A low-cost RLC meter can be used to illustrate the concept of absolute capacitance. Here, we'll measure the capacitance between a piece of aluminum foil and something much larger and distant.

Preparation Required:  Students need to be able to calibrate and operate an RLC meter. 

Equipment Required: 

• low-cost RLC meter with Kelvin probes
• access to building ground or large metal object (e.g. a metal desk or cabinet)
• sheet of aluminum foil (approximately 20 cm x 20 cm)
• jumper wire with alligator clips (approximately 50 cm long)

Step 1: Set the RLC meter to measure capacitance at 10 kHz or 100 kHz. Perform calibrations with the Kelvin probes open and shorted. Note the range of values displayed when the probes are open. 

Step 2: Connect one of the probes to a large metal object such as a desk, cabinet, or anything that is electrically connected to the building ground.

Step 3: Note the capacitance reading. How much has it changed compared to having both probes unconnected?

Step 4: Connect the other Kelvin probe to the aluminum foil using the jumper wire. The measured value is the capacitance between the foil and the much larger metal object.

Step 5: Change the position of the aluminum foil and note how it changes. With the .....

Notes: 

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