WPG-2 (90 Ω increasing). Resistance equals 0 Ω with an empty and 90 Ω with a full gastank. WPG-4 (50 kΩ decreasing) Linear characteristic. Resistance equals 50 kΩ with an empty and 0 Ω with a full gas tank. WPGH-1 Non-contact (Hall sensor) gas level indicator with a linear voltage output. Voltage equals 0V with an empty and 5 V with a full gas tank.