Measuring accurately

Weighing small amounts

• Use a milligram scale on a level, steady surface away from drafts
• Let it warm up, then calibrate it with the included weight
• Tare the container before adding anything
• Close the draft shield before reading the result

Measuring volume

Beakers are for holding and mixing; their markings are rough. For an accurate volume, use a graduated cylinder and read the bottom of the curved liquid surface at eye level. For very small volumes, an adjustable micropipette is more precise.

Strips or a meter for pH?

Test strips are quick, cheap and good for a rough check. A digital meter gives a precise number, but it needs calibrating with buffer solutions, and its probe must be kept moist between uses.

Write it down

Record each measurement as you take it. A number you try to remember later is a number you cannot trust.