CNC Machining Design Guide

Optimize your designs, reduce machining time, and lower your costs.

Injection Molding Design Guide

Guide for high quality and cost-effective plastic injection molding.

Metal 3D Printing Design Guide

Direct Metal Laser Sintering (DMLS) 3D printing for parts with reduced cost and little waste.

Selecting the Right 3D Printer

Discover how to choose the right 3D printer for your needs and the key performance attributes to consider.

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Overview

The Diaphragm Pressure Gage uses the elastic deformation of a diaphragm (i.e. membrane) instead of a liquid level to measure the difference between an unknown pressure and a reference pressure.

A typical Diaphragm pressure gage contains a capsule divided by a diaphragm, as shown in the schematic below. One side of the diaphragm is open to the external targeted pressure, PExt, and the other side is connected to a known pressure, PRef,. The pressure difference, PExt - PRef, mechanically deflects the diaphragm.

Typical Diaphragm Pressure Gage

The membrane deflection can be measured in any number of ways. For example, it can be detected via a mechanically-coupled indicating needle, an attached strain gage, a linear variable differential transformer (LVDT; see the schematic below), or with many other displacement/velocity sensors. Once known, the deflection can be converted to a pressure loading using plate theory.

LVDT-Based Diaphragm Pressure Gage
Pros and Cons

  • Pros:
  - Much faster frequency response than U tubes.
  - Accuracy up to ±0.5% of full scale.
  - Good linearity when the deflection is no larger than the order of the diaphragm thickness.
  • Cons:
  - More expensive then other pressure sensors.
Glossary
CNC Machining Design Guide

Optimize your designs, reduce machining time, and lower your costs.

Injection Molding Design Guide

Guide for high quality and cost-effective plastic injection molding.

Metal 3D Printing Design Guide

Direct Metal Laser Sintering (DMLS) 3D printing for parts with reduced cost and little waste.

Selecting the Right 3D Printer

Discover how to choose the right 3D printer for your needs and the key performance attributes to consider.