As Mars rotated, bringing different areas into view of the telescope, the scientists could measure variations in the concentrations.

Scientists have invented instruments that measure variations in gravitational force, but they're much, much more sensitive than the human body.

Level 4 Be able to measure variations in living organisms.

Gradiometer any device that measures spatial variations of a physical quantity.

You walk along the ground and it measures tiny variations in the local magnetic field.

"Measuring gravitational variations gives us a window for watching the transport of masses around the planet, changes that can affect climate and many other things."

Chandra has been able to measure variations of temperature, density, and pressure with high resolution.

The sensors are able to measure subtle variations in temperatures on the ground.

It took another week to bring all the equipment to the summit, including a pendulum designed for measuring slight variations in gravity.

In 1932, a quartz clock able to measure small weekly variations in the rotation rate of the Earth was developed.