As you can tell from the title of this section, you will first describe the apparatus and then the ways in which you used it. Include diagrams of equipment and describe the steps you took to operate the equipment.

When describing the apparatus, use present tense verbs; when stating your procedure, use past tense verbs. When discussing the methods used, avoid the mere listing of exact steps. Try for more descriptive, less prescriptive language, as in the example below:

All measurements were carried out with concurrent upflow of both phases. The gas phase, air, was introduced at the bottom of the column through a perforated distributor plate after being metered with rotameters. A wire-mesh packing was provided below the distributor plate to avoid any possible maldistribution of gas at its entry point. The superficial gas velocity ranged from 0.01 to 0.16 m/s. The pressure in the gas inlet line was measured using pressure gauges. The liquid phase, tap water, was pumped from a storage vessel through the column and then recycled. The liquid flow rate was measured using a liquid flow rate indicator. The superficial liquid velocity varied from 0.005 to 0.03 m/s. Both columns were equipped with eight equally spaced connections for pressure transducers, each placed at a regular interval of 0.3 m along the column length.3