The Testing Times

Used for testing reinforcing bars or reinforcement bar ( Rebar ) for the construction industry. The way that mass produced R ebar is made requires test for consistency throughout a products manufacture life cycle. The sample is placed on the lower support rollers, then bent to a certain angle (depending upon test). It is then treated (heated to a specific temprature) and then rebent, back to straight and an observations are taken.

This attachment is used to test the strength of the welds that hold mesh together. The mesh is often used as a reinforcement for concrete structures. as this is a structural component it is essential to test the consistency of the weld in any given section. A joint is cut from the mesh and placed in this attachment. A grip, the HW 14 is then placed on the end of the rod. a force of up to 50 kN is then applied and the shear strength of the weld measured. There is some adjustment in the design with a sliding plate that allows for different gauges of wire. The applicable standards are: BS4483, ASTM A185, ASTM A497 and ASTM A974. The testing application note for this grip is available from the resource area of our School of testing microsite or by clicking here .

I'm afraid that I've brought a bit of a bug to Tinius Olsen... Everyone seems to be developing blogs. (I think you can get a cream for it from a good pharmacist). If you want to learn about testing plastics, try this. http://www.testingplastics.com/ If you'd like to learn about testing metals, try this. http://www.testingmetal.com/ If you are a student looking for testing advice or examples try this. http://www.schooloftesting.com/ And of course testing textiles can be found here... http://www.testingtextiles.com/ Harry, Earl, David and Sylvia are all specialists in their specific areas and are happy to help... The question and answers section is very informative.

This a ttachment , the S0991 is designed to test how card and paper folds, a small sample section is taken and placed under a retaining bar, this is then forced to fold using the fold bar at the back. A rotary digital encoder measures the rotation angle and compares it to the force measured on the loadcell . To ensure self-alignment cord is used to rotate the pulleys that move the folding bar. Used in the packaging industry this compares how easy is is to open your box of cereal in the morning and to see how strong the folds are...

BS4370-2:1993 Method 9 tests the tensile strength of rigid Cellular Material. This encompasses things like ridged foams used for padding and floatation devices. Method nine calls for two different profiles of the sample material to be cut. To save on having two different rigs, this one device can accept both sizes of sample. it also has interchangeable and modular test face profiles.

It's sometimes necessary to attach a grip or fitting that has no way of self aligning , in these cases we've developed several ingenious ways to add this function to the machines. One of these methods is to use a Self- Aligning Fixture like the one shown in the picture. As it is designed to fit a 150 kN U-Series machine it is somewhat massive. The top thread being 1" UNF in diameter and the bottom an M33. It weighs, a not insignificant , 7kg; has a 110mm body diameter and is nearly a foot tall. The central pin that you can see has is supported by a Nitrile block which allows it to float, whilst absorbing the shock of a sample failure.

The Compression of a spring can be quite a hard thing to measure, the spring has a tendency to want to exert it's applied force horizontally to the platens (in other words, fly off under the nearest table...) This isn't really a problem, just a nuisance and in some applications a desirable feature of springs... To stop the test sample from flying off these compression platens have a free running guide that retracts into the top body. This holds onto the spring, whilst having a known affect on the test.

All of the testing grips and attachments listed here have a specific use. For example the Insulation Grip is designed to be used with insulation materials, but it can equally work just as well with any fibrous material. We often review or re-use previous designs because we know that they work and have been proved to be successful in the field. The staff here have an encyclopedic knowledge of over 2,000 Bespoke products and custom test fixtures we've produced over the years, and are continuing to produce on a daily basis. Basically, if you need to test something, and you require help call Tinius Olsen ...

To improve usability we have extended the range of insulation grips to include a screw based closing mechanism. This gives the ability to close the grip like a vice and so you are relying on the mechanical advantage provided by the screw rather than by the lever, this can offer more control of the sample alignment and help prevent a jaw break... There are interchangable teeth, depending on requirements.

The ASTM D429-03 69.1 (Method G) is for testing the adhesion properties of rubber. The rubber is pre-formed onto 3 metal plugs. this gives a double rubber sandwich that can then be tested. This attachment holds the metal components of the sandwich and allows a double shear test to be performed.

A range of faces make the 123-001 Textile Grip an adaptable and very useful attachment. Textiles can be a very hard materials to test, they can be very strong in tension, and unless ripped, near impossible to break… it can hold large amounts of energy and can break with a bang! The grips that hold fabric tend to be hydraulic and have special grip arrangements because of this property. There are 3 types of face of the jaws. Plain, Hatched and Grab each have a specific set of materials that they can be used with, each with singular benefits. The 123-001 holds the sample between two 250mm wide faces, these come together with a clamping force and the test can then be performed. If you're interested in this or other Textile testing, please contact Sylvia Hillier or go here: http://www.testingtextiles.com/

As mentioned before, we do a wide range of platens (two parallel plates that are used to compress the test specimen...) Often the sample is uneven or has protruding features, the fixed platens are less effectual in this instance. In cases like this, self aligning platens distribute the load across the sample by increasing the contact area. (The arrows show movement...)

It's really nice to be able to show you some pictures of the finished products, rather than renderings. The attachments, once checked, go straight to the customer... (so we don't often get time for pictures). This test is for Bituminous Materials, like tar -or- polymer modified asphalt (depending on you professional inclinations). The ASTM Standard calls for a very precise procedure that includes warming and filling a 3oz. pot with the sample and lowering a semi-sphere into it. This is then extracted and the forces required measured... It's quite a demanding test for the equipment as the sample material is quite, well, sticky... so we've made the parts that would come in contact with the sample out of stainless steel, this should allow the parts to be cleaned without having to worry about affecting any surface finish.

This attachment consists of a bath and holder to test the tension applied to a section of artificial skin. The sample is tiny, only 0.508 mm in section. The sensitivity of the system allows for small samples to be tested. Testing Artificial Skin has some unique requirements, the sample needs to be kept moist, in this case there is a simple saline bath. The sample is lowered into the bath and then can be tested...

This attachment simply pulls nails and staples from wood, as you could imagine it is very important to know and understand the way in which fixings behave in wood. As wood is a natural substance each plank is different from the next, and it is the job of BS EN 1382:1999 to ensure that fixings (nails and staples in this case) that are a known quantity behave the same way in different kinds of wood (nails and staples are produced on mass and so are quantifiable). There are two attachments, one for nails and one for staples. It can hold a variety of nails and staples due to the taper on the attachments. The lower component holds the wood, it is common with ASTM D1037 & D1761 Standards which are similar wood tests.

We've been thinking, there are lots of great resources and information regarding testing machines and attachments, but we don't want to put them all on here. It might get a little cluttered... Our colleagues at Tinius Olsen have put together a good list of resources on the Tinius Olsen Homepage. The direct link to the list can be found here

830-001 ASTM D2519-02 Electrical Insulating Varnish The ASTM standards (sometimes) give accurate and very precise instructions on how a specific test should be performed. This is an example of one of these tests, the parts and method are explicitly layed out within the standard document. This attachment uses a 3 point bend applied to a coil to test the strength of Electrical Insulating Varnish. The coil, made from various metals, are wrapped tightly around an anvil. The anvil is then removed and the coil placed in the varnish solution. The coated coil is then placed in this 3-point bend and then tested. This is then used to show the properties of the varnish when applied to the metal. As this test uses the appropriate materials in an accurate situation it should produce good results.

W e often come across the problem of testing the strength of fixing methods like adhesives. But how do you test the finished product once the product is produced? Increasingly credit and debit cards have small microchips on them. These are generically called 'Smart Cards' as they contain a great deal of information on the 'chip. To test the strength of these cards, in particular the bonding strength, this attachment has been developed. It is adjustable so that the 'chip can be tested wherever it is placed on the card. There is a retaining arm that is used to hold the card in place, this has a roller on the bottom that allows quick changes. There is a specific routine that allows the chip to be pushed through and the force required is measured...

We sometimes need a little help to get things off the ground... For safetys sake, it's worth hiring the correct equipment to move Tinius Olsen machines around. This is one of our machines being moved into our Demo Suite, which happens to be upstairs!

A Luer fitting is the common name for a tapered fitting that adheres to ISO 594. In this case it was necessary to hold a needle which had a Luer attachment on it. this was to be used for puncture testing, so no thread was required. Used as in conjunction with S0994, this test used a range of standard needles with Luer ends. This simple needle or luer attachment could be used for any number of compression, puncture tests on components with Luer ends.

This Grip is used to test the bodies of Sharps Containers. As you might imagine, it is very important that 'sharps' cannot penetrate the sides of the container. This grip is used to hold a fine needle in one end, and a sample of the moulded box the other. There is a piece of foil underneath the specimen , this allows the system to know when the needle has punctured right through. An accurate measurement of the force required is then taken. The needle holder rotates allowing the user to insert the needle without bending over or risking hurting themselves with the needle. The base is a simple stand with hole, the connection to the foil is made with a clip.

These grips are used to test seat belts and webbing up to 100mm thick. seat belts have interesting properties, they have to cushion the shock of a crash without injuring the passenger of the car at low speed stops. In a collision it has a precise elastic limit, meaning that it stretching slightly to diffuse the shock, goes beyond its elastic limit, becomes plastic then holding it's passenger without breaking, there is a great deal of force involved in this process (which is why these grips are rated to 100 kN ...) The testing can be quite explosive as the belt stores a great deal of energy before failing. By exerting a tensile force on the belt it is possible to see how it will behave. One of the important features of this grip is that it is self tightening. The specimen is feed through the grips in a specific manner as not to damage the belt. A damaged belt can dramatically affect its ability to protect the passenger, and once it has been stretched to it's elastic limit and ...

This grip is designed to meet the very strict guidelines set within the ASTM D143 standard. I have mentioned this standard before, it is one of the most demanding standards available for wood specimens. One of the most important tests when it comes to the structure of wood is how it reacts in tension. As wood can be very strong in tension it's is necessary to 'profile' the sample (cut the wood into a specific shape) so that the region undergoing test is uniform, in the middle and weaker than the grip or piece of wood the grip is holding onto. It also needs to be smaller to allow an extensometer to be added to measure the small changes in the length of the sample. This grip is essentially self-aligning, the sample slotting into the two fingers.

Articulated 4 Point Bend Test for Ceramic Samples. Used for testing the smallest ceramic samples 1.5mm x 2.0mm x 20mm. The test calls for articulated anvils that are free to move as the sample deforms. The problem is how to hold the anvils in place before loading the sample. The answer is it’s all done by magnets. The anvil is attracted towards the end of the bar magnet. The magnets are positioned so that the anvil will return to the start position as soon as load is removed. In case you loose the odd one, we supply a bag of spares!

A flexural test tells the tester how much force a specimen can withstand in the middle when supported at a distance (or its flexibility!). This test supports the specimen between two loose fitting ‘rollers’, the distance apart of which can be set for a specific test or specimen size. Once the sample is in place the anvil can be brought down just above the specimen. A variety of tests can then be performed. The specimen can be flexed a certain number of times to judge it’s elasticity or plasticity over a given time. The specimen could be flexed until it breaks, it could be flexed for a specific time and the responding force measured. This is a Heavy Duty system, which has been designed to suite the U-Series 100 kN System . It has a travel of 400mm from centre (800mm overall) and Ø10mm rollers. This can all be recorded in the software and multiple specimens can be tested.

Sylvia Hillier, the Textiles expert here at Tinius Olsen has her own blog, she is very knowledgable and a really nice person to boot! If you've got any textile related issues go here! http://www.testingtextiles.com/sylviablog.php

Some of the more destructive tests that our systems are designed to perform can be quite violent, the forces and materials used can have some explosive results. It is often important to guard the rest of the room or the user from flying shrapnel. We produce guards for these reasons, as the U-Series is over 2 metres tall and a large footprint; the U-Series needs to have a huge guard. We made the guard a close rectangular fit around the system; it is free standing although there are some mounting points to attach it to the system. aluminium section and composite sheet make the frame up, which is a very strong (and heavy) structure. It has two wrap around doors and polycarbonate windows that allow the user to see and control the test. For safety the control unit and an emergency stop have been placed on the right hand door. I can safely say that this is verging on architecture, rather than engineering!

Imagine trying to hold a piece of fibre insulation (the stuff in your roof that stops the heat escaping) in a clamp and then pulling it apart using a tensile test, how on earth do you do it? It’s fibrous, comes in different thicknesses, breaks of easily into chunks… Well the answer is Nails, and lots of them. This is the most effective way to distribute the load across and through this particular sample, this means that the test specimen isn’t overly damaged when you grip it. If the sample is ‘waisted’ properly (like an hour glass), it will break in the weakest spot, not by the grip. This is a technique used time and again with all kinds of samples. You want to see how the material will break under load, not how the grip breaks it, and then the load pull it apart. As there are a lot of nails it’s quite hard to push them through the top surface of the specimen (Imagine trying to nail 20 nails at once into something soft. It might be soft but there is a lot of friction to overcome). To ...

The Standard ASTM D143 outlines several methods for testing wood. As a building material it is essential to understand the structural integrity of timber this is what ASTM D143 is designed to find out… This is a heavy duty application (wood is an interesting substance in compressing and the jaws can get ‘gummed-up’ with the wood sap) and so for this particular application a Tinius Olsen H75KS system is used. The S0971 is designed to perform one of the tests in the ASTM D143 stable. It shears the wood between two vertically offset, horizontally parallel faces. This system uses a self adjusting blade to shear the sample against another supporting blade that is offset 3mm from the main cutting face. This distance can be adjusted using a simple shim. This simple modification could allow for future testing in these standards... ASTM D 143-94, ASTM D 905-98, ISO 6238 2001, JIS K 6802-1973, JIS Z 2117-1977, BS 373: 1957 and JAS 601-1974 testing standards. Features: This system uses a qui...

The Tinius Olsen S0616 is used to hold a standard syringe for testing fittings. It makes use of the end of the syringe, whilst holding it in place. The plunger cannot be used whilst in this grip; this is a method of testing the end fittings not the syringe. There are a variety of fittings that attach to a standard syringe, the most common of which is a standard Luer fitting. We do a few grips to hold Luer fittings, but it’s sometimes just as easy to hold the syringe and use that as the ‘grip’ end. The materials are correct, syringes are cheap, and it’s a real world test. If there is any damage to the syringe it can be easily replaced…

From the same stable as the S0984 this grip uses similar materials but holds the specimen in a different way. Designed to meet GOST23785 it is designed around the drawings given in the standards. The cord is wrapped around the Spiral Ebonite Bollards and held in place with a simple screw grip… This effectively distributes the load over a wider area on the cord. This means that delicate or multi-strand samples can be tested. One of the main problems with testing cord is the grips can create weak points in the sample if it pinches or nips the sample. This results in the test being void or can give misleading results. This grip is designed to avoid this... It has a 5/8" Nosepiece which means that it would fit on one of the smaller systems.

At first sight, one of less intricate but useful tests is compression tests. This is basically applying a force (measured in Newton’s) to the sample and measuring the effect the force has. There are a wide range of tools for doing this but in general platens are used to hold the sample and apply the force. Platens are large flat surfaces that can be used to compress a sample… The S0404 platens are big, very big. They fit on the 100 kN U-series Systems (they can apply a force of 100 kN to an object) Tinius Olsen produce… These behemoth platens are 350mm x 350mm and 35mm thick plough ground plate. I’m a big chap and I can’t lift one on my own… A brute force approach, but the feedback received through the Loadcell and Compressometer is very precise and can show how much force a sample can take and spring back or fail. The results gleaned from these tests can tell a great deal about the product under test, the 'intelligence' comes in the form of the Software, which can be use...

S0844 Tinius Olsen GOST 23785-1 Cord Grips The Russian Standards are called GOST , and we've recently had a few of these come through the doors. This grip is designed to meet the GOST 23785-1, they are designed for testing cord. Interestingly the GOST standard calls for Vulcanite to be used as the grip faces, a difficult material to machine but can be used to great affect. This grip simply holds the sample in a vice grip after being wrapped around the testing face. ГОСТ 23785.1-2001

Used on some of our smaller systems, the S0981 Tinius Olsen ASTM C736-00 Adhesion Test For Latex Sealants, quite a recent one, this grip design is used to test the strength of sealants and adhesives used in the production of windows. It's quite a complex process to prepare the samples, using a c shaped 'mold' the sealant is injected between a glass and aluminium plate. These are held together using (good ol ') G-clamps. It is then allowed to cure for a specific time... as it's nice to prepare a few of these samples to test, we provided a few kits (C section, and the aluminium and glass plates). It was odd, as you had to remember that the test specimen was a liquid that needed to cure, in a mold. I was something that I had to keep reminding myself. This test allows you to find the Adhesion strength of the Sealant between the desired structural material types. In this case glass and aluminium.

The 4 souls and I in the Design Department thought that the wider world might be a little interested in the projects that we engineer and the interesting and varied products that Tinius Olsen produces... There is plenty of time at lunchtimes to do this... and it's a healthy reminder of the projects we've done in the past...