The Caliper

A Publication for Users of Vernier Products

Volume 22, Number 2

Fall 2005

Data Collection Made Easy

With the new Vernier EasyLink and any one of 30 different Vernier sensors, data collection with TI graphing calculators just got easier and more affordable. EasyLink is a single-channel analog interface that plugs into the mini-USB port on a TI-84 Plus or TI-84 Plus Silver Edition graphing calculator. Priced at only $58, EasyLink is an affordable way to get started with calculator data collection.

Investigating Boyle's law with EasyLink

How easy is data collection with EasyLink and a TI-84 Plus? Simply connect your sensor to an EasyLink and plug EasyLink into the mini-USB port on the calculator. The EasyData application automatically launches and identifies the sensor, and you are ready to collect data. It's as easy as that! (If your TI-84 Plus calculator was manufactured prior to January 2005, your calculator may not have the EasyData App. You can download the free EasyData App from our web site at www.vernier.com/easydata)

Thirty Vernier sensors can be used with EasyLink. Even more sensors will be supported with the release of EasyData 2.0 in November. (EasyData 2.0 will be preloaded on TI-84 Plus calculators manufactured in 2006.)

Sensors supported by EasyData and EasyLink

Additional sensors supported by EasyData 2.0 (available November 2005):

Dissolved Oxygen Sensor, EKG Sensor, Ammonium Ion-Selective Electrode, Calcium Ion-Selective Electrode, Chloride Ion-Selective Electrode, Nitrate Ion-Selective Electrode, Sound Level Meter, Turbidity Sensor.

Vernier EasyLink FAQs

Can I collect data using two or more sensors with EasyLink?
EasyLink is a single port analog interface; therefore only one sensor per calculator can be used for data collection. We recommend that you use a LabPro or CBL 2 interface for experiments that require two or more sensors.

How do I collect data using digital probes and a TI-84 Plus calculator?
Digital probes, such as Motion Detectors, Photogates, and Radiation Monitors, cannot be used with EasyLink. For motion experiments, we recommend the CBR 2 by Texas Instruments, which is supported by the EasyData application. All other digital probes require the use of a LabPro or CBL 2 interface.

Can I use EasyLink with sensors that I already own?
If the sensors you own are listed above and will auto ID when using a CBL 2 or LabPro, then your sensors will work with EasyLink. Unfortunately, older sensors that have a DIN plug or do not auto ID are not supported by EasyData 1.0, but may be supported with EasyData 2.0. Contact us for more information.

Does the DataMate App support EasyLink?
No. The DataMate App does not have the capability to communicate with the USB port on a TI-84 Plus calculator. EasyLink and EasyTemp require you to use the EasyData App. EasyData 2.0, available in November, will have additional setup and analysis functionality, making it more comparable to the current version of DataMate.

Vernier EasyLink | Order Code EZ-LINK | $58

Inverse Variation in Pressure Data: A Sample Activity Using EasyLink

Here is a data-collection activity that you can use with your math and science students. The activity describes collecting and analyzing pressure vs. volume (Boyle's law) data using a Gas Pressure Sensor, a Vernier EasyLink, and a TI-84 Plus graphing calculator.

Data Collection

Adjust the syringe that comes with the Gas Pressure Sensor so that it holds 10 mL of air before it is attached to the sensor. Set up the EasyData App to collect data using the Events with Entry option. Collect pressure measurements when the volume of the syringe is adjusted to values of 5, 7, 10, 12, 15, 17, and 20 mL. Add .08 mL to each volume before entering to account for the additional air inside the Gas Pressure Sensor. This ensures the most accurate data possible.

Data Analysis

The analysis of the data directs students through logical steps to help them determine the best mathematical model to describe the data. Students are asked to predict possible values for the x- and y- intercepts by associating conditions of the data collection to these values; for example, pressure values as the volume gets close to zero. Students then use that information to eliminate different functions as possible models for the data. Once students have eliminated linear and exponential models, they are asked to explore a rational function model (y = k/x) and manually adjust the value of k to visually fit the data.

The activity goes on to explore the connection between the model y = k/x and a definition for inverse variation that involves the product of the variables being constant. The students get a wonderful aha moment when they realize that PV = K and y = k/x are restatements of the same mathematical principle.

To download this free activity, visit our web site at www.vernier.com/easylink

EasyData screenshot 1 EasyData screenshot 2

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