A: Hello Jaunts , Unsure what pH chemistry indicator is used, but a clay soil vs loam soil, i'd think only difference is on how finely the dirt is crushed,and then how well the soil is wetted (you shaking the water mix) to totally make the soil available to the water soluble reagents (the water is colored with soluble pH die/reagent, and not that you are dissolving the dirt to make the color).so in my opinion , settling of the non-water solubles (very fine decayed twigs ,leaves , or clay(fine inorganic particles) , will effect the resulting color you see. Let it settle till near clear water (very little particles noticed when shining a light through the cell) .
A: Yes, the tester will work on clay soil .
A: While holding the capsule above the sample tube, squeeze or roll the thinner half gently to break the "seal" or friction bond holding the two halves together. Then start twisting the two halves in different directions while gently pulling them apart.
A: Not spilling powder is tough. i made a small paper funnel to catch most into the small cell throat. maybe taping each side with large bit of packing tape, and pulling on the tape to have a better handle on each side would allow better handling ??
A: Hold capsule and slowly rotate one end back and forth very gingerly while pulling up at the same time until you have separation of the two halves of the capsule.