Simultaneous Cathodic Protection and 4 Wire Resistance Measurement

I am making an electrical resistance sensor for erosion rate measurement using the Arduino. Since my sensing element is a thin strip of carbon steel, I have to ensure that it is protected from corroding, so I can measure pure erosion. I am measuring the resistance using the 4 wire method, and amplifying the potential drop across the sensor using the TLC2652AC chopper-stabilised amplifier; the amplifier gain is 10,000.

I am confused about the cathodic protection part. I plan to use the ADM660 to invert the 5V Vcc from the Arduino, and then use the LM137 negative voltage regulator to produce a negative current of 100 mA, which would pass through the sensor to ground, while I measure the potential drop across it. Since my sensor has an area of 250 mm^2, this would produce a current density of 400 A/m^2.

Is this a feasible way to approach this? Below is a diagram of the circuit.

I'm not sure that using a negative supply instead of a positive one actually gives you cathodic protection. My belief is that you need to have a sacrificial anode that will be corroded in preference to your circuit.

Also I think that you will have stability problems with an op-amp circuit with a gain of 10,000.