Writing blogs, especially on technical subjects, is a strange way to make a living. What is even stranger is when blogs start to write themselves. When I started researching and preparing for this blog, my intention was to discuss a new range of vandal resistant switches. With my interest in applications, materials and performance, I was fascinated to understand exactly what 'vandal resistance' actually means in the world of switches.
As we've discussed in previous blogs, we use established standards and ratings as a convenient shorthand to identify how products will perform under certain conditions and to help us choose products for specific applications.
I have been using the IP ratings for much of my professional career to provide my customers with information about how certain connectors will perform, and more recently I have been using the equivalent IK ratings too. In all that time, I had never actually witnessed these tests taking place.
I also felt that it was important to understand the information that IP and IK ratings do not provide as much as the information that they do.
IP ratings are very familiar. They provide very clear information about the conditions under which a product is resistant to the ingress of water, all the way from a light sprinkling to full immersion. However, in order to provide a meaningful comparison, the tests need to be conducted under controlled conditions. It simply isn't good enough to spray your switch with a garden hose or dunk your connector into a bucket. It's just not very scientific.
The use of IK ratings requires the same scientific rigour. These ratings provide an indication of how much impact force a product can resist whilst remaining functional. It is important to remember that this does not guarantee that a device is vandal proof.
At the beginning of March, we visited the UK headquarters of APEM Components, a major manufacturer of switches and indicators.APEM boast a test laboratory to allow them to test their own products. APEM was kind enough to allow us access to their test equipment to see these tests in progress.
However, in the course of the visit and our tests, things did not go according to plan, and taught us more than we had planned to learn!