Fiber length is a crucial property throughout many textile processing steps. The high volume instrument (HVI) is the most commonly used tool to assess the properties of cotton fibers. The HVI currently reports two length parameters, the upper-half mean length (UHML) and uniformity index (UI). The UI is the ratio of mean length (ML) to the UHML expressed as a percentage. UHML and ML are extracted from the fibrogram. These parameters are used in the current U.S. cotton classification and global cotton marketing systems. The two values are highly correlated and characterize only the longer fibers in a sample. The fibrogram holds more descriptive information than the two measurements provided by the HVI. However, limited information is available about the stability and repeatability of the fibrogram measurement. This study aims to investigate the stability of the fibrogram, assess the reproducibility across multiple instruments, and determine if corrective actions are required. Three different raw cotton sample sets were tested for this three-stage experiment. The obtained results demonstrate that for a given HVI, the entire fibrogram is stable over both the short term and long term; however, differences among HVIs were observed. The proposed correction procedure effectively reduces the differences among the four HVI lines.