Tag-Heppenstall Moisture Meter

[Donk4kyv]

I found this at an antique shop that was going out of business. I paid $15 for it; it was a basket case when I found it; even the wooden enclosure was in pieces. I cleaned it up, re-glued the case back together, and replaced some missing hardware with authentic identical pieces I found in my radio junkbox.

It looks to have been made in the mid to late 1920s due to its similarity in appearance to radio sets of that era. The tube tested good, but I haven't tried to see if it actually works. It needs a no. 6 dry cell and a couple of radio radio B batteries. I have a modern day moisture meter a fraction of its size, so it is more a curiosity to me than something I would actually use.

 

[TheAardvark]

Thats really cool. Never seen anything like that before.

 

[Jags]

Pretty darn cool. I would guess (and its only a guess) that a cabinet or furniture maker might have had something like that back in the day.

 

[Donk4kyv]

I think they all, modern or antique, essentially function as ohmmeters and measure the electrical resistance of the wood. My modern-day handheld meter reads reliably only when I insert the probes into a freshly split piece. I'm not sure why the resistance at the same moisture content wouldn't vary widely according to the species of wood being measured, since the grain and cell structure can be very different.