Flame probe

Plate capacitor in the flame probe test

A flame probe is a special measuring probe in physics. It is used to prove potential differences in an E-field in experiments .

construction

A flame probe consists of a flame - from a candle, a burner, etc. - and a conductor. The conductor protrudes into the flame, the other end is connected to a voltage measuring device. The grounding usually serves as the reference potential for the measuring device . This allows you to determine the potential of the point where the flame is located.

It therefore applies:

${\displaystyle U_{\text{Mess}}=\Delta \varphi =\varphi _{\text{Sonde}}-\varphi _{\text{Bezug}}}$

For example, in a homogeneous electrical field between two capacitor plates, the potential relative to the grounded plate can be determined.

function

Gas particles are ionized by combustion and temperature . There are positive and negative charges in the air. The ionized particles transport charges away from the flame probe until their charge corresponds to the potential in the measuring point and thus does not disturb the surrounding electric field.

commitment

The flame probe is a popular physics experiment that explains the term electrical potential.

Individual evidence

1. ↑ Potential measurement with the flame probe | LEIFI physics. Retrieved November 16, 2018 .