Instrument
calibration is intended to eliminate or reduce bias in an instrument’s
readings over a range for all continuous values. For
this reason liquid level of Lift Sump of sanitary package is shown
in Fig. 12. As it can be seen from 19 July 2013, level of transmitter
was out of service without any fluctuation. Therefore, the effect
of wastewater flow rate on the level of liquid cannot be
investigated.