Simpson Solution for Permeability Testing Needs

Why Test for Permeability?

In a foundry test setting, sand permeability is defined as the time required for a controlled air volume to pass through a sand specimen or porous material. Factors that can impact permeability results include grain fineness and distribution, sand type, and moisture. Testing for permeability is critical for a foundry operation because the level of permeability can explain the causes of certain defects that can occur to metal castings. An increase in permeability can lead to penetration-type defects and rougher surface finishes. Despite leading to smoother surface finishes, a decrease in permeability can lead to casting defects such as blows, pinholes, and expansion defects.

42105 Digital Absolute Permmeter

To help a foundry meet their permeability testing needs, Simpson offers our advanced model 42105 Digital Absolute Permmeter. This electronic, high precision and fully automated device has the capability to measure permeability of various specimen types including green sand. With the addition of available accessories, the 42105 can also measure the permeability of cores, coatings, carbon composites, lost foam, and refractories such as alumino-silicate materials. Learn More & Watch How It Works

What makes the 42105 model an improvement over competitor models?

Many older version permmeters are made from fabricated housings and use electric fan technology to generate the required air pressure. Electric fan permmeters can only generate pressure and not a controlled air volume. Instead of an electric fan, the 42105 model utilizes a descending drum (Fig. 1 and 2) to generate the controlled air volume and pressure that will flow through the test specimen. To increase testing accuracy, the 42105 uses highly sensitive and accurate electronic sensors and digital timers to measure the controlled air volume that flows though the sand specimen. The 42105’s permeability function has been corrected to compensate for any fluctuations in air pressure and to eliminate the unit’s own resistance to air passage. The machine is easy to operate and very repeatable and only requires a single touch operation to conduct the permeability test. The 42105 consists of a single piece cast aluminum housing, which makes it extremely durable and sturdy during testing.

Permmeter Fig 1  Permmeter Fig 2


Testing for permeability is a critical sand lab test that would assist a foundry in explaining certain casting defects which in turn would help a foundry save in scrap related costs. The Simpson 42105 Digital Absolute Permmeter is a very popular device in the Simpson sand testing product line and is used by foundries and educational institutions worldwide. With its advanced features and simple one-touch operation, the 42105 Digital Absolute Permmeter will continue to be an integral testing device in sand laboratories all over the world.

Sand Testing Equipment

42105 Digital Absolute Permmeter in action at Lodge Manufacturing.


Sand Laboratory

42105 Digital Absolute Permmeter can be seen at PT. Octo Corindo Sarana in Bekasi Indonesia

Learn more about the Simpson Model 42105 Digital Absolute Permmeter.