Since Adams is an extremely common name, and Ansel Adams is the face of photography and exposure, trying to find background on this meter by searching on its name is an excercise in futility.

This appears to be an American import of a Japanese meter. I've never heard of it and it doesn't appear in my (albiet spotty) lists from that period, and I haven't seen any adveritsing or references to it in my magazines.

One fun thing about this, however: they had the decency to brand the actual maker's name on the back: Kuwano Electrical Instrument. They appear to be still in business: a maker of electrical meters. They seem to have the typical corporate myopia about their own history. You can click on the link for "history" and then on the photo of the meters, you get a corporate timeline. (This version goes through Google translator into English.) If you look at it, it appears that they began business in 1904, and then absolutely nothing happened until 1950.