In lighting design, several different variables are measured, such as illuminance. Measuring these values requires different types of measuring instruments, either static measuring instruments or portable measuring instruments. Depending on the make, the same type of measurement can be measured in different ways. A static measuring instrument is usually measured one time at a specific location, while a portable measuring instrument can, for example, measure every minute or every ten minutes for an extended period. With constant research and technological development, the measurement of lighting variables has become more relevant. It is problematic to conduct experiments with a lack of consistent and accurate methods when measuring light. It is important to have the right conditions for a measurement in order for the results to be of good quality. The purpose of this study is to investigate differences between different static and portable measuring instruments used to describe the exposed illuminance and the physical activity. This is done through a pilot study. The pilot study was conducted using an experimental quantitative method with two participants during one day in four different measurement occasions with six different measuring instruments, the measuring instruments being measured in vertical, horizontal and flexible positions. The analysis showed that the results largely depended on whether a static or portable measuring instrument was used. The results also showed that depending on what position the measuring instruments measure from, the results vary. Based on the results, the conclusion is that the closer to eye level one can get, the more relevant the results are. For further research, all the measuring instruments used in the study should be calibrated prior to implementation. For example, it is important to examine the sensitivity of the measuring instruments when measuring indoors and outdoors. More participants, more measurements and more contexts would have been preferable for further research.