Resistance Slider | Pressure Level | Ultrasonic | Radar |
Passive measurement of resistance as a magnetic ring slides up and down a hollow shaft with resistors embedded internally. | Active measurement of pressure in a tank using a silicon wafer that “bends” under pressure and creates a signal. Resultant signal may be voltage, NMEA, CAN or or Bluetooth data. | Active measurement of distance from under a tank (or above tank for Some) to the air-water interface point. Resultant signal may be voltage, NMEA, CAN or or Bluetooth data. | Active measurement of distance from top of tank to air-liquid interface point. Resultant signal may be voltage, NMEA, CAN or or Bluetooth data. |
Above Tank with height access to remove the unit of similar height of tank. | Side of tank as close to bottom as possible. Needs a threaded boss on tank to screw into. | Below tank must use a couplant of grease or glue. Cant have intermediate layer. | Above tank for non-metal tanks can sit directly on top of tank (glue) and for metal tanks, needs hole with SAE 5 bolt pattern. |
20-30mm Accuracy | Varies with quality but typically 20mm | Varies with quality but generally average | High accuracy of 1mm is achievable. |
No active power. Just 2 wire to resistance sensor. | 3 wire of power and voltage value and ground. | 3 wire of power and voltage value and ground or battery Bluetooth. | Battery operate Bluetooth or CAN/NMEA powered 12/24V. |
N/A | N/a | 3-5 years battery life | 5 years Battery Life Enhanced by AI |
Stainless steel components | Stainless steel components | Plastic and embedded sensor | Billet machined Aluminium and embedded liquid proof radar sensor. |
Not Suitable for Black water and troublesome in grey water measurement | Not Suitable for Black water and troublesome in grey water measurement | Not Suitable for Black water and troublesome in grey water measurement | Perfect for black water, grey water even with foam on top. |