METHOD AND DEVICE FOR MONITORING LEVEL OF LIQUID IN RESERVOIR Russian patent published in 2012 - IPC G01F23/22 

FIELD: physics.

SUBSTANCE: drop in the level of liquid (10) below the height of a heated thermal element (HT) is determined from the temperature difference (DT) measured between the heated (HT) and the corresponding unheated (UHT) thermal elements placed in the reservoir. According to the invention, the time variation of the temperature difference (DT) is continuously monitored for any significant increase, in particular sudden increase, within a time interval of pre-determined duration (Δt) prior to the respective evaluation time (t₀), wherein an alarm signal is issued as soon as the change (ΔDT) in the temperature difference (DT) within said time interval reaches or exceeds a pre-determined limit value.

EFFECT: in case of considerable complication of the control equipment and system, there is especially reliable initiation of the alarm signal with short actuation time once the monitored liquid level drops below a critical value.

11 cl, 5 dwg