Micro Hardness Tester

What is Micro Hardness Testing?

Micro hardness testing is a method that applies a compressive load to individual microscopic particles to quantitatively evaluate their fracture strength and deformation behavior. In the optimization of powder processes and quality control, understanding the mechanical properties of individual particles is essential, serving as a critical indicator directly linked to process design such as granulation, coating, and drying. The MHT-1 is an automatic compression testing device (Micro Hardness Tester) specifically designed for the microscopic particle range, which was difficult to handle with conventional hardness testers.

The Importance of the 40–400 μm Measurement Range

In modern advanced industries, such as pharmaceutical microparticles, fine powders for electronic materials, and fine powder food additives, the particle size range of tens to hundreds of micrometers is frequently handled. This range often falls below the lower limit of conventional individual particle hardness testers, creating a gap in measurement capabilities. By changing the measurement stage, the MHT-1 realizes compression testing for fine particles from 40 to 400 μm (40 to 120 μm for the high-resolution MHT-1W model), effectively covering this blank area.

Full Automation via Proprietary Dispersion Sampling and Image Analysis

Manually placing and accurately measuring microscopic particles one by one on a stage is extremely difficult. The MHT-1 utilizes our proprietary technology to automatically disperse and sample particles one by one. Furthermore, it employs "advanced image analysis" to automatically exclude overlapping particles and agglomerates from the measurement, recognizing and testing only single, isolated particles. The operator simply loads the sample, and the device automatically repeats the cycle from compression testing to cleaning for up to 500 particles per specimen.

Precise Recording of the Fracture Process

Beyond mere numerical strength values, the MHT-1 precisely records the process from compression to fracture using both "image data" and "load-displacement curves". By selecting any particle from the measurement results, users can visually confirm and analyze the fracture process through continuous images synchronized with the load-displacement curve.

Comparison and Segregation with the AHT1000

Asahi Souken's Pellet Hardness Tester "AHT1000 (Fully Automatic Individual Particle Compression Tester)" is a highly proven device targeting relatively large particles from 200 to 1500 μm.

• MHT-1: 40 to 400 μm (Microscopic particles such as fine powders and microgranules)
• AHT1000: 200 to 1500 μm (Relatively large particles such as pellets and granules) By utilizing both devices, a comprehensive hardness evaluation system spanning the entire powder process—from raw microscopic powders to final granulated pellets—can be established.

Main Applications

• Pharmaceuticals: Film strength evaluation of microparticle coatings, granulation strength management of microgranules, and quality inspection of carrier particles for DPIs (Dry Powder Inhalers).
• Advanced/Electronic Materials: Hardness evaluation of advanced materials requiring high quality standards, such as ceramic microparticles, metal powders, toner particles, and catalyst carriers.
• Food and Cosmetics: Quantitative management of the strength and disintegration of fine particles—such as powdered seasonings, powdered flavors, and cosmetic powders—that directly affect product texture and dissolution characteristics.

Main Specifications

• Model: MHT-1 / MHT-1W (High-resolution model)
• Target Particle Size: 50 to 400 μm (1 mm for manual measurement; 40 to 120 μm for MHT-1W) *Requires stage change
• Measurement Items: Maximum particle size, peak load, displacement, compressive strength, fracture strength, deformation strength
• Number of Measured Particles: Up to 500 particles per specimen (continuous measurement)
• Descent Speed: Selectable from 1.0 to 10 μm/sec (0.31 to 10 μm/sec for MHT-1W)