Getting warmer

commentary Although we mainly stick to technology testing, occasionally we find ourselves doing something completely off the wall.We are often asked to test some pretty strange stuff here at the Lab and while we have the acronym "IT" in our title people tend to skip this and focus straight on "Test Lab".



commentary Although we mainly stick to technology testing, occasionally we find ourselves doing something completely off the wall.

We are often asked to test some pretty strange stuff here at the Lab and while we have the acronym "IT" in our title people tend to skip this and focus straight on "Test Lab". So quite often we are asked can we test concrete for strength, Zimmer frames for compliance, fabric for colour fastness, or floor tiles for wear performance, just to name a few.

But every now and again we are asked to test an item that may or may not fit our core IT business, but for one reason or another -- maybe we like the challenge or simply say why the hell not -- we agree to test.

Inevitably this results in the need for new test procedures to be developed and more often than not a new test rig to be designed and constructed. The Lab does not have a huge R&D budget to develop test equipment and so we often have to think a little outside of the square to come up with solutions that we can knock together. Often this results in some pretty novel looking machinery.

You may be fascinated to learn that in this day and age of electronic sensors the humidistat's relay is opened and closed by strands of human hair.
Our first foray into this field was quite a few years back when a corporate client asked us if we could test a new connector for an EFTPOS device. The problem was that the wires in the connector were fatiguing after the repeated "tugging" on the cable by customers using the device. A new plug was developed, but no one could prove that it actually was better. So we developed a rig that connected the cable to a notebook's serial port to detect any breaks in the cable/connector continuity. The rig itself was constructed from a sheet of timber, a 12v windscreen wiper motor, a DC power supply, a collection of springs, and an old CD. The CD was used to prevent the cable and springs binding with the wiper motor drive unit.

One of my personal favourites came about when we were asked if we could simulate the temperature and humidity conditions of Australia's far North and gauge the effects on systems and their components. Apparently it's not uncommon for PCs to fail in hot and humid environments like Cairns or Darwin. Luckily we were halfway there with this one as we had previously constructed a thermostatically controlled oven to "cook" PCs, servers, and notebooks. So all that remained was for us to develop a way to humidify the oven. We came up with a design that used the following materials: a powerful exhaust fan, an insulated central heating duct, a large plastic container, a pond pump, a home-made trickle feed, an evaporative air conditioner core, and a humidistat.

You may be fascinated to learn that in this day and age of electronic sensors the humidistat's relay is opened and closed by strands of human hair. A hair expands and contracts in a precise and reproducible way depending on the humidity content of the air, and by simply adjusting the tension on the hair with a small cam arrangement you can set the device to operate at a specific humidity level between 10 percent and 90 percent.

Initially, what is essentially an evaporative air conditioner does cool the oven, but it is a sealed system so as the air becomes more moisture laden, the cooling effect dies and the PC equipment inside soon reaches 40 degrees and 80 percent humidity levels, or your average nice day in Darwin.

Our latest project is to test pens for a manufacturer in terms of their writing performance, and so once again we have embarked on creating a test rig that feeds paper past a pen tip at a constant speed of five metres per minute while the tip of the pen is held on the paper at constant pressure ranging from 100g to 200g depending on the test. Initial testing has also shown that the pens can write for many hundreds of metres so we are going to have quite a pile of used paper rolls when we are finished and the testing is going to take a long, long time.

Steve Turvey is Lab Manager of the RMIT IT Test Labs, and can be reached at stevet@rmit.edu.au.

This article was first published in Technology & Business magazine.
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