Field strength meter
The unit discussed here indicates, by means of achain of LEDs, in logarithmic ratios the strength of an electric field surrounding the unit. The input signal across theconducting discs is applied to the non-inverting input of IC. The amplification of IC1, A=R4/P1. In the prototype P1 was set at about 210 kΩ to give an amplification of about x50.