Disposable sampling device for particle counting apparatus

A method for diluting and detecting particles in a sample liquid contained in a disposable sampling device comprising the steps of:

• moving a piston in a first direction from a first position to a second position to displace a defined volume of a diluting liquid contained in a cylinder through a metering means into a diluting chamber, said defined volume of said diluting liquid also delivering a defined volume of a sample contained in said metering means to said diluting chamber;
• moving said piston in a second direction from said second position to said first position to withdraw a combined volume of said defined volume of sample diluted by said defined volume of diluting liquid from said diluting chamber to said cylinder;
• further moving said piston in said second direction past said first position towards a third position, thereby opening a measuring conduit and causing air to be let into said cylinder therethrough;
• and
• moving said piston in said first direction from said third position to said first position, thereby expelling at least a portion of said combined volume through said measuring conduit past a particle detecting means.

A disposable sampling device for collecting a sample fluid containing particles to be counted comprising:

• a housing having an outer wall with a sample inlet therein for applying a sample of fluid to the device;
• said housing having therein
• a metering means for collecting a defined volume of sample from the inlet;
• a valve body for connecting said metering means to a cylinder;
• a piston for dosing a defined volume of diluting liquid held within the cylinder into the metering means thereby forcing the defined volume of sample in the metering means to a dilution chamber for diluting the sample with the defined volume of diluting liquid;
• and
• a measuring conduit means connectable by said valve body to the cylinder upon the cylinder receiving a mixed volume of sample and diluting liquid from the dilution chamber.