Test Method for Agricultural pH Control Agents

This test method is intended for products sold as tank mix adjuvants for use with agricultural products.

Part A provides a determination of whether the pH modification characteristics of the adjuvant tested meet the definition of an acidifier, alkalinity agent, or a basic blend in Terminology E 1519. Part B provides a measure of the buffer capacity of the adjuvant. This can be used to estimate the amount of a buffer that will be required to keep a spray solution at the desired pH.

Other pH standards can be used (see Test Method E 70) as long as the pHs measured are not outside the range of the standards used.

If samples of the material to be used in a particular application are available, the first method can be used to determine what adjuvant rate is required to obtain the desired pH. The ability of an adjuvant to adjust the pH of a particular system will depend on the initial pH before addition.

The second method can be used to determine the amount of an adjuvant required to change the pH of a quantity of spray solution to the required value (see Note 1).

Note 1—Many acidifiers and basic blends also are buffers, so the pH change does not provide a useful measure of buffer capacity.