In Shore hardness testing (e.g., Shore A or Shore D), a specific indenter with a defined spring force is pressed into the material. The hardness value is determined by the depth of penetration of the indenter. Depending on the Shore method, the applied forces, the shape of the indenter, and the measuring path differ.

In IRHD hardness testing, a small spherical indenter is used. First, a light preliminary load is applied, followed by a larger main load. The hardness is then determined based on the penetration depth under both loads.

For Shore hardness testing, several standards exist, including DIN ISO 48-4, ISO 868, and ASTM D2240. These standards describe similar measurement methods but differ in details such as measurement time, scope of application, and tolerances, for example in calibration.

For IRHD hardness testing, the most important standards are DIN ISO 48-2 and ASTM D1415. They define the testing conditions and requirements to ensure precise measurement results.

Yes, with the modular digi test II testing device, you can perform multiple hardness testing methods using just one system. Thanks to interchangeable measuring units, different test methods can be applied flexibly, allowing a wide range of hardness tests with the same equipment. You only need the appropriate measuring unit for each testing method.

The choice of the right hardness testing method depends on several factors. Here is a simple guide:

1. Material type and hardness

• Soft materials such as rubber → Shore A or IRHD-N
• Harder plastics or elastomers → Shore D or IRHD-H
• Very soft materials such as foam → Shore 00 or IRHD-L

1. Sample thickness

• At least 6 mm thick? → Shore testing is possible
• Between 2 and 6 mm? → IRHD or Micro Shore for more accurate results

1. Measurement accuracy and standards

• Always take into account the required precision and the relevant standards.

Check product descriptions or data sheets, as they often specify the appropriate testing method. If you are unsure, simply send us a sample – we will find the best solution for you!

To obtain precise and reliable Shore or IRHD measurement results, you should keep the following points in mind:

1. Proper sample preparation

• Clean, flat surface: Contaminations or irregularities can distort the results.
• Sufficient sample thickness: Shore: at least 6 mm (if necessary, stack several layers) | IRHD: at least 2 mm, ideally not too thin.
• Constant environmental conditions: Temperature and humidity should comply with the standard requirements (e.g., 23°C ± 2°C, 50% ± 5% RH).

2. Choosing the right device & method

• Shore or IRHD? Select the appropriate method for your material.
• Standards-compliant testing: Ensure your testing device meets the relevant standards (e.g., ISO 48-2 for IRHD, ISO 868 for Shore).

3. Regular calibration

• Your testing devices should be calibrated regularly (e.g., annually or according to the manufacturer’s specifications).
• Checking with reference blocks helps to identify deviations at an early stage.

4. Conducting comparative measurements

• Participating in interlaboratory comparisons with other companies can provide valuable insights.
• Different testing methods or devices can reveal potential deviations.

Many factors can influence the measurement – if you have any questions, we will be happy to assist you!

For all of our hardness testers, software is required to transfer the measurement data to a PC or an evaluation tool. If you would like to integrate the protocol into an existing interface, this is also possible. Simply contact us, and we will discuss the details of the data interface with you. In addition, you can find initial information on this topic in the operating manual.

For the entire portfolio in the field of rubber and plastics, we recommend our BareissOne software. This solution offers comprehensive functions for data analysis and management.

In the pharmaceutical sector, our Bareiss Celeste software is the ideal tool, specifically tailored to the requirements of this industry.

For HP Digital applications, we offer the Datatool software, which enables easy transfer of measurement values to Excel, allowing you to manage your data quickly and efficiently.

Maintenance means that a device is regularly checked, cleaned, or repaired to ensure it functions properly. For example, in a car, the oil is changed, or the brakes are inspected.

Calibration means verifying whether a device displays correct values. It is compared against a known standard. For instance, if a thermometer should show 20 °C but indicates 22 °C, it must be readjusted, or at least this deviation must be documented.

Validation checks whether an entire process works as intended and delivers reliable results – for example, whether a device is capable of consistently producing the same measurement results.

In summary:

• Maintenance keeps devices operational.

• Calibration ensures accuracy.

• Validation confirms that the overall process delivers reliable results.

Specifically for hardness testers, the definitions of these terms are as follows:

The calibration frequency of your hardness tester depends on several factors, such as standard requirements, internal quality guidelines, and frequency of use. As the manufacturer, we recommend annual calibration. This regular calibration not only forms the basis for your quality assurance but, with the included maintenance, also ensures the long service life of your hardness tester.

Between calibrations, we recommend regularly checking your hardness tester with reference blocks. The frequency of these checks depends on how often the device is used:

• Frequent use: we recommend checking daily or weekly.
• Infrequent use: the device should be checked before each use.

These measures help ensure the accuracy of your measurement results and maintain the quality of your testing.

With reference blocks, you can check the measuring path, the spring force, and the geometry of the indenter of your hardness tester between calibration intervals.

With control rings, you can check the measuring path of your hardness tester between calibration intervals.

A reference block must be calibrated at least once a year, as required by standards such as DIN ISO 48-4 for Shore. However, if you notice deviations or if the reference block already shows too many indentations, it may be necessary to shorten the calibration interval. This ensures that your measurement results always remain accurate and reliable.

When using hardness testers, there are many factors that can influence the hardness value.

1. Hardness testing with tabletop devices

When performing hardness testing with tabletop devices such as the digi test II, it is important that both the test table and the underside of the reference block are free from contamination. The surface of the reference block must also be clean to ensure accurate measurement results. Further information on this can be found in the reference block manual.

2. Use of handheld hardness testers

When using handheld hardness testers, make sure that the device is applied perpendicularly and with appropriate speed. Our unique pressing mechanism ensures that the correct contact force is applied directly.

If you use a handheld hardness tester with a test stand, it must be ensured that the tester is aligned perpendicular to the test table. This guarantees precise and reliable measurements.

If your reference block shows incorrect measurement values, you should first check the following points:

1. Calibration

• When was the last calibration of your hardness tester?
• When was the last calibration of your reference block?

2. Condition of the equipment

• Are there any signs of contamination or damage to your testing system or the reference block?

3. Additional checks for Shore D

• Was the surface recently ground? The block may already have too many indentations.
• Has the required additional weight been applied?

4. Foam reference blocks

• Make sure not to touch foam reference blocks with your fingers, as they are sensitive materials designed only for verification with the specified testing instrument.

By performing these checks, you can identify potential sources of error and ensure the accuracy of your measurements.