We present a novel and generalised notion of doping cleanness for
cyber-physical systems that allows for perturbing the inputs and observing the
perturbed outputs both in the time- and value-domains. We instantiate our
definition using existing notions of conformance for cyber-physical systems. As
a formal basis for monitoring conformance-based cleanness, we develop the
temporal logic HyperSTL*, an extension of Signal Temporal Logics with trace
quantifiers and a freeze operator. We show that our generalised definitions are
essential in a data-driven method for doping detection and apply our
definitions to a case study concerning diesel emission tests.