pH Test Strips
pH test strips, sometimes called pH indicator strips, are used to measure pH in water, soil, food, and other substances. A sample is applied to the test strip, which then turns color to indicate the sample pH. Test strips come with a color-coded key, to which the test strip is compared to determine the pH level. In addition to using test strips, pH can be measured using a pH meter. Though they are more cost-effective, pH testing strips are considered less accurate than meters, so they are used to obtain approximate measurements only. They are used in a variety of applications, including water testing, healthcare, aquarium maintenance, wine making, and in food and beverage production. Because they are inexpensive, pH test strips are commonly used in science education.
Each test strip has a specific range and increment. Generally speaking, larger range test strips have larger increments, and smaller range test strips have smaller increments. For example, a test strip with a measuring range of 1 to 14 might only show results in full point increments (for example, 5.0 and 6.0). Test strips with a measuring range of 5 to 8, on the other hand, might have an increment of 0.2 (for example, 6.0, 6.2, and 6.4). As a result, when measuring the same substance, the larger range strip might give a reading of 6.0, while the smaller range strip will give a more precise reading of 6.4. Because of this, wide-range pH strips are generally used for testing materials when the approximate pH range is not known. For more precise measurements when the approximate pH is known, consider a pH test strip with a smaller range.
In addition to general-purpose strips, some pH test strips are designed for a specific type of testing, for instance, water, soil, blood, saliva, urine, or fermented beverages. Saliva and urine pH test strips are used by medical professionals to diagnose health issues and by patients who need to regulate urine pH. Features to take into consideration when purchasing pH test strips include the type of substance being tested, the expected pH range, and the increment required.