Often, the only liquid level indicator you need is your eyes, such as when looking at your cold beverage on a summer’s day. Other times, though, it’s useful to have some kind of indicator ...

Often, the only liquid level indicator you need is your eyes, such as when looking at your cold beverage on a summer’s day. Other times, though, it’s useful to have some kind of indicat… ...

DURING the course of an investigation of the photosensitivity of silver halide precipitates, the need for a transparent, conducting electrode sensitive to halogens became evident. A new practical ...