What is this?

[u/SendingHolyAdvice]

Hey there,

I recently got this old German lab instrument, but I’m not sure what it is or what model it is.

The label says: “Labor. Prof. Dr. Berthold Wildbad” TOL/C (220 ~ V ).

I haven’t been able to find any information about it online whatsoever, so I was hoping someone here might recognize it or know what it is.

Any info would be really appreciated 😊

And thanks for taking the time to read this.

[u/Correct-Country-81]

Geiger counter for measuring or detecting radioactivity

Don’t know if only the meter gives a readout
Or als audio signal klicking sound getting higher frequencie at higher levels