Abstract: A method and system for determining a density of a fluid is provided. The method is carried out using an electrospraying apparatus connected in the system. At a first step fluid is introduced into an emitter of the electrospraying apparatus. A voltage is applied between the emitter and a counter-electrode spaced apart from the emitter for a number of intermittent time periods, wherein the duration of at least some of the time periods during which the voltage is applied progressively decreases. The current between the emitter and the counter-electrode is measured for each time period during which a voltage is applied and the shortest time period for which a current reading is obtained is recorded. The shortest time period is used to calculate the density of the fluid in the emitter.

Abstract: A method and system for determining a density of a fluid is provided. The method is carried out using an electrospraying apparatus connected in the system. At a first step fluid is introduced into an emitter of the electrospraying apparatus. A voltage is applied between the emitter and a counter-electrode spaced apart from the emitter for a number of intermittent time periods, wherein the duration of at least some of the time periods during which the voltage is applied progressively decreases. The current between the emitter and the counter-electrode is measured for each time period during which a voltage is applied and the shortest time period for which a current reading is obtained is recorded. The shortest time period is used to calculate the density of the fluid in the emitter.

Abstract: A method of providing a suitable candidate liquid for an electrospray system is provided. At a first step an aperture radius for an aperture of the electrospray system (10) through which the liquid to be electrosprayed is drawn is obtained. Next, a corona threshold electric field curve as a function of relative permittivities of candidate liquids is calculated to determine the electric field at which undesirable corona discharge will occur. The maximum surface tension that can be electrosprayed by the system is calculated and then a candidate liquid which has a chosen relative permittivity and a surface tension that is equal to or less than the maximum surface tension is provided, to thereby provide a suitable candidate liquid with an appropriate surface tension to result in electrospray that meets the requirements of the electrospray system.

Abstract: A method for measuring a surface tension of a liquid is carried out using an electrospraying apparatus connected in a system. A voltage source applies a voltage between a capillary through which the liquid is drawn and an electrode of the electrospraying apparatus. An ammeter continuously measures current flowing in the system and if no current or a current less than a predetermined threshold current is measured in the system, the strength of the electric field at the capillary is increased. As soon as current is measured in the system, a reading of a parameter of the system is taken, which is used to calculate the surface tension of the liquid.