Science Buddies: "Ask an Expert"

I am working on your science project "How Long Does It Take To Fry A Diode?".
I have completed the first seven steps which are about setting up the calibration of the diodes.
When I turn the oven on and try to take the voltage, the multimeter reads 9.2v no matter how hot the oven is.
What have I done incorrectly?

Hello and welcome to the forums

If you're reading 9.2V, then the diode is not conducting current. With a 1 M Ohm resistor, you should see around 0.2 to 0.7 V. Do you possibly have the diode hooked up backwards? If so, it is doing its job of not passing any current. Try reversing the diode and see what happens. If that doesn't help, please try other diodes - maybe you have a bad one. You should be able to get a diode to work, and it won't hurt them to connect them up backwards, so fiddle around until you get results!

Best,
Keith

Thank you

I am doing the second part of my experiment "how long does it take to fry a diode?"
I keep the same setup except outside of the oven.
And when I am soldering the diode lead the voltage reading flies all over the place.
For example 5 seconds = 8.31 volts, 15 seconds = 7.98 volts, 25 seconds = 7.56 volts, 35 seconds = 7.33 volts, 45 seconds = 7.67 volts, and at 55 seconds = 8.05 volts.
And after a while , as shown in my example, the voltage reading goes back up.
Is this ok and if so am I in the right voltage reading range.