Tensile machine performance

[ttpolymer]

Dear All,

I am going to purchase a tensile tester for a testing lab. I am quite puzzling in choosing a tester with good performance and high reliability, repeatability and accracy. Would anybody can help me by giving suggestions and comments?
Thanks a lot!

 

[TVP]

Instron makes the best materials testing machines. I suggest you contact someone to discuss your particular needs. Use the following links for more information:

http://www.instron.com/universal_testing/index.asp

http://www.instron.com/universal-hydraulic/index.asp

 

[CoryPad]

I concur with TVP. Instron will be able to help you choose an appropriate model based upon your needs.

 

[PrentP]

The size of the machine depends on what you are going to test - the load cell for testing thin sheet and film will be much smaller than for something as big and strong as gas pipe. Have a look at Lloyd Instruments as well, at

http://www.lloyd-instruments.co.uk/

Regards,

Peter P

 

[Linsey1]

We curreently have an Alpha Technologies T-10 which is an older machine but very reliable. We have recently purchased an Alpha Technologies T2000 which is also good but very pricey. Overall we ar happy with Alpha Technologies equipment and service.

 

[indukurikk]

hi,

MTS corporation also makes tensile testing machines.
check both Instron and MTS.

http://www.mts.com

 

[ttpolymer]

Dear All,

Thanks for your information.
By the way, I heard from my friend that he has encountered problems using Lloyd tenisle machine. When testing the same plastic samples in a resonable specimen size, the modulus is always smaller than others.
I would like to know whether there is any comment since the price of Lloyd fits our budget!
Many thanks.

 

[PrentP]

I have found the Lloyd instument to be reliable. Tell your friend that the only only way that the machine can give a wrong modulus is if the load cell has not been calibrated properly. Tell him to have the cell recalibrated. The only other way is to use the wrong dimensions for the test specimen. Regards,

Peter P

 

[gthelen]

ttpolymer,

Also check out the Tinius Olsen site:

http://www.tiniusolsen.com

they have a wide selection of machines from 225 lbs to 20,000 lbs. Tri-Lingual of course.

They also have a horizontal machine which is extremely accurate, made for high production testing, from low elongation <2% to high elongation >1000% elongation through break and it is an automation ready system.

The BT series machines offer the same accuarcy as the Instron and MTS systems at 2/3 the cost, the ability to use laser extensoemter, high elongation (POGO Stick type Extensometers) and chambers to 600 Deg. F.

Give them a call. 215-675-7100.

GFTHELEN

 

[gthelen]

To PrentP:
The modulus calculation (Delta Stress / Delta Strain) is dependent upon BOTH load and Elongation. If you are using a clip-on extensometer you have to make sure BOTH the LOAD and Strain are calibrated.

If you are using the crosshead position as the elongation device you have to account for the materials slipping out of the grips. If it is a low elongation material, the slip can be a big portion of the total strain and will screw the Modulus.

For high elongation materials, you have to account for the distance between the grips, the problem is with the Dog-Bone cut specimens assume the only place it stretches is in the reduced section, this is wrong and should only be used as a reference. The tab section elongates quite a bit.


To accurately determine the Modulus you have to use a calibrated extensometer for strain measuring and a load cell.

The measurement of the sample is also important the thickness having the most effect on the results.

GFThelen