Daily Table Tennis Chit Chat

[Archosaurus]

I'm much more inclined to think your measurement is wrong than the manufacturer, because Shore A 23.5 would make Tenergy somewhere around 33 ESN, and that's obviously not the case.

Scales are not directly comparable on nonlinear elastomers. Even on Chinese rubber the methodology doesn't add up, and a 40A sponge can measure 40A but measure anywhere from 49 to 55 O typically.

Dignics sponge measures 46 and is reported as a 40, so with the less progressive Tenergy sponge, at 36 hardness, I would not be surprised if it's closer to 40. Eventually I'll get a Tenergy 05 sheet for myself and just post numbers.

FWIW my measurement doesn't differ more than 1deg from what ESN claims for their products. My Europe Vega DF for example measured 37.3 - 37.5, with a claimed hardness of 37.5. Nittaku rubbers also measure exactly. So I don't think my durometer is miscalibrated.

Bear in mind that if you press the durometer into the sponge, it will measure harder artificially. You just need to sink the needle.

 

[jonol]

Well, you can post whatever numbers you like but I can assure you that no one is going to believe you that Tenergy is 23.5 Shore A/33 ESN, a full 14.5 degrees less than Fastarc G1 - and 12.5 degrees lower than Butterfly's rating.

Your readings are clearly not consistent, if not entirely wrong.

 

[Archosaurus]

Well, you can post whatever numbers you like but I can assure you that no one is going to believe you that Tenergy is 33 ESN, a full 14.5 degrees less than Fastarc G1.

Your readings are clearly not consistent, if not entirely wrong.

Tenergy is not 33 Shore O because that's not how this works at all. The only time you can compare scales is when you're measuring a rubber brick that has no progression whatsoever. These 2mm thick elastomers with complex air cavity geometry are really far from that. Especially Spring Sponge. To get an idea you'd need to measure it with at least 3 scales which sink to different depths, then test with other models as a control.

EDIT: And if the scales have different indenter head shapes and thus different contact pressure, it's not comparable anyway. A and O differ. To get an actual accurate measurement, you'd need to change the spring without changing the head. As per ASTM D2240 the maximal spring force is 8.065N although the actual contact pressure differs, I think O is 12N while I don't remember A.

Fastarc G-1 is 47 - 47.5 O.
Tenergy 05 Hard is 29.5 A.
Dignics 09C Commercial is 32.5 A.
Dignics 09C JNT is 34.0 A.
Dignics 80* Commercial is 46.0 O.
Dignics 05 CNT is 32.5 A.