Model 694 Hellige-Truog soil ph testing kit is the most accurate inexpensive outfit for testing ph of any sample of soil, sand, clay or peat. It does 200 tests. The triplex indicator solution produces distinct shades of color over all ranges of the scale. It eliminates errors by use of an inert white powder to draw the reagent from soil to its surface for comparison. You get an accurate color comparison with the laminated color chart supplied. When low cost water tests are most important, the compact & inexpensive Simplex kits permit anyone to do accurate on-site chlorine and ph testing easily and quickly.