or numbers, it can be a little too sensitive.
The keyboard is annoying in both models, for different reasons. In the original LabQuest, even with a stylus, student had trouble typing due to the small screen space. With LabQuest 2, there’s plenty of room, the keys are relatively easy to hit, but at times too sensitive. The main keyboard would be improved if it included a period, comma, and basic symbols, rather than burying them 2 or 3 clicks deep (It took about 2 minutes for me to find the percent symbol, for instance). The placement of the space bar, also, is awkward. I suppose I’ve just become spoiled by the simplicity of iOS keyboards.
The LabQuest 2 has 3 analog ports (Channels 1-3) and two digital/sonic ports (DIG 1-2). The original Labquest has 4 analog ports, and two digital ports.
Both models have a USB and a mini-USB port. The Original LabQuest has an SD expansion slot, while the LabQuest 2 has a micro SD expansion slot.
Both models have a built-in microphone and ambient temperature sensor. The original LabQuest has a sound sensor. The LabQuest 2 has GPS, an accelerometer, and light sensor.
Both interfaces can connect directly to a computer via Micro USB port for added flexibility in data collection. Users can save data files and graphs to external flash drives. The LabQuest 2 stands out, however, because it has built-in WiFi. Its incredibly easy to get connected, and set up email. This allows users to print (to a wireless HP printer), email screenshots (.png), graphs (.pdf), LabQuest data files (.qmbl), and text files (.txt).
Students can also use any web device to connect to the LabQuest 2, either by scanning a QR code or entering a short URL into a browser. There, they can perform many of the same analysis as on the Qualitative Analysis iPad app, or simply watch live readings.
The Periodic Table app is similar in both models, but there is more data in the LabQuest 2 app. Both models have a stopwatch. In addition, the LabQuest 2 has an Audio Function Generator.
The added screenage on the LabQuest 2 and improved touch screen makes it much easier to collect and analyze data without connecting to a computer. For instance, we never had much success with managing the SpectroVis probe on the original LabQuest, and instead connected them directly to computers via USB.
Inspired by a recent Journal of Chemical Education article, I decided to add a spectrophotometry challenge as one possible lab challenge for my post-AP seniors.
Design and perform a colorimetry experiment to determine the percentage of cranberry juice in a cranberry-apple juice cocktail.
The paper suggests that apple juice absorbs around 392 nm, and cranberry around 520 nm. I collected an absorbance vs. wavelength full spectrum for several samples:
There is a single clear peak in the apple juice sample around 391 nm, which is consistent with the paper. This same peak is present in the Cran-Apple sample, so I assumed the other peak could be attributed to the “cranberry” juice. However, when I you look at the “Just Cranberry” (ingredients: cranberries, water) sample, there is also a peak at 392 nm, suggesting that the pigment present in apples are also present in cranberries (and in significant amounts). So using the “cranberry only” peak, I produced a calibration curve with diluted samples of Just Cranberry.
We can then use the linear(ish) relationship between absorbance and concentration to extrapolate the percent concentration of cranberry juice in the other samples
Though we’ve used the SpectroVis several times using this sort of protocol in several contexts, none of the three groups who did this challenge took this approach to answer the question, but they obtained very similar values (between 13-14% cranberry content).
All in all, the LabQuest 2 is a great improvement over the original LabQuest. Next year, I hope we’ll be able to explore the possibilities of the Connected Science System to enhance our lab experience.