The Hydrion Mechanical pH Pencil measures the pH of any surface to the nearest full pH value
The Hydrion pH pencil can be used to test irregular or uneven surfaces
Is also effective on porous material and impervious solids
The pH Pencil is used to detect acid or alkali residues
It offers clear bright single color matches at every 1.0 interval from pH 0.0-13.0. 3 Pencils and 3 Color Charts included.