Possible Alternatives to Using an Oscilloscope for

Measuring Action Potential in the Cockroach Leg

Laboratory

Matthew CroftSomerset High School

Summary

While the Measuring Action Potential in the Cockroach Leg Laboratory is interesting and worthwhile, the equipment is not commonly found in a typical high school science department.

In addition, students may have difficulty operating oscilloscopes and obtaining data.

Several alternatives to using oscilloscopes are discussed.

#1. The Poor Man’s Oscilloscope

Introduction

Source: www.ledametrix.com/oscope/

It may be possible to construct a poor man’s oscilloscope using a 3.5mm audio cable that has been separated into three wires and attached to fine pins:

Measuring Action Potential

Oscilloscope Software Example:

Audio Editing Software Examples:

Measuring Action Potential

Sample Data from Audacity:

Speaker (similar to what we did in lab without the oscilloscope)

Benefits & Drawbacks

Benefits Drawbacks

Oscilloscope Software

-Closest to original lab-Quantitative data

with graph-Data can be saved

-Purchase of Software-Possible damage to

computer-Signal is not amplified

Audio Editing Software

-Free software is available

-Quantitative data with graph

-Data can be saved

-Data is not collected in mV

-Possible damage to computer

-Signal is not amplified

Speakers-Audio response can

be rewarding to students

-Data is not quantitative

-Probably not feasible without amplifier

#2. Multimeter

Introduction

It may be possible to measure action potential on a multimeter set on mV.

Benefits & Drawbacks

Benefits Drawbacks

Multimeter -Readily available-Easy to use

-May not be sensitive enough

-Data is not displayed in graphical format

-Signal is not amplified

#3. Vernier Sensors

Introduction

Vernier LabPro and LabQuest allow you to use a wide variety of sensors to collect information. Data can be analyzed in LoggerPro.

Possible Sensors

Voltage Probe

Possible Sensors

EKG Sensor

Benefits & Drawbacks

Benefits Drawbacks

Voltage Probe

-Comes standard with LabPro

-Quantitative data with graph

-Will not damage computer

-Data can be saved and LoggerPro allows for

advanced data analysis

-Purchase of Hardware & Software

-Probe may not be sensitive enough-No ground wire

-Measurements are in V

EKG Sensor

-Quantitative data with graph

-Will not damage computer

-Three leads-Measurements are in

mV-Data can be saved and

LoggerPro allows for advanced data analysis

-Purchase of Hardware & Software

-Probe may not be sensitive enough

Ulf thinks it will work!