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Home > Clerc Center > Probes Offer a New Dimension to MSSD Lab Experiments

Probes Offer a New Dimension to MSSD Lab Experiments

Image:  PASCO digital probes (in foreground) automatically measure temperature change

PASCO digital probes (in foreground) automatically measure temperature change

Image: Students discussing data count

Students discussing data count

Image: Students time and record temperature changes

Students time and record temperature changes

Image: Here are the temperature graphs of the two probes. The graphs show the following: When the ice was melting to water, its temperature changed only a little. However, when it was completely liquid, its temperature rose dramatically. The solid coconut oil’s temperature changed even less while it was melting, but when the melting was complete its temperature shot up at a faster rate than the water’s did. The PASCO probes enabled the students to capture a continuous temperature record, with some interesting subtle areas that will challenge the students to think and explain. experiment.

Here are the temperature graphs of the two probes. The graphs show the following: When the ice was melting to water, its temperature changed only a little. However, when it was completely liquid, its temperature rose dramatically. The solid coconut oil’s temperature changed even less while it was melting, but when the melting was complete its temperature shot up at a faster rate than the water’s did. The PASCO probes enabled the students to capture a continuous temperature record, with some interesting subtle areas that will challenge the students to think and explain. experiment.

Probes Offer a New Dimension to MSSD Lab Experiments

Which heats faster-solid coconut oil or water? Students in the Model Secondary School for the Deaf (MSSD) physical science class predicted the oil would heat faster based on their experience with cooking oil. With their science teacher, Amber Marchut, they set up an experiment using probes and thermometers to test how substances absorb energy.

Incorporating probes into lab work is a new approach to scientific inquiry at MSSD. This September several MSSD science teachers and a science teacher from Kendall Demonstration Elementary School took a training course with the scientific equipment manufacturer PASCO on using probes (or sensors) to make measurements and collect data.

"I had seen the probes before but did not know how to use them. I was curious," said Marchut. "For our first lab this fall, I mainly just wanted the students to see how the probes work and to understand how we can use the technology to answer our scientific questions. We started out with using a temperature probe."

Marchut set up on a table in the center of the lab for the monitoring equipment which included two temperature probes, each inserted into a beaker-one with solid coconut oil (like frozen lard) and the other with ice. The temperature information readings from the probes were automatically projected via a laptop computer onto a screen in the classroom. Meanwhile the students at their work stations on the perimeter of the lab measured the same substance temperature changes using thermometers and recorded the data every minute for about 15 minutes.

"The graph from the probes clearly showed that the solid coconut oil and the ice stayed at a nearly constant temperature as they melted. Once they reached a liquid state, they then both fairly quickly started to increase in temperature. During the increase the oil got hot faster-showing that the two substances have different thermal properties. The students' sense about that from cooking was shown to be right!" said Marchut. 

At the end of the observation period the students had a list of minute-by-minute data with thermometer measurements for each substance. However, the probe data provided an immediate visual of what was happening as the experiment progressed. "The students really liked being able to watch the graph develop and see what was happening to the temperature. Seeing it happen in real time helps them to understand the concepts much more thoroughly. We have lots to discuss about the probe readout during our next class periods," said Marchut.

For more information on probes and training with probeware, visit PASCO.