The standard should read 130uS electrical conductivity on the probe. If this reading is not achieved the probe is adjusted to match the standard reading. Dr. Allard explains the significance of pH within aquatic and terrestrial habitats. Paul Ayers captures digital images with a Casio camera to add to his daily journal. The pH is then read by looking at the standard colors.
Free oxygen is a critical factor in determining what organisms live in certain aquatic habitats.
The chemical reaction that occurs causes a color change that is followed by the addition of another reagent using a precisely calibrated glass syringe which allows the user to read the amount of reagent added. Precision is very important. Sharon Butler has almost reached endpoint of her titration sample.