This paper addresses continuous wave (CW) electromagnetic induction (EMI) measurements of wire loops (q-coils) and low metallic (LM) content landmines. Most importantly, measurement errors are addressed. A method based on the measurement of a q-coil with an analytically calculable response is used to produce an error correction function. When this function is used to correct EMI CW measurements of other objects cross over frequency errors are reduced relative to the uncorrected case on average by a factor of 2. Insights into the sources of systematic errors are provided through the analysis of a simple equivalent circuit model of the EMI measurement system.