Abstract: A system comprising: a reservoir (14) for holding a liquid; a pump (20) arranged to pump the liquid out of the reservoir (14) or into the reservoir (14); a level sensor (26) configured to detect the level of the liquid in the reservoir (14) and to generate level data; a current monitor (28) configured to monitor the current drawn by the pump (20) and to generate current data; and a controller (30) configured to: receive level data and determine the static head from the level data, and generate head data from the static head; receive first current and head data corresponding to the current drawn by the pump (20) as a function of the static head for a first period of operation of the pump (20); receive second current and head data corresponding to the current drawn by the pump (20) as a function of the static head for a second period of operation of the pump (20), wherein the second current and head data is recorded when the liquid in the reservoir (14) is between a first liquid level and a second liquid level,

Abstract: A system comprising: a reservoir (14) for holding a liquid (1); a pump (20) arranged to pump the liquid (1) out of the reservoir (14) to a system outlet (24) or into the reservoir (14) from a system inlet; a pressure sensor (34) arranged between the reservoir (14) and the system outlet (24) or between the system inlet and the reservoir (14), the pressure sensor (34) configured to measure the discharge pressure (Pd) of the pump (20) and to generate discharge pressure data; a level sensor (26) configured to detect the level (1) of the liquid (1) in the reservoir (14) and to generate level data; a power monitor (28) configured to monitor the power consumed (p) by the pump (20) and to generate power data; a volume monitor configured to monitor the volume (V) of liquid (1) pumped by the pump (20) and to generate volume data; and a controller (30) configured to: receive the power data, the volume data, the discharge pressure data and the level data; process the discharge pressure data to determine a discharge head

Abstract: A system comprising: a reservoir (14) for holding a liquid (1); a pump (20) arranged to pump the liquid (1) out of the reservoir (14) to a system outlet (24) or into the reservoir (14) from a system inlet; a pressure sensor (34) arranged between the reservoir (14) and the system outlet (24) or between the system inlet and the reservoir (14), the pressure sensor (34) configured to measure the discharge pressure (Pd) of the pump (20) and to generate discharge pressure data; a level sensor (26) configured to detect the level (1) of the liquid (1) in the reservoir (14) and to generate level data; a power monitor (28) configured to monitor the power consumed (p) by the pump (20) and to generate power data; a volume monitor configured to monitor the volume (V) of liquid (1) pumped by the pump (20) and to generate volume data; and a controller (30) configured to: receive the power data, the volume data, the discharge pressure data and the level data; process the discharge pressure data to determine a discharge head

Abstract: A system comprising: a reservoir (14) for holding a liquid; a pump (20) arranged to pump the liquid out of the reservoir (14) or into the reservoir (14); a level sensor (26) configured to detect the level of the liquid in the reservoir (14) and to generate level data; a current monitor (28) configured to monitor the current drawn by the pump (20) and to generate current data; and a controller (30) configured to: receive level data and determine the static head from the level data, and generate head data from the static head; receive first current and head data corresponding to the current drawn by the pump (20) as a function of the static head for a first period of operation of the pump (20); receive second current and head data corresponding to the current drawn by the pump (20) as a function of the static head for a second period of operation of the pump (20), wherein the second current and head data is recorded when the liquid in the reservoir (14) is between a first liquid level and a second liquid level,

Abstract: A distance measurement apparatus arranged to measure the distance to an object (106) comprising a first sonic transmitter (100) arranged at a first distance (h1) from that object and a second sonic transmitter (102) arranged at a second distance (h2) from that object (100), wherein the first and second distances are different, the first (100) and second (102) transmitters being controlled by processing circuitry (108) and the first and second transmitters being arranged such that sonic pulses emitted, in use, thereby are incident upon that object (106) and the apparatus further comprising at least one sonic receiver (100) arranged to receive a plurality of reflected sonic pulses and generate an output therefrom and the processing circuitry (108) being arranged to receive the output, determine the times since the first and second pulses were emitted and generate a distance to that object from the determined times.

Abstract: A distance measurement apparatus arranged to measure the distance to an object (106) comprising a first sonic transmitter (100) arranged at a first distance (h1) from that object and a second sonic transmitter (102) arranged at a second distance (h2) from that object (100), wherein the first and second distances are different, the first (100) and second (102) transmitters being controlled by processing circuitry (108) and the first and second transmitters being arranged such that sonic pulses emitted, in use, thereby are incident upon that object (106) and the apparatus further comprising at least one sonic receiver (100) arranged to receive a plurality of reflected sonic pulses and generate an output therefrom and the processing circuitry (108) being arranged to receive the output, determine the times since the first and second pulses were emitted and generate a distance to that object from the determined times.