We found this circuit in a Poptronics from the 90's. Equivalent operational amplifiers can be used. The circuit must be supplied by a symmetrical source.
This circuit is from a 1965 Motorola documentation. The transistors are of the time as is the...
This circuit measures the conductivity of a saline solution, which is affected by the electrolysis effect....
March 2017 - Coilcraft SLR series inductors for currents up to 100 A can be obtained from Mouser...