pH measurement of paper, leather, and other surfaces are important during manufacturing and final product stages. In the paper industry, a pH measurement indicates the chemical stability and permanence of a paper. It is desirable to manufacture paper that has a neutral or slightly basic pH to aid in the preservation of important documents, publications, and artworks. An acid-free or alkaline paper is able to absorb damaging acid compounds that are naturally formed through aging.

pH of paper and cartons is also important in the food industry. Food packaging often incorporates antimicrobial agents to inhibit microbial activity during distribution and storage conditions. The activity of antimicrobial agents can quickly change with a variation in pH. pH compatibility tests consider food composition, chemistry of the antimicrobial agents used, and packaging material.

In leather making, tanning is one of the most chemically complex steps. Generally, tanning creates a leather product that is more breathable, flexible, and suitable for use in handbags, luggage, garments, and a variety of commercial items. Tanning is performed by a vegetable method or chrome method; chrome-tanned leather requires the addition of chromium salts and a basic component to raise the pH. The pH of the liquors used in the leather making process and the pH of the final leather product directly affect characteristics such as firmness, heat resistance, and durability.

The HI99171 uses the HI14143 amplified pH electrode with glass body. This specialized electrode offers numerous features that improve surface pH testing. An integrated temperature sensor allows for temperature compensated pH measurements without the need for a separate temperature probe. The probe’s flat sensing tip provides optimal surface contact with samples.

An integral part of any pH electrode is the reference junction. The reference junction is a part of the electrode that allows for the flow of ions located in the reference cell into the sample being tested. It is vital that this flow occurs in order to complete an electrical circuit, which ultimately determines the pH value. Poor contact between the junction and sample will prevent completion of the circuit, resulting in readings that are erratic or constantly drifting.

The flat tip of the HI14143 provides optimal surface contact between the sample and the junction. The HI14143 features an open junction design which utilizes a viscolene reference electrolyte that comes into direct contact with the sample, providing accurate, stable readings.