Relative Humidity Sensor Digitizer-Charge Pump Based

Hygrometer Digitizer Has 0.3% Accuracy, Although Sensor Must Float Off-Ground. Humidity Sensor Determines Charge Delivered to A1 Integrator During Each Charge Pump Cycle. Resultant A1 Output Ramp Is Reset by Level Triggered C1 via Q1. Output Frequency, Taken at C1, Varies with Humidity