The HI84529-55 is a 230 mL bottle of pump calibration standard solution that is used for both low and high range determination of acidity in dairy products.The amount of pump calibrations performed will vary on the range selected.

The determination of acidity is made according to a neutralization reaction in which the acids found in dairy products are neutralized by a base. In the United States the acidity of dairy products is usually expressed in terms of lactic acid (% l.a.). Other units of measure include degree Soxhlet Henkel (°SH), degree Dornic (°D) and degree Thorner (°Th).

Analysis of titratable acidity in dairy, as performed on the HI84529 mini titrator, utilizes a simple sample preparation, a high quality titrant dosing pump, potentiometric endpoint detector, and automatic computations. As the titrant comes pre-standardized, it is important to determine the amount of titrant delivered by the dosing pump by performing a pump calibration procedure. In this procedure, the analysis of a known volume of a known solution is titrated with to a fixed pH endpoint determined by the FC260B pH electrode and HI5315 reference electrode.

The HI84529-55 pump calibration solution is used for both the low and high ranges, but the volume used will based on the selected range. The Low Range 20  range uses 1 mL while the Low Range 50  uses 2 mL; the High Range 20  range uses 10 mL of the pump calibration solution. The pump calibration procedure should be performed anytime the titrant, syringe, tubing or pH electrode is replaced. It is recommended to do a pump calibration every time a new set of titrations are to be performed.

Replacement reagents required to operate the HI84529 include: