Measuring the capacitance of the sensor using an LCR meter.

Uni-t Ut622a Ut622c Ut622e Lcr Digital Bridge Capacitor Tester Measuring Instrument For Inductance Resistance - Capacitance Meters - AliExpress

Measuring the capacitance of the sensor using an LCR meter.

LCR meter measurement principles

LCR meters

What's Super about Supercapacitors? – Part 3: Measuring Capacitance & ESR - element14 Community

U1700 Series Handheld Capacitance and LCR Meters

LCR Meters - Used and New

Measurement setup for capacitive sensors with a HIOKI 3532-50 LCR

E4980A Precision LCR Meter, 20 Hz to 2 MHz