A Gage is Just a Gauge?

Do You Ever Perform Tests Where the Data Isn’t That Important?

Significant planning and expenditure is required to perform any test. Although it’s natural to want to keep these costs to a minimum, the reality is that good quality information doesn’t come cheap. Unfortunately the cost-cutting is often done in the lowest-cost areas of a test, which, in most cases, are the sensors and associated consumables. In fact, the biggest cost is often the labor; a good-quality strain gauge installation (using even minimal material costs) can take hours to complete. The process includes preparing the surface, mixing the adhesive, installing the sensor, attaching the lead wires, testing the installation, applying the coating(s), re-testing, routing of the leads, attachment of the instrument connectors, a further electrical test for resistance and insulation, and finally a system test with the instrument fully connected which may include zero stability, noise levels, and calibration.

Considering these points, we often hear that “a gauge is just a gauge”. We know that data quality lives and dies on the quality of the basic sensor. It takes essentially the same time to install a poor sensor as it does good one; in fact, at VPG Micro-Measurements, we have unique spelling with our gage products and uncommonly better features that can significantly reduce the installation time while simultaneously improving the performance. As I mentioned in a previous article, poor or missing data has infinite cost per quantity!

The following includes important points about our products and processes that distinguish VPG as a unique manufacturer of strain gages and associated foil products:

  • VPG’s product portfolio is based primarily on foil technology
  • Foil is rolled in-house from our own fully-specified raw material
  • All foil processing is in-house (including rolling to the correct thickness, heat treatment, and other processes) all the way through to the finished product. Absolutely nothing is sub-contracted!

Foil roll

Controlling the foil entirely in-house enables VPG to create specific performance characteristics unique to us. This foil is used for both our class-leading resistors and, of course, our strain gages, the main subject for this article. This allows us to produce our gages (not your ordinary gauges) with the following superior characteristics:

  • Excellent gage-to-gage and grid-to-grid matching, to allow for more uniform gage performance at temperature
  • Tighter resistance tolerances - down to +/-0.1% even in high resistance gage patterns - to enable simpler balance of the Wheatstone Bridge circuitry
  • High-resistance patterns - offered in linear, shear, rosette and full-bridge configurations - with up to 20Khom resistance values
  • Copper or gold plated solder tabs (on Karma foil patterns) and epoxy or polyimide encapsulation for active grid protection offered as standard features
  • Excellent fatigue life, even on high-resistance patterns due to high-quality etching


Strunt calibration diagram, gages, resistor, and circuit diagram

Strain gage performance isn’t just a function of the foil, but also of the backing and bonding materials used to construct our gages. Here we further separate ourselves with unique features:

  • Proprietary-grade backings such as polyimide offer gage-to-gage and batch-to-batch performances that are consistent across years of production
  • In-house manufactured laminating adhesive to ensure continuous foil peel strength and performance

We’ve also not only converted to environmentally-friendly etching chemicals over the past few years, but re-invented our gage circuit to allow resistance adjustment by laser trimming.  Advanced Sensors Technology: the first major change to typical gauge design and manufacturing techniques since their invention in the 1950s!

We hear from partners all over the world that our gages stand head and shoulders above others for quality, consistency, reliability, durability, stability, and handling. I’ve also had a customer tell me that “when the data really matters, I use your gages”, which begs the question: Have you performed tests where the data isn’t that important? The answer is with VPG, you won’t have to ever waste time or compromise accuracy again. 

Experience the VPG Gage and Data difference. Visit micro-measurements.com

Connect with a Measurement Expert at https://micro-measurements.com/contact

achittey's picture

Anton Chittey

United Kingdom