摘要 |
<p>A test substrate for determining concentration of an organic corrosion inhibitor in a coolant fluid is provided. The test substrate comprises a porous substrate having at least a surface treated with a sufficient amount of at least a metal salt for reacting with a molar equivalent amount of the organic corrosion inhibitor in a representative sample of the coolant fluid, and at least a color indicator. The color indicator reacts with the metal salt and/or the organic corrosion inhibitor, forming an irreversibly colored complex and causing a color change in the test substrate.</p> |