The humble electronic thermometer is often the gateway technology into the world of digital data collection, and Pasco Scientific just made that tech much more affordable. And Bluetooth to boot! Whether measuring thermal motion at -40 degrees C which happens to be about the freezing point of Mercury, to 125 degrees C which happens to be the melting point of Iodine, the Pasco Wireless Temperature Sensor will do the job.
Using a stainless steel probe of 12cm in length and 5mm in diameter is topped with a boxy gasket-sealed plastic housing, the device is simple to use, familiar in design, and both large enough and small enough for most classroom activities.
What separates this particular probe from others on the market, and also a likely factor explaining its low price, is that the Pasco Wireless Temperature Sensor 1) uses a user-replacable CR2032 coin battery, 2) contains no on-board display with two indicator LEDs (one for on/off status and one for Bluetooth) providing all visible probe-side activity. And compared to other sensors in this form factor, there is no mistaking the blinking lights as they are quite conspicuous which is a good thing. And 3) the Pasco Wireless Temperature Sensor is just a radio transmitter beeping a short-range data point as often as 10 times a second. The technology for measuring temperature and popping off a radio blip is well dialed-in so the cost of materials to build a sensor such has this has come down drastically in the past few years. So all the heavy lifting (data visualization and manipulation) is done by the competing device that the Pasco Wireless Temperature Sensor is talking to.
An note about the batteries: The three volt CR2032 cell that the Pasco Wireless Temperature Sensor uses is a very common size that can be purchased in most grocery stores. However, the cost of one battery might be the same as a half-dozen or more batteries when purchased in bulk. Pasco sells the batteries for a buck a piece when you by 10. When I wander the digital isles of Amazon.com and often can find name-brand coin cells for around that price as well.
The Internet of Things (IoT)
The year 2013 was a big deal for IoT in that a perfect storm of technology intersected allowing us to vastly improve and increase our wired and wirelessly connected electronics. A leader in the IoT revolution was Bluetooth. Not the medieval 10th century king, but the wireless technology standard. And today the Pasco Wireless Temperature Sensor uses Version 4.0 Bluetooth also known as Low Energy Bluetooth, or BLE, or Bluetooth Smart. We are actually up to Bluetooth 4.2 as of this writing, but the security and extended packet lengths are not needed with temperature sensors.
A student, an 8th grade science aficionado to be more specific, took the Pasco Wireless Temperature Sensor for a spin on the river. Normally the weather would have the numbers in the single digits or even the thermodynamically absurd negative numbers, to this day was more like April or May than February in Montana.
Although the Pasco Wireless Temperature Sensor should survive brief total submersion in water due to it’s O-ring seals, only the metal probe should be immersed in the fluid to be measured. For this reason, I lightly sealed the probe’s head in a small zip-closure bag which also provided an attachment point to which a length of cord could connect the probe to the user.
After pairing the Pasco Wireless Temperature Sensor with an iPad Mini on shore, the student began moving away from dry land to test the range of the sensor. After a few repeated measurements, the Mini lost contact at about 33 meters, line of sight. I look forward to testing the distance with larger appliances including the iPad Pro.
The simplicity and intuitiveness of the Pasco Wireless Temperature Sensor makes using it, even for the first time, simple. Once on, the latest version of the SparkVue app is opened on almost any current device, and the Bluetooth button pushed. The Pasco Wireless Temperature Sensor pops up as a choice. Once selected, SparkVue is operated like it normally is with hardwired sensors.
At the end of the day on a Montana river in February, the sun was setting, the temperature dropping, and the margin of error between science fun and stupid was getting smaller.
In the end, this first adventure with the Pasco Wireless Temperature Sensor turned out well. The sensor preformed as advertised, and the temperatures were interesting and investigative, not life threatening which is always a good thing.