close up bottles and blue cap with green, red and clear solution buffer ph 4, 7 and 10 for analysis and calibrate the ph meter.

analysis background batch bench blue blur bottle bottles buffer calibrate can cap chemical chemistry clear close concentration container determination environmental equipment experiment glassware green has health indicator industry lab laboratory lines liquid measurement medical medicine meter pharmaceutical process production reaction reagent red result sample science set silicate size solution solvent space standard technology test testing use vehicle vial volume