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|For Natural and Synthetic Rubber, Elastomers and Polymers|
PTC's new Half Point™ Durometer has a total accuracy of ± 1/2 point for the most stringent material testing. By closely following ASTMD2240 test methods, the Half Point Durometer can significantly improve durometer hardness readings and repeatability.
The significant advances in polymers which are materials with characteristic mechanical and physical properties controlled by the structure and the method synthesis make this certified durometer the ultimate working lab durometer.
Polymers are substances whose molecules have high molar masses and are composed of a large number of repeating units. There are both naturally occurring and synthetic polymers. Among naturally occurring polymers are proteins, starches, cellulose, and latex. Synthetic polymers are produced commercially on a very large scale and have a wide range of properties and uses.
The durometer can be used either with a test stand, hand-held or with the constant load weight. Please refer to the stand selection guide for the appropriate accessories. The PTC® Half Point Durometer comes complete with A2LA/NIST Certification, carrying case, test block and magnetic max hand.
|Specifications & Dimensions|
|Specifications||Half Point™ Durometer 306L.5|
|Accuracy||± 1/2 point|
|Max Hand||Magnetic Max Hand|
|Display||Dial Gauge 240°|
|Gauge Features||Reads Zero at Rest|
|Base Size||1.625" x 1" ( 4.13cm x 2.54cm )|
|Height||4" ( 10.2cm )|
|Width||2.25" ( 5.7cm )|
|Depth (Indicator)||1.75" ( 4.4cm )|
|Weight||8 oz.( 227g )|
|Certification included||NIST Traceable/A2LA Accredited|
|Accessories||Test Stand Model 471 or 472|
|Meets or Exceeds||ASTM D2240, ISO 868|
The Model 472
|1kg Deadweight Test Stand||Model 471|
|Constaloader Automatic Test Stand||Model 472|
|1kg Load Weight||Model 441|
|Test Method per ASTM|
|The test method employed is as important as the durometer used for testing your precision materials such as medical and aerospace polymers.
The following procedures are based on ASTM Standard D2240. This standard is recognized as being definitive, however, not all applications require such stringent controls.
The surface of the sample to be tested shall be clean and smooth. The sample should be at least 1/4" (6 mm) in thickness unless it is known that identical results are obtained with a thinner specimen. Thinner materials can be stacked to obtain the minimum thickness. The sample should be large enough so that the indenter is at least 1/2" (12 mm) from any edge unless it is known that identical results are obtained when measurements are made closer to the edge. The surface of the specimen shall be flat over a sufficient area to permit the presser foot to contact the specimen over an area having a radius of at least 1/4" (6 mm) from the indenter point. The temperature of the specimen should be 73.4°F ±3.5°F (23°C ±2°C). The specimen should be allowed to rest at this temperature for at least 1 hour prior to testing, as the properties of most materials change with temperature.
Place the specimen on a hard, horizontal surface. Set the ancillary hand of the durometer below 5 points on the dial. Hold the durometer vertically with the point of the indenter at least 1/2" (12 mm) from any edge. Apply the presser foot to the specimen as rapidly as possible, without shock, keeping the foot parallel to the surface of the specimen. Apply just sufficient force to obtain firm contact between the presser foot and the specimen. Hold for 1 or 2 seconds, the maximum reading can be obtained from the ancillary hand. If other than a maximum reading is needed, hold the durometer in place without motion and obtain the reading after the required time interval. PTC recommends the use of the Constaloader Test Stand for timed readings. Make 5 tests at least 1/4" (6 mm) apart and use the average value.