Science Buddies: "Ask an Expert"

I am working on the electrolyte challenge project from your website. I am having trouble getting any readings on the mulitmeter. can you tell me what setting I should have the multimeter set at? Should I be looking for amps or volts?

Christo

The settings depend on what type of power you are using so here is a link to some information about using a multimeter. I hope this helps:

https://www.sciencebuddies.org/science- ... sure.shtml

Tori

Hey Christo,

The experiment you are talking about is this one https://www.sciencebuddies.org/science- ... p053.shtml ,if I am not mistaken. According to what the project says, you should be using the multimeter as an ammeter. This means that you should be measuring current (I), which is measured in amperes or amps.

As for your other question about what setting the multimeter should be at, I found some information underneath the 'Measuring the Conductance' heading:
1. Turn the multimeter to read direct current. Make sure it is reading direct current and not alternating current (see the instructions for the multimeter).
a. Use the 200-microamps setting to read low conductance (distilled water, for example). Use the higher settings for solutions with high electrolyte concentration (sports drink).
4. a.The voltage is 9 V, which is obtained from the battery. The current is what you measure with the multimeter.

This implies that different settings should be used depending on the electrolyte concentrations of the solutions. Since you already have the voltage from the battery you are using, you just have to measure the currents with the multimeter. With those two measurements, you can then solve for conductance of each of the solutions, using the equations Conductance = (Current / Voltage).

Hope this helps!