electrical resistance strain gauge

Constantan gives stable readings up to about 200 °C and has a well-matched thermal expansion curve for steel. Karma is better if you expect wider temperature swings or need a higher fatigue life. Our application notes include thermal output curves for both, so you can pick whichever yields less apparent strain on your material.

Many of our gauges go out with a built-in butyl rubber or multi-layer acrylic coating. It is not full waterproofing, but it handles condensation and light spray. If you need submersion, we will recommend a field-applied barrier and can walk you through the curing steps.

For a non-standard rosette, expect roughly 4 to 6 weeks from drawing approval to dispatch. Simple changes like a shorter grid length or a different resistance value usually move faster. We send a digital proof before production, and you can mark corrections directly on it.

We do not run formal training sessions, but our technical team regularly reviews photos and suggests surface prep methods, adhesive options, and leadwire routing. Most of our notes are written in plain, job-site language, not lab jargon. If the crew is new to strain gauging, we can recommend a step-by-step procedure and check the first few installations remotely.

A well-installed gauge with a proper coating can hold within a few microstrain per year. Drift depends far more on the adhesive, coating, and cable sealing than on the foil itself. We have units still reading cleanly after a decade on bridge piers, provided the protection layer was refreshed during maintenance.