STEM For Less
There’re few things that stir fear in the hearts of district purchasing managers more than buying classroom sets of STEM sensors and screens or software to collect and analyze the results. At several thousand dollars per room, their time might be nearing its end.
That’s because Vernier, a major supplier of STEM equipment, has an inexpensive alternative that relies on an iPad tablet for the smarts. The Go Wireless Temp sensor is not only inexpensive at $75 but takes just a few seconds to connect and start collecting data.
The actual temperature sensor has a 4.5-inch stainless steel probe that works well with a beaker of ice or boiling water, measuring how hot the school’s vents are or even doing a survey of the class’s body temperature. It can be dunked underwater at a depth of three-feet for up to 30 minutes and even stands up to acids or bases for limited periods.
Inside the Go Wireless Temp probe is a calibrated temperature sensor, a battery and a low-power Bluetooth radio. The probe’s battery can be charged with the included USB cable that fits over the device’s base or eight at a time with Vernier’s $40 Charging station.
Able to record temperature from -40 to 125 degrees Centigrade, the probe’s Bluetooth radio connected on the first try with an iPad Mini in a matter of seconds. It works with all recent iPads but not early models that don’t have Bluetooth.
It has a response time of 20-seconds, collects temperature data in .0625-degree increments and has a rated accuracy of 0.5 degrees C. The probe’s output agreed to within a tenth of a degree with three thermometers and should be accurate enough for high-school students to use to build their own calorimeters in a chemistry or physics class while remaining easy enough for first graders to use to explore temperature.
The probe has a wireless range of about 8-feet but I suspect that it will almost always be within an arm’s reach of the tablet it’s connected to. The good news is that adjacent probes that are connected to iPads don’t interfere with each other.
Its 100 milli-amp hour battery pack is rated to last a year of regular use and can be swapped with a new one in a couple of minutes; replacement batteries cost $7. The Go Wireless Temp probe ran for more than 3.5 days of continuous use on a charge, meaning that it will likely only require a weekly charge even if it’s used for a couple of periods of science class daily.
The temperature probe was able to maintain contact for more than 36-hours without interruption, although when it does lose contact with the pad you need to manually select the sensor from the software’s list and manually reconnect. On the downside, all the previous data is lost.
The device’s LED glows blue when it is charging, while a smaller light blinks red when it’s ready to connect and green when it’s connected. On the downside, it’s hard to see the flashing light in anything but a darkened room.
While using the free Go Wireless Temp iPad data acquisition app is a good start, there’s nothing for Android slates or PCs, but the company will soon have an interface for its LabQuest handheld devices. The software shows the current temperature on the left side of the screen in a bar graph format while displaying a time-based fever plot of the data on the right. While the app can run in vertical or horizontal mode, but you can’t adjust the data’s scale, presentation or even change the color of the graph. You can change the probe’s temperature units, name and see the charge level.
Using the $4.99 the Vernier Graphical Analysis app is a big step up and should be included with the probe in a school package. It not only lets you show up to three graphs at once, mark predictions and resize the graph, but the software lets you add captions and the software has curve fitting routines.
At any point, you can export the data in a variety of formats for inclusion in a lab report. The basic app only lets you email a comma separated data file or manually take a screen shot of the graph.
When using the Go Wireless Temp sensor, the first thing you should do is set the iPad not to dim or shut off the screen by turning off the unit’s Auto Lock feature in the Settings section. Even when the screen is off, it still receives, tabulates and graphs the readings, but it’s better to not have to continually wake the pad up.
While the system’s battery comes with a 1-year warranty, the probe itself is covered for 5-years. At $75, it is a bargain, although schools will probably buy them in the classroom eight-pack with a charging station for $550, which brings the price down to $68.75 per unit.
The beauty of Go Wireless is that it can help to teach science by doing science. A great start, the next step is the arrival of a full line of compatible sensors, including ones for everything from acceleration and pH to measuring electrical properties and light. When that happens, it will truly be ready for school.
$75/Teacher Pack with 8 probes and charging station: $550
+ Inexpensive temperature monitor
+ Self-contained battery
+ Quick set up
+ Free iPad interface
+ 5-year warranty
+ Long battery life
- Only temperature gauge at this point
- No Android or PC software