How to Use a Durometer in a Few Easy Steps

Let's just call it what it is – getting a material’s hardness wrong can absolutely wreck a project. In the world of making and supplying things, it's the one detail you can't afford to mess up. 

At Qualitest, we see that consistent hardness is a critical property that directly impacts performance. This is where a durometer becomes an indispensable instrument. But what is a durometer used for, and how can you ensure your readings are accurate every time?

A durometer is a specialized tool that measures the indentation hardness of materials like polymers and rubbers. It works by pressing a standardized indenter into the material and measuring the depth of penetration. A higher number indicates a harder material; a lower number indicates a softer one. 

Knowing how to measure durometer effectively is a key practice for any quality assurance team dedicated to delivering reliable products.

How to Use an Analog Durometer

The analog durometer is a classic instrument, and we appreciate it for its straightforward durability and reliability in shop-floor environments. Following these steps will ensure you get a good measurement.

1. Preparation: Start with a clean, flat material sample that is at least 6mm thick. It's vital to select the correct Shore scale for your material type (e.g., Shore A for softer elastomers, Shore D for rigid plastics).

2. Positioning: Hold the durometer perfectly perpendicular to the material's surface. We always emphasize that the flat presser foot must sit flush against the sample for a valid reading.

3. Application: Apply pressure in one smooth, continuous motion. Avoid sudden impacts, as a steady application is just as important as the instrument's calibration.

4. Reading: The moment the presser foot is flat against the material, note the value indicated by the primary needle. For materials that "creep," some models feature a secondary needle that captures the peak reading, a feature we find quite practical.

5. Repetition: A single reading isn't enough for proper validation. Take 3-5 measurements in different locations, ensuring they are at least 6mm from each other and 13mm from any edge. The average of these readings is your final value.

How to Use a Digital Durometer

A digital durometer brings modern precision to the process, offering clear advantages for documentation and accuracy.

1. Prep Work: As with the analog model, prepare a clean, flat, and suitably thick sample. Power on the device.

2. Line it Up: Stand it straight up, perfectly flat on your surface.

3. Press Down: Apply smooth, firm pressure until the presser foot is making full contact with the sample.

4. Check the Screen: A big, beautiful number will pop right up. No squinting or "did I see that right?" guesswork. The best part, which we think is a game-changer, is the "peak hold" button on most of these. It freezes the highest reading it saw, so you couldn't miss it if you tried.

5. Rinse and Repeat: Take several readings across the sample. The precise digital output simplifies the process of calculating an accurate average for your quality control records.

Related article: Durometer Hardness Scale: A Complete Guide

Factors That Can Affect Your Measurement

It doesn’t matter if you have the old-school analog or the flashy digital; we see people get tripped up by the same things over and over.

- Insufficient Sample Thickness: If your sample is too thin, the durometer may be influenced by the hardness of the surface underneath it, leading to falsely high readings.

- Ambient Temperature: A material’s hardness can get seriously weird if the room is boiling hot or freezing cold. Try to test in a place that feels comfortable to a human being.

- Uneven Surfaces: Attempting to measure a curved or rough surface will prevent the presser foot from sitting flat and will always produce an unreliable result. It seems basic, but it's a frequent oversight.

Common Mistakes to Avoid

Part of using a durometer correctly is knowing what not to do. These easily avoided errors are common, but paying attention to your technique will prevent them.

- Angled Application: Holding the durometer at an angle will always, always, always give you a nonsense reading.

- Living on the Edge: Don't even think about measuring right next to the sample's edge. The material will just ooze out the side, giving you a reading that's way too low.

- Having Bad Timing: For those materials that creep, if you read one measurement instantly and the next after a few seconds, your results will be a hot mess. Be consistent.

- Using the Wrong Tool for the Job: You wouldn’t use a sledgehammer to crack a nut. Don’t use a Shore D durometer on a gummy bear. Match the tool to the material.

Read more: Shore Hardness vs. Durometer: Complete Explanation

Now You Know How to Use a Durometer, Let Qualitest Provide the Tool

Getting the hang of a durometer puts you in the driver's seat of your quality control. We know that if you follow the right moves for your tool, you can be 100% sure about your material's hardness. And that’s a massive piece of the puzzle for making seriously good stuff that doesn’t fail.

At Qualitest, we understand that dependable equipment is the foundation of a great quality control program. That’s why we offer a full range of high-performance, cost-effective analog and digital durometers that we stand behind for any application or budget. Don't let inconsistent material properties create problems in your production. 

If you're looking to improve your quality control with accurate and repeatable testing, we invite you to explore our durable, user-friendly products. Contact our experts today, and let us help you find the right solution for your needs.

Browse our range of cost-effective Durometers