pH meter
device · 1934 · Electric age
An electronic acidity meter (Beckman).
What it is made of
- Glass ph electrode — has part. Sensitive to the concentration of hydrogen ions.
- Reference electrode — has part. It provides a stable reference potential.
- Amplifier — has part. It amplifies the weak signal of the electrode.
- Liquid-crystal display — has part. An indicator.
Principles and materials it uses
- Electrochemical reaction — uses. A glass electrode.
- Glass — is made of. The electrode is a glass membrane.
- Silver — is made of. The internal electrode is silver chloride.
History: what it evolved from and what it influenced
- Litmus — evolved from. A replacement for indicators.