This is the newest type of Shore hardness meter in the market, used for Shore hardness testing in a pocket size model and integrated probe. Equipped with its RS 232 interface, it can be switched off automatically. The meter screen shows hardness result, average values and max. value directly.
Standards: DIN53505, ASTMD2240, ISO7619, JISK7215
- Shore A is designed to measure the penetration hardness of rubber, elastomers and other rubber-like substances such as neoprene, silicone, and vinyl. It can also be used for soft plastics, felt, leather and similar materials.
- Shore C is designed for various foam and sponge.
- Shore D is designed for plastics, Formica, Epoxies and Plexiglas.
The theory behind it:
Durometers, like many other hardness tests, measure the depth of an indentation in material created by a given force on a standardized presser foot. This depth is dependent on the hardness of the material, its viscoelastic properties, the shape of the presser foot, and the duration of the test. ASTM D2240 durometers allow for a measurement of the initial hardness, or the indentation hardness after a given period of time. The basic test requires applying the force in a consistent manner, without shock, and measuring the hardness (depth of the indentation). If a timed hardness is desired, force is applied for the required time and then read. The material under test should be a minimum of 6.4 mm (0.25 inches) thick.
Durometers of various common materials
|Automotive tire tread
|Soft wheels of roller skates and skateboard
|Hard wheels of roller skates and skateboard
|Solid truck tires
|Hard hat (typically HDPE)
|Cast urethane plastic
The physics behind ASTM D2240:
Using linear elastic indentation hardness, a relation between the ASTM D2240 hardness and Young's modulus for elastomers has been derived by Gent and by Mix and Alan Jeffrey Giacomin. Gent's relation has the form
where E is Young's modulus in MPa and S is the ASTM D2240 type A hardness.
This relation gives a value of E=∞ at S=100 but departs from experimental data for S<40. Mix and Giacomin derive comparable equations for all 12 scales that are standardized by ASTM D2240.
Another relation that fits the experimental data slightly better is
where erf is the error function, and E is in units of Pa.
A first-order estimate of the relation between ASTM D2240 type D hardness (for a conical indenter with a 15° half-cone angle) and the elastic modulus of the material being tested is
where SD is the ASTM D2240 type D hardness, and E is in MPa.
Another linear relation between the ASTM D2240 hardness value and material elastic modulus has the form
where SA is the ASTM D2240 type A hardness, SD is the ASTM D2240 type D hardness, and E is Young's modulus in MPa.
Main Technical Parameters:
■ Measurement range:0-100HA(HC/HD)
■ Measurement deviation:＜1%H
■ Resolution: 0.1
■ Power supply: 4x1.5V AAA (UM-4) battery
■ Battery indicator: low battery indicator
■ Dimensions: 6.4x2.6x1.5inches (162x65x38mm)
■ Weight (not including probe): 0.38lbs (173g)
■ Ordering information：
CB-15820---Digital Shore A Hardness Meterccal $336
CB-15830---Digital Shore C Hardness Meter $364
CB-15840---Digital Shore D Hardness Meter $392