LAUSR

Magnetic flux measurements of toners can aid in the rapid differentiation of toner‐printed specimens in the context of investigations of forgeries or alterations of printed documents. However, some variables that may impact magnetic flux measurements, including hysteresis effects, are not currently well understood. This study assessed the impact of hysteresis and other induction spatial effects on magnetic flux measurements of toners analyzing five toner‐printed samples produced from different devices. The samples were printed with controlled grids of square, rectangular, and elongated rectangular blocks with the same area. Thirty measurements were conducted on each sample, on each grid type. The measurements were repeated in planes of rotation 90°, 180°, and 270° counter to this original position. The values obtained for the square grids were evaluated using one‐way ANOVA to assess the presence and impact of hysteresis effects. The values obtained for the rectangular grids were compared with those obtained for the square grids using a two‐way ANOVA to determine potential induction current orientation effects. The results of both one‐way and two‐way ANOVA were significant with p < 0.05, indicating that both hysteresis effects and induction current spatial effects contribute significantly to variations in magnetic flux measurements. Results confirmed that sensor orientation is an important factor that must be accounted for in method protocols for the measurement of magnetic flux of toners. Controlling these variables is a step forward toward the development of a reliable screening method to be deployed in the context of investigations of document forgeries or alterations.