SEN0554 Turbidity sensor -- distance between probes

The manual states that the probes should be placed 40-50mm apart. I'm wondering if they can be placed closer because my particular application needs to detect turbidity of water that's flowing through a 25mm tube. Is there an equation that would allow me to convert the readings from the sensor (which was perhaps calibrated for 40-50mm separation) so that they are “normalized” to 25mm separation?