Precision Laboratories’ test strips are manufactured under strict quality assurance procedures to ensure our customers receive the best possible product. Since we have already shared the quality assurance procedures for our dipslides, we thought we would also share the procedures for our test strips, as these are our primary products.

Raw Materials

quality assurance procedures, raw materialsLet’s start with the sourcing of raw materials. We have an approved list of vendors, and we purchase exclusively from those vendors. However, even when raw materials arrive, we are still always checking their quality.

Many of our chemical sources are from well-known companies, such as Sigma-Aldrich or Archer Daniel’s Midland (ADM). Our paper is also supplied from well-known sources, such as Whatman or Ahlstrom. Our primary raw materials are always purchased from reliable sources.

While these sources are reliable, there are still always variations from batch to batch, particularly with chemicals and paper. This can always cause slight changes to test strip results, but we test every batch to determine whether these changes are large enough to require a hold, or if they’re so slight, it won’t be noticeable to most users. The latter is most often the case.

Production

Our production occurs in three general phases: chemically treating & drying the paper, cutting and/or slitting the strips, and packaging. After the first phase, when the paper has been treated and dried, it is tested in the lab to ensure it is performing as it should. The papers are checked against standards, usually on both ends of the color chart spectrum, and one or two places in the middle.

sensitivity ammonia leak detection cloth, ammonia leak detection cloth, leak detection, quality assurance proceduresAs long as the strip matches the color chart within ± ½ color unit, the strip and color chart are considered acceptable. It’s important to note that some color charts and strips are more accurate than others. For example, our chlorine test papers are a quick, qualitative test method to check for bleach in a solution. The purple colors on the chart are not as easy to distinguish, as say the colors on the Mid-Level Chlorine test strip, which is a more accurate test.

Once tested, the papers are cut using our industrial cutter with a pre-set computer program to cut the strips to the same size every time. Any papers that are applied to plastic are applied using double-sided adhesive, which has also been tested and approved not to interfere with the paper. The plastic strips are often tested again to verify that the adhesive has not interfered with the test. This is particularly true for newly developed test strips.

During the last phase of production, vials, boxes, bags, labels and other packaging supplies are inspected to eliminate any faulty or imperfect items. Products are tightly sealed to ensure proper storage. The packaging process may result in gained or lost strips, but this is within ± 5%.

Guarantee

If we receive complaints of faulty products, we always follow-up. More often than not, it’s a case of incorrect use of the product, and we always walk our customers through the logic and reasoning. Many of our blog articles explore the correct use of various test strips, as well as some ways they cannot and should not be used. However, if we find there is an issue with the strips, we investigate, correct the problem, and send replacements as quickly as possible. Customer satisfaction is very important to us, and we strive to continuously improve.