Apparatus for measuring impurity concentrations in a liquid

An apparatus for measuring nonvolatile residue particles in a liquid, comprising:

• (a) an atomizer for atomizing liquid and producing droplets;
• (b) an evaporator in flow communication with said atomizer for evaporating the droplets into residue particles;
• (c) a condensation nucleus counter in flow communication with said evaporator for counting the residue particles;
• and
• (d) means for controlling the flow rate of the liquid to the atomizer in flow communication with said atomizer, including a first and second orifice in fluid communication with one another, a pressure sensor and a control valve means, a processing means connected to said pressure sensor and said control valve means, said control valve means in fluid communication between said first and second orifices so as to respond to signals generated from said processing means, wherein said sensor is positioned and arranged to measure the liquid pressure between said first orifice and said second orifice and the pressure measurements are provided to said processing means, and wherein variations of the pressure are automatically compensated for by said processing means so as to provide constant liquid delivery to the atomizer, said control valve means in flow communication with a fluid disposal means for disposing fluid, wherein when the pressure is above a predetermined value, said processing means provides a signal to said control valve means which opens allowing more fluid to flow into said fluid disposal means and when the pressure is below a predetermined value, said processing means provides a signal to said control valve means which closes allowing less fluid to flow into said disposal means.

A nonvolatile residue particle analyzer in combination with an atomizer and a liquid supply, said atomizer in flow communication with said liquid supply which is constructed to atomize the liquid in said supply into droplets which are subsequently dried to nonvolatile residue particles in an evaporator which is in flow communication with said atomizer, the residue particles being counted by a counting means connected to said evaporator, said combination further comprising:

• (a) first fluid restrictive means, in fluid communication with the liquid supply, for producing an approximate flow rate;
• (b) second fluid restrictive means, arranged and configured in fluid communication with said first fluid restrictive means, for restricting fluid flow to the atomizer;
• and
• (c) variable fluid restriction control means, located in fluid communication between said first and second fluid restrictive means and responsive to variations in the liquid pressure between said first and second fluid restrictive means, for compensating for changes in the pressure variations, whereby variations of the pressure are automatically compensated for so as to provide constant fluid delivery to the atomizer.

A fluid delivery apparatus in combination with a liquid supply and an atomizer constructed so as to atomize the liquid in the supply into droplets, said combination further comprising:

• (a) first fluid restrictive means, in fluid communication with the liquid supply, for producing an approximate flowrate;
• (b) second fluid restrictive means, arranged and configured in fluid communication with said first fluid restriction means, for restricting fluid flow to the atomizer;
• and
• (c) variable fluid restriction control means in fluid communication between said first and second fluid restrictive means and responsive to fluctuations in fluid pressure between said first fluid restrictive means and said second fluid restrictive means, for automatically compensating for fluctuations in the fluid pressure, wherein variations in the fluid pressure are automatically compensated for so as to provide constant fluid delivery to the atomizer.

An apparatus for measuring the nonvolatile residue concentration of a fluid, comprising:

• (a) an atomizer for mixing the fluid with clean air or nitrogen to produce droplets having a constant size distribution;
• (b) an evaporator connected to said atomizer for evaporating the droplets leaving residue particles;
• (c) first fluid restrictive means for producing an approximate flowrate of the fluid;
• (d) second fluid restrictive means, located in fluid communication downstream from said first fluid restrictive means, for restricting fluid flow to the atomizer;
• (e) variable fluid restriction control means, located in fluid communication between said first and second fluid restrictive means and responsive to pressure between said first fluid restrictive means and said second fluid restrictive means and for compensating for changes in the pressure;
• whereby variations of the pressure are automatically compensated for so as to provide constant fluid delivery to the atomizer;
• and
• (f) measuring means, connected in fluid communication with said evaporator, for measuring the concentration of the detectable nonvolatile residue particles.