KOBUNSHI KEIKI CO., LTD.
 



Micro Duro Meter
HARDNESS TESTERS
 

Model F

Urethane Foam
Sponge
Non-woven Fabric

Model PF

Powder Puff

Exclusive type for foam materials, allowing measurement by placing the tester on the object of measurement. In addition to Model F, Model FP is available for powder puff.


Model C  &   Model C2

Soft Rubber
Urethane Rubber
Sponge
Wound threads(yarn package)
Rolled Films
Potter's Clay(Kaolin)

Model C is intended for hardness measurement of Soft Rubber, sponge, foamed elastomers, wound threads(yarn package), rolled films, potter's clay(kaolin) and other such soft materials.
For even softer materials, Model C2 is available.


Model CS

Polystyrene Foam

This features larger indentor and a more strong spring compared to Model C, thereby making it more suitable for polystyrene foam.


Model A

Rubber in general
Softer plastics

Has been used for wide applications since being standardized in the ISO.


Model JA

Rubber in general
Softer plastics

A hardness tester which conforms with the Japanese Industrial Standards JIS K 6301. One of the most popular types in Japan, but has recently been gradually replaced with the ISO-specified Type A.


Model JAL

Rubber in general (Specially for measurement of recessed surfaces)

Especially useful for recessed and/or smaller measurement areas. In addition to the standard Model JAL, long presser foot type are available for another Model applications.


Model B

Semi-rigid Rubber
Unglazed pottery clay

It uses the same spring load used in Model A. It adopts a conical indentor similar to that of Model D, so as to be applicable to harder measuring objects than can be measured by Model A. It is useful for hardness measurement of unglazed pottery clay and ceramics in green condition.


Model JC

Semi-rigid Rubber

Model JC has those hardness testers described in JIS K 6301 as 'suitable for samples found to have a hardness value above 70 according to Model A'. It features higher resolution for hardness measurement of hard rubber.


Model D

Hard Rubber
Plastics

Similar to Model A, this model is defined as 'Durometer Type D' as described in various domestic and international standards. It is in widespread use for hardness measurement of plastics and hard rubber.



Model Principal
Standards		 Indentor Design Spring Load [g] Size & Shape of Presser Foot [mm] Outside Dimension [mm] Weight [gr]
Height
[mm]		 Shape 0 Degree 100 Degree
JA

JIS K 6301
(Type A)

2.54 35-Degree. Truncated Cone 0.79 55 855 44 x 18 (rectangular) Width 57
Depth 30
Height 76		 200
JC

JIS K 301
(type C)

100 4,500
A

JIS K 6253
JIS K 7215
ASTM D 2240
ISO 7619
ISO 868
(Durometer Type-A)

2.50 56 821
D

JIS K6253
JIS K 7215
ASTM D 2240
ISO 7619
ISO 868
(Durometer Type-D)

30 Degree Cone Tip Radius 0.1 0 4,533
B

ASTM D 2240 (Durometer Type-B)

56 821
ASKER C

SRIS 0101
(SRIS: Society of Rubber Ind., Japanese Standard)

2.54 5.08 dia. Hemisphere 55 855
ASKER C2

ASKER C2

55 455
ASKER CS

ASKER CS

10 dia. Circular Cylinder

100 4,500 50 dia. (Circular) 50 x 50 x 76 200
ASKER FP

ASKER FP

15 dia. Circular Cylinder 100 200 50 x 37 (Oval) 50 x 37 x 81 300
ASKER F

ASKER F

25.2 dia. Circular Cylinder 55 455 80 dia. (Circular) 80 x 80 x 81 500


Indentor Design  
Conical Design

Cone point type.
Model D and B have this type.
Measuring object: Hard Rubber and Plastics.
Truncated Cone Design

Flat point type.
Model A and JA have this type.
Measuring object: Rubber in general.
Hemispherical Design

Hemispherical point featuring larger contact area.
Asker Model C is included in this type.
Measuring objects: Soft rubber and sponge rubber.
Cylindrical Design

This type allows an extended specimen surface area to be pushed.
Models F, FP and CS have this type.
Measuring objects: Urethane foam, sponge and polystyrene foam.


Long Presser Foot Type

This features a longer presser foot. allowing measurement of narrow measurement objects of those having recessed sections.

Models JAL and JCL

dia. 10 mm

Models AL, D and BL

dia. 12 mm

Models C1L and C2L

dia. 16 mm



Load Tester for Hardness Tester

A load tester to check the characteristics of spring loads applied by hardness testers. With the force of weights it applies a specified reference load onto the indentor to check for correct correspondence between hardness reading of 25, 50, and 75 and relative spring loads. Different types of hardness testers provide different spring loads. Refer to the table below for selection o( the optimum type. .

  Testing
Load (g)		 Applicable
Hardness Tester		 Virtually applicable
Hardness Tester
    Model Reference
reading		 Model Reference
Reading

For Model
JA & C

255

JA
(JAL)
C		 25(25.5) A
B		 26.0

455

50(50.5) 52.1

655

75(75.5) 78.2

For model D

1134

D 25 JC
CS		 23.5

2267

50 49.3

3400

75 75.0

Indentor Extension Tester for Hardness Testers


A gage to check the extension of an indentor on a hardness tester and the reading indicator mechanism. Applicable standards specify two extension, 2,54mm and 2.50mm for an indentor and the indentor testers are available for two models JA and A corresponding to the respective extension. Each indentor extension tester set is complete with two gages, one for hardness value of 50 and the other for hardness value of 2.
 

Hardness Measurement using Constant Loader for Durometer


When attempting to measure hardness manually, inconsistent pressures and/or speeds are used while pressing the indentor and presser foot. This causes a problem of deviation in measured results, To solve this problem, CL-150 Series constant pressure/speed loaders have been developed. Applicable standards refer to this type of loader as a 'Durometer Holder.'