Acid field test kit for refrigeration oils containing a leak detector
AssigneeVirginia Chemicals Inc.
InventorLeonard C. Ellis
Life of this patent
Estimating the term…
Abstract
A field test kit which uses a single vial is useful in testing acidity in refrigeration oils contaminated with a colored leak detector. This vial contains a pre-measured indicator solution and has sufficient additional volume that the test oil can be added directly to the indicator solution and accurately measured within the vial. After shaking, the mixture quickly separates into two phases. The color of the bottom phase indicates whether or not the acidity of the refrigeration oil exceeds 0.05 acid number.
Claims29
An acid field test kit for determining the acidity of oil samples, said test kit being of the two-phase type and operable within a single vial which has a selected internal volume, and said test kit being used:
- for measuring a sample of a refrigeration oil containing a highly colored leak detector;
- for carrying out a test procedure on said sample by fast phase separation into a solvent top layer and a highly ionic aqueous bottom layer;
- and for obtaining reliable test results as to acidity of said oil;
- and said test kit comprising:
- A. at least one said vial having a means for indicating said selected internal volume;
- B. a water-immiscible solvent, which is disposed within said vial;
- and
- C. an indicator stock solution which is disposed within said vial, comprising:
- (1) 20-28% by weight of a lower alcohol,
- (2) 56-79% by weight of water,
- (3) 6-12% by weight of a water-soluble inorganic salt,
- (4) 0.2-0.3% by weight of a concentrated aqueous solution of a selected indicator having an unmistakable first color at a selected baseline pH which is at about the alkaline limit of the pH range for said indicator,
- (5) sufficient alkaline hydroxide solution to create said baseline pH, and
- (6) an amount of alkaline hydroxide solution which permits an unmistakable selected second color to appear within said aqueous bottom layer only when the acid number of said oil sample exceeds about 0.05 by limiting the change in pH from said baseline pH to a selected acidic pH at about the acid limit of said pH range after said oil sample has been mixed within said vial with said water-immiscible solvent and said indicator stock solution.
The process of assembling an acid field test kit for determining acidity of refrigeration oil samples, comprising:
- A. dissolving a pH indicator, having a pH range of about 8-10, in distilled water to form a concentrated aqueous indicator solution;
- B. preparing an indicator stock solution under an inert gas atmosphere by the following steps:
- (1) preparing an indicator mixture by mixing 20-28% by weight of a lower alcohol, 56-79% by weight of distilled water, 6-12% by weight of a water-soluble inorganic salt, and 0.2-0.3% by weight of said concentrated aqueous indicator solution;
- (2) using a pH meter, adjusting the pH of said indicator mixture to 9.5 by adding 1.0 N alkaline hydroxide solution to said indicator mixture to form an adjusted mixture;
- (3) adding to said adjusted mixture, to form said indicator stock solution, exactly the amount of additional alkaline hydroxide solution that the weight ratio of oil to be tested to one milliequivalent of said additional alkaline hydroxide is 1122;
- and
- C. preparing a plurality of test kit vials, each vial having a mark thereon to indicate a selected internal volume, by the following steps while protecting the contents thereof with an inert gas:
- (1) adding to said each vial a quantity of a water-immiscible solvent equalling 22.7 percent of said selected internal volume, and
- (2) adding to said each vial a quantity of said indicator stock solution equalling 51.4 percent of said selected internal volume, said oil to be tested in each said test kit vial being obtained from said refrigeration oil samples and being added within said selected internal volume up to said mark.
Dependencies are inferred from the claim text.