This work presents a technique that can completely and accurately identify measurement bias in cases where it is not possible to use the method of Rollins and Davis (1992, 1993) and where the method of Narasimhan and Mah (1987) fail to perform accurately. This technique makes use of information contained in the relationship between individual measurements and the corresponding nodal imbalance. The performance of this method is demonstrated on a problem from the literature that has been difficult for other methods to handle. In addition, this article discusses how the new technique can be used as a Visual monitoring tool for identifying biased measured variables. (C) 2000 Elsevier Science Ltd. All rights reserved.