Assessing the quality and behavior of the water jet produced by the nozzle can provide indirectly information about the quality and condition of the nozzle. There are many different ways of selecting the best nozzle for a given application or comparing the performance of several nozzles. A special method for measuring the impact pressure of a high velocity water jet was developed at the Institute of Geonics of the Czech Academy of Sciences. The impact pressure of the jet generated by the nozzle is measured using a specially designed sensor. The paper presents results of measurements of impact pressure of the jet generated by two types of nozzles - a cylindrical nozzle and a flat jet nozzle – using two modes of measurement: in lines and point-by-point. The performed experiments and results showed that both methods are fully consistent and suitable for assessing the quality and condition of a given nozzle. The in-line measurement method is preferable for routine nozzle quality determination. It is less time-consuming and provides more detailed information on the distribution of the impact pressure across the jet. The point-by-point method allows a more accurate analysis of the dynamic behavior of the jet at individual points in the cross-section of the jet.