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 light that ...

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 ...

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 light that ...