The Ionograph is Closed Loop Ionic test system that uses a 75/25% (Isopropyl / DeIonized Water) Ion Extract Test Media. The test media is pumped from the Test Cell to the Probe. The Probe measures the Conductivity / Resistivity & Temperature of the solution. The solution is then pumped through the Mixed Bed (Anion & Cation) DeIonization Column(s) and then back into the Test Cell. The Conductivity of the Solution Decreases as it is DeIonized

The pump runs continuously, therefore the test media is deionized to reach a point of equilibrium with the Airborne contamination being absorbed into it. Airborne contamination is mostly CO2 (Carbon Dioxide) of the air. It is at this point the instrument is ready for testing. The test is started and a Baseline Conductivity of the solution is measured. The sample to be tested is thenplace into Test Cell containing the Test Media. Contamination from the test sample is ionized into the Test Media. The Ionization of the contamination causes an Increase in conductivity of the Solution. The Test Media is being DeIonized by the DeIonization Column(s) at the same time the contamination from the Test Sample is Ionizing it. When all of the contamination has been removed from the Test Sample the Test Media will  be DeIonized back to its’ Starting Baseline Conductivity and the test is then Terminated.

As the Test Media is pumped through the probe, the Conductivity of it is measured approxamently every 2 seconds. The change in conductivity from its’ starting baseline conductivity is calculated. This change in conductivity is compared to the amount of NaCl(Sodium Chloride) it would take to cause the same amount of change in conductivity. This amount of NaCl is added to the amount measured from each previous sample. When the measured conductivity equals the Baseline Starting Conductivity the Test is terminated.

The Ionograph measures changes in Conductivity of the Test Media and relates that change to the Standard which is an Equivalent Amount of NaCl. All ionic contamination causes a change in Conductivity, therefore the Ionograph is not able to distinguish between different types or quantities of contamination, but as a lump sum quantity.