For spherical tanks equipped with a calibrator. The calibration sensor is installed at the center of the calibrator on the outer wall of the tank. If the calibrator is not installed, the calibration sensor should be installed at the height of the outer radius of the tank (equatorial zone). The calibration sensors for the vertical tank and the process tank are installed on the outer side of the tank body, at a height of 0.5m to 1m from the tank bottom. Note: After installing the calibration tube (calibrator) in the tank, the correct installation position should be marked with paint on the outside of the tank wall in time. Extended reading: ultrasonic level sensor for diesel tank