Technology Tools
Consider a student 100 years ago, in 1907: electricity is available
in places, radio is just being invented, no TV, no electronics,
experimental flight, rudimentary knowledge of medicine,
astronomy, physics, chemistry, biology and the world around
them. Communication is by letters delivered by train or ship, and
the concept of an internet is beyond imagination. How did these
students learn, and more importantly, what made them interested
in science? Fast forward to the present, or more precisely, about
10 minutes into the future, where our students now live: the
internet is almost ubiquitous, cell phones, IM chat, and online
media are commonplace, and so are the tools available to them.
How can we use these tools to inspire our students, building
on what might have inspired them 100 years ago? As teachers,
we know that curiosity and exploration are key elements in a
successful learning experience. When students are exploring or
inventing, there is no clock on the wall, and they need no urging
to become engaged. Our vision is to capitalize on the emerging
technologies already familiar to our students, augment them with
new science and technologies, even prototypes that have not seen
the consumer market, and enable our students to adapt, invent, and
create a learning experience of their own.

ASOF Curriculum Guide (Chapter 4)

Concord Consortium ~ Realizing the Promise of Educational Technology
Carolyn Staudt (E-mail: carolyn@concord.org)

Web blog by Carolyn Staudt on the Denali/Alaska trip (Sept. 2007):
http://web.mac.com/cjstaudt/ASOFDS/Welcome.html

In preparation for the call this future postings, I am sending you a new URL. It is greatly improved and has features that will now allow collaboration.

http://onrdiy.concord.org/

I have left the starter activities from the Alyeska workshop. Now that the functionality has been improved, additional activities with the sensors by teachers, students, and me can be added.

The ASOF Do It Yourself web portal allows anybody to make their own simple probeware activities and publish them on the web for their colleagues and students to use. Probeware activities can be used with probeware interfaces form multiple different probeware vendors, including the Vernier GoLink.

Registering and Logging In

When you register and login any work you do either creating or running activities will be saved by the ONR DIY Portal for you and will be there the next time you connect.

*** Important note for MacOS X users ***
There is small a bug in Apple's Java releases versions 1.5.0_06 and 1.5.0_07 that will cause the downloading of the Java web start applications to freeze the second time you try using them.  We created 'Fix Java Web Start' -- a small program that fixes this problem. There is a link on the home page of the site to this program and you can get it directly at the url below:

http://onrdiy.concord.org/FixJavaWebStart.dmg

Running Activities

Any of the Activities that authors have made publicly visible can be run as a Java web start application on your computer by clicking the 'Run' link. You need Java 1.5 or later installed on your computer. At the bottom of the page on the left is a link to your simple Java Webstart Checker.

Create and publish your own Activity

You can easily create a new activity from the 'Activity Listing' page. You can start by either clicking the 'Create New Activity' link at the top of the page. This gives you a brand new blank activity to start with. Or you can start by copying someone else's activity by clicking the 'Copy' link at the left of each activity listed.

Sharing your Activity with other people

When you create or edit an activity as he author you can decide whether you want the activity listed as 'Public'. This is available as a check box on the Create or Edit activity pages.

Seeing other peoples work when they ran your Activities
At the bottom of each activity listing is a link to a Usage page, which allows you (and anybody else) to see who has run your activity. You can 'View' the work that people have done from this page by clicking on their name. When you 'View' instead of 'Run' and activity no data will be saved back to the ASOF DIY web portal.



Frequently Asked Questions (FAQs) on ASOF Vernier Probe Kit Sensors:

This list has been compiled based on questions asked during training in February 2-3, 2007 at Alyeska, Alaska. Please feel free to ask any additional questions and they will be added to the list.

CO2
Q: How does this sensor work?
A: The CO2 Gas sensor measures gaseous carbon dioxide levels in the range of 0 to 5000 ppm by monitoring the amount of infrared radiation absorbed by carbon dioxide molecules. The sensor uses a hot metal filament as an infrared source to generate infrared radiation (IR). The IR source is located at one end of the sensor’s shaft. At the other end of the shaft is an infrared sensor that measures how much radiation gets through the sample without being absorbed by the carbon dioxide molecules. The detector measures infrared radiation absorbed in the narrow band centered at 4260 nm. The greater the concentration of the absorbing gas in the sampling tube, the less radiation will make it from the source through the sensor tube to the IR detector. The temperature increase in the infrared sensor produces a voltage that is amplified and read by the software.

Q: Are there any special needs for power for the CO2 Gas sensor?
A: The CO2 Gas sensor needs to be powered during reading. An additional power supply has been provided. Also, provide sufficient time for the CO2 Gas sensor to warm up and stabilize.

Q: Is there a temperature range at which the CO2 Gas sensor is most accurate?
A: The CO2 Gas sensor is designed to operate between 20°C and 30°C. The
CO2 Gas sensor can be used outside of this temperature range; however, you should be aware that there will be a loss in accuracy of readings. This does not prohibit taking readings using incubation temperatures or outdoor readings at temperatures warmer or colder than the 20 to 30°C range. Allow enough time for your CO2 Gas sensor to stabilize at the desired operating temperatures.

Q: Do I need to calibrate this sensor?
A: You should not have to perform a new calibration when using the CO2 Gas sensor in the classroom. The sensor has been set to match a stored calibration before shipping it. You can simply use the appropriate calibration file that is stored in your data-collection program. If you do find that you need to reset your CO2 Gas sensor, it can be reset using one known CO2 level. Note: This calibration method is different than the usual two-point calibration performed using other sensors. To reset the CO2 Gas sensor in units of parts per million (ppm) you will need to place the sensor in the 250 mL collection bottle (included with your sensor) in the air outside your building long enough to ensure that its contents are replaced with fresh air. The calibration will be based on this sample having a carbon dioxide concentration of about 400 ppm.  While still outdoors (with the slit rubber stopper on the sensor tube of the CO2 Gas sensor), insert the stopper into the gas-sampling bottle containing fresh outside air. Do this by holding the stopper, not the probe box. You can now take the bottle and sensor to the location where the calibration is to be done (either outside or back in the classroom). Connect the CO2 Gas sensor to the interface. Start the data-collection program. Let the sensor warm up by collecting data for at least 90 seconds. You can monitor the CO2 reading by simply observing the live display on the computer data-collection software. When the CO2 Gas sensor has warmed up (readings should have stabilized), use a paper clip or the point of a mechanical pencil to press down the calibration button. Release the button immediately after the Red LED blinks rapidly three times. After about 30 seconds, the reading should stabilize at a value of approximately 400 ppm (±50 ppm). If the reading is significantly lower or higher than
400 ppm, simple press the button again to repeat the process.

Q: Is there an online User Guide?
A: Available at http://www2.vernier.com/booklets/co2-bta.pdf

Infrared (IR) Thermometer
Q: Do I need to calibrate this sensor?
A: The Infrared Thermometer is automatically (auto ID) detected and calibrated when connected.

Q: Is the laser pointer dangerous?
A: This sensor contains a laser that can be turned on and off. As with any laser, caution must be exercised when using the sensor. The sensor emits laser radiation, and therefore, should not be pointed at the eye. Pay special attention to the location of the aperture, which is located next to the sensing element. Pay special attention to the location of the aperture, which is located next to the sensing element. Direct eye contact with the laser beam may cause serious injury. Students should be reminded that this is not a toy, and it should be kept out of reach of children.

Q: Is there a way to switch from Celsius to Fahrenheit readings?
A: The sensor reading will appear in °C. When connected to a data-collection interface, data can be collected in other units, e.g., °F and K. If you are using Logger Pro software, an alternative is to open an experiment file in the Logger Pro Probes & Sensors folder. The Infrared Thermometer folder contains other experiment files and calibrations, including one for temperature in °F (Fahrenheit), and another in K (Kelvin).

Q: Is there an online User Guide?
A: Available at http://www2.vernier.com/booklets/irt-bta.pdf

O2
Q: How does this sensor work?
A: The O2 Gas Sensor is used to monitor gaseous oxygen. The O2 Gas Sensor measures the oxygen concentration in the range of 0 to 27% using an electrochemical cell. The cell contains a lead anode and a gold cathode immersed in an electrolyte. When oxygen molecules enter the cell, they get electrochemically reduced at the gold cathode. This electrochemical reaction generates a current that is proportional to the oxygen concentration between the electrodes. The current is measured across a resistance to generate a small voltage output.

Q: Do I need to calibrate this sensor?
A: For many measurements, it will not be necessary to calibrate the O2 Gas Sensor. The sensor has been set to match a stored calibration before shipping it. You can simply use the appropriate calibration file, which is stored in your data-collection program.  For more accurate measurements, the sensor can be calibrated at 0 and 20.9% oxygen. Follow the normal 2-point calibration procedure. For the first point, push and hold the zero button located on the top of the sensor. Enter a value of 0 for this reading. Release the button and take a second reading. Enter a value of 20.9% oxygen or a corrected value from the table below. Once finished, the sensor should now read 20.9 (or the value entered from the table below) while resting in the gas-sampling bottle. To calibrate in parts per thousand, multiply the second value by 10 (for example, you would enter 209 instead of 20.9).

Q: Is there an online User Guide?
A: Available at http://www2.vernier.com/booklets/o2-bta.pdf

pH
Q: Do I need to calibrate this sensor?
A: You should not have to perform a new calibration when using the pH sensor for most experiments in the classroom. The sensor has been set to match a stored calibration before shipping it. You can simply use the appropriate calibration file that is stored in your data-collection program from Vernier. If it should not be necessary to calibrate the pH sensor, you can use the 2-point calibration option of the Vernier data-collection program. Rinse the tip of the electrode in distilled water. Place the electrode into one of the buffer solutions (e.g., pH 4). When the voltage reading displayed on the computer screen stabilizes, enter a pH value, “4”. For the next calibration point, rinse the electrode and place it into a second buffer solution (e.g., pH 7). When the displayed voltage stabilizes, enter a pH value, “7”. Rinse the electrode with distilled water and place it in the sample to be measured. In order to do a calibration of the pH Sensor, or to confirm that a saved pH calibration is accurate, you need to have a supply of pH buffer solutions that cover the range of pH values you will be measuring. We recommend buffer solutions of pH 4, 7, or 10.

Q: How do I best store the pH sensor?
A: Long-term storage (more than 24 hours): Store the electrode in a buffer pH-4/Kcl storage solution in the storage bottle. The pH Electrode is shipped in this solution.
Vernier sells 500 mL bottles of replacement pH Storage Solution.

Q: Is there an online User Guide?
A: Available at http://www2.vernier.com/booklets/ph-bta.pdf

Salinity

Q: What does the salinity sensor measure?
A: The salinity sensor measures the total-dissolved salt content in water. The Vernier Salinity Sensor has a range of 0 to 50 ppt. This means it can be used to measure water with a wide variety of salinities, from freshwater to ocean water, and even hyper-saline environments. The sensor measures the ability of a solution to conduct an electric current between two electrodes.

Q: Are there any special needs while storing the sensor?
A: When you have finished using the Salinity Sensor, simply rinse it off with distilled water and blot it dry using a paper towel or lab wipe. The probe can then be stored dry.

Q: Do I need to calibrate this sensor?
A: In most cases, the answer is no. Each Salinity sensor is individually calibrated before it is shipped. This calibration is stored on the sensor and will be used by default. If you wish to calibrate the Salinity Sensor yourself, you may do so using a two-point calibration. Simply perform the first calibration point with the probe out of any liquid or solution (e.g., in the air). A very small voltage reading will be displayed on the computer. Place the Salinity Sensor into a standard solution (solution of known concentration) for the second calibration point. Be sure the entire elongated hole with the electrode surfaces is submerged in the solution. Wait for the displayed voltage to stabilize. Enter the value of the standard solution (e.g., 35 ppt).

Q: How do salinity readings change based on temperature?
A: The Salinity Sensor is automatically temperature compensated between temperatures of 5 and 35°C. Readings are automatically referenced to a conductivity value at 25°C; therefore, the Salinity Sensor will give the same conductivity reading in a solution that is at 15°C as it would if the same solution were warmed to 25°C. This means you can calibrate your probe in the lab, and then use these stored calibrations to take readings in colder (or warmer) water in a lake or stream. If the probe was not temperature compensated, you would notice a change in the conductivity reading as temperature changed, even though the actual ion concentration did not change.

Q: Is there an online User Guide?
A: Available at http://www2.vernier.com/booklets/sal-bta.pdf

Stainless Steel Temperature probe
Q: How durable is this sensor?
A: This is a very durable sensor. It can be used in chemicals, boiling water, and weather studies. However, the black molded plastic handle is not waterproof and should not be submerged.

Q: Do I need to calibrate this sensor?
A: In most cases, the Stainless Steel Temperature Probe will never need to be calibrated. It is calibrated extremely well before it ships. However, if the need arises to calibrate the sensor, the sensor can be custom-calibrated. The process of calibrating a Stainless Steel Temperature probe is different than the process for most other sensors. One reason is that this probe uses a thermistor, which has a non-linear response, and you need to calibrate it at three different temperatures, as opposed to a two-point calibration.

Q: Is there an online User Guide?
A: Available at http://www2.vernier.com/booklets/tmp-bta.pdf