Early testers used simple plug-and-play method for simple tubes. Service testers developed for electronics industries in 1950s-1960s. Testers were designed for professional technicians and engineers
KOH test diagnoses fungal infections by examining skin cells under microscope. Test collects cells from affected area and places them on potassium hydroxide slide. Procedure takes few minutes and is usually painless
Biuret test detects peptide bonds and protein content in substances. Test uses 1% Copper II sulphate solution (CuSO₄). Developed by Gustaw Piotrowski in 1857
Practice covers salt spray testing apparatus and conditions for metal corrosion evaluation. Provides controlled environment for relative corrosion resistance testing. Results rarely correlate well with natural environment performance
Soil compaction densifies soil through mechanical stress application. Compaction increases soil strength and decreases compressibility. Maximum dry unit weight occurs at optimum water content level. Water acts as lubricant at dry of optimum, pushing particles apart at wet
H. pylori is a protein found in human stool. Bacteria enters body through oral-to-oral or fecal-to-oral transmission. Most bacteria invade gastric mucous layer, 20% attach to epithelium. Bacteria uses flagella, urease, and coccoid form for survival