The most difficult part of the design process was complying with the IEC61010 standards. One of the hardest parts was trying to find an expert in this field to help make sure we were interpreting the standards correctly. Unfortunately, as it turns out this kind of standards expert is very hard to find as multimeter design is a very niche subject.
In the end, we were forced to just figure it out ourselves, which is good because we are now experts in this field. It is a quite difficult standard to wrap your head around because it’s not just for handheld Multimeters, but any test and measurement equipment, so it was a significant challenge just to determine which parts of the standard apply to our product. Moreover, even once that is understood, there are multiple different ways laid out in the standard for making a safety compliant product, determining which one was the best for our product and understanding all the complexities of that approach was also a significant challenge.