Patent ID: 8899450

Claim:
A method of dispensing a specified volume (V tot ) of liquid using a pump comprising the steps of: (i) defining a total charge amount (Q tot ) corresponding to the specified volume of liquid; (ii) providing a pulse from a portable voltage source to an electromagnet, wherein the pulse energizes the electromagnet to displace a magnetisable pumping member of the pump; (iii) measuring at least one current value (I m,n ) of the pulse; (iv) estimating a supplied charge amount (Q m ) supplied to the electromagnet by the pulse, based on the at least one current value; (v) determining an accumulated charge amount (Q), based on the supplied charge amount (Q m ); and (vi) repeating steps (ii), (iii), (iv), and (v) until the accumulated charge amount (Q m ) is greater than or equal to the total charge amount (Q tot ).