Nozzles and the way they are installed and used determine how well the sprayer performs a specific job, paticularly how rapidly the chemical is distributed. Study the catalogs and literature of the nozzle manufacturers, then choose the nozzles that will give you the spray pattern, spray angle, and droplet size you want.
SprayParts contains comprehensive tables showing the rate of discharge in gallons-per-minute of each nozzle at specific pressures. This data is accurate when the nozzles are new, but nozzle output changes as the nozzle orfice wears, so frequent checking of nozzle discharge rate is important to spraying economy. Another reason for checking nozzle output on your own sprayer is to correct for any variance between your pressure gauge and the precision gauges that are used in the nozzle manufacture's test lab. By using the data you determine for your nozzles and your gauge you can be sure of what is happening in your field. Below is a TeeJet Nozzle seclection guide.