I think many unexperienced fuel level sensors users make an error mixing two different processes - calibration of sensor and calibration of tank. And answer from manufacturer in fact not correct.
Calibration of sensor - it is an easy procedure to improve sensor range a bit after cutting. It can be automatic or not. Anyway, it takes about 5 minutes.
And calibration of tank is needed to recalculate level data to volume data. Basically during this process sensor (or wialon) is teached by tank shape. You can never find a sensor with such "autocalibration". if tank shape is strictly rectangular you can skip it but in most cases you have to make this procedure.
Датчики расхода и уровня топлива, системы бортового взвешивания, контроля температуры и другое оборудование для телематики
Manufacturer of fuel level/consumption sensors, onboard weighing, temperature sensors, displays.... etc.eurosenstelematics.com
telegram channel (ENG) https://t.me/eurosens