# How Arnold Beckman Invented the Modern pH Meter

> A 1936 invention by Arnold Beckman that created the first reliable, portable device for measuring the acidity of chemical solutions using electronic sensors.

- **Patent:** US 2058761
- **Original title:** Apparatus for testing acidity
- **Owner:** Arnold O. Beckman
- **Granted:** 1936
- **Status:** Active
- **Times cited:** 17
- **Field:** biotech, mechanical, semiconductors

## What it does

This patent describes an apparatus designed to measure the acidity or alkalinity of a substance, known as pH. It utilizes a glass electrode system to detect electrical potential differences in a solution, which are then amplified to provide a readable measurement. By converting chemical activity into a stable electronic signal, the device allowed for precise monitoring of industrial and laboratory processes that previously relied on imprecise color-matching indicators.

## What it does NOT cover

- Does not cover digital, microprocessor-based pH sensors developed decades later.
- Does not cover non-electronic methods of measuring acidity, such as litmus paper or chemical titration.
- Does not cover the underlying scientific theory of ion concentration in solutions.

## The clever bit

Beckman realized that the high electrical resistance of glass electrodes required a specialized vacuum tube amplifier to provide a stable reading, solving the problem of signal interference that plagued earlier attempts.

## Real-world examples

1. Modern digital pH meters used in water quality testing
2. Laboratory equipment for chemical synthesis
3. Industrial process control for food and beverage production

## Why it matters

This invention was the foundation of Beckman Instruments, a company that became a titan in scientific instrumentation. It transformed chemical analysis from a slow, manual task into a rapid, electronic process, which was essential for the growth of the modern chemical and pharmaceutical industries.

## Frequently asked questions

### What does How Arnold Beckman Invented the Modern pH Meter cover?

A 1936 invention by Arnold Beckman that created the first reliable, portable device for measuring the acidity of chemical solutions using electronic sensors.

### Who owns patent US 2058761?

Arnold O. Beckman owns this patent, granted in 1936.

### When does this patent expire?

This patent has expired and is now in the public domain — anyone can use the invention freely.

### What is patent US 2058761 cited by?

This patent has been cited by 17 later patents that build on its ideas.

### What problem does this patent solve?

This invention was the foundation of Beckman Instruments, a company that became a titan in scientific instrumentation. It transformed chemical analysis from a slow, manual task into a rapid, electronic process, which was essential for the growth of the modern chemical and pharmaceutical industries.

### What does this patent NOT cover?

Does not cover digital, microprocessor-based pH sensors developed decades later.

**Full plain-English explainer:** https://patentbrief.org/patent/us/2058761/ph-meter-beckman

**Original patent:** https://patents.google.com/patent/US2058761

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


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