Geiger counter: to measure fluctuations in radiation.

A simpler arrangement to measure fluctuations is a negatively-biased electrode flanked by two floating electrodes.

Computers that measure altitude contain altimeters that measure fluctuations in air pressure.

These stations measure fluctuations in the Earth's electromagnetic field that correspond with seismic activity.

"The signal was so weak it wasn't even detected until 1965, and now they're measuring fluctuations of one part in 100,000."

By measuring fluctuations in their brightness, we know that many asteroids rotate in periods of three to 30 days.

A lunar-surface magnetometer to measure fluctuations in the magnetic field at the Moon.

By measuring fluctuations in a current sent through the semiconductor, the device can calculate the amount of alcohol in the breath sample.

Once she'd set up the polybarometer to measure fluctuations here, it would be as if she held a stethoscope to the heartbeat of the house.

The Consumer Price Index does not measure fluctuations in housing prices.