A storage closet here at Infoblox headquarters in Santa Clara, California, once full of brightly colored holiday decorations, has just been turned into something of a torture chamber for our products – all in the name of ensuring quality and reliability.
We spent $30,000 on soundproofing and retrofitting to make the storeroom ready for a $40,000 thermal chamber from Cincinnati Sub-Zero, a leading manufacturer of environmental testing equipment. The chamber can freeze our products at temperatures as low as -36 degrees Celsius and heat them up to 70 degrees Celsius (minus 33 degrees to 158 degrees Fahrenheit).
We generally test within the normal operating temperature range of 0 to 40 degrees Celsius. To help provide greater reliability by identifying weaknesses and fixing them early, we also occasionally do tests at both higher and lower temperatures.
To meet the requirements of our telecommunications customers, for example, we run tests up to 55 degrees Celsius (131 degrees Fahrenheit). As Vince Hileman, a mechanical and thermal engineer on my team, says, “Carriers need higher uptime. To sell into that market, you have to assume that the customer’s air conditioning might break down over a long weekend and our product has to keep working.”
Extreme temperatures can alter the timing of processors and other components, making them run slightly slower or faster. Even small changes in timing and electrical characteristics can result in a product failure.
When we test products in the thermal chamber, we run not only diagnostic software, but add complex test setups that emulate real-life customer environments and help to avoid flaws in the design. When tests are completed, we do a complete forensic check and pay attention to the smallest details to ensure no failures took place. We also use the chamber environment to test early prototypes and early samples from suppliers to assess their viability and find out the best way to build new products.
While we typically use the chamber for new products, we can also check current products that have problems, to see if failures stem from design or the customer’s environment.
We have always run thermal tests on our products, but we had to use outside testing services. With this new on-site chamber, the hardware team can do more-complex test set-ups, with some tests running three to four days with a steady rise and decrease in temperature. There is already a waiting list to use the chamber.