Instead of force, maybe voluntary? Publish/promote a set of standard measurements for consumers, then let consumers drive the manufacturers. "The Market" will follow the consumer if the consumer is strongly inclined about its desires - I think we have seen this play out in other consumer electronics niches...

When I was a teen, I wanted an alligator on my shirt, and not too long after I started seeing simulacra shirts... Enough of a demand for more than one entity to mimic it...