There wasn't a single hiccough from the machine to kick out an extrapolator's signal to watch for anything unusual.
He wondered if he dared threaten to send an extrapolator out there to check them over.
1874, a back-formation from extrapolation by analogy of interpolate. Said in early references to be an expression of Sir George Airy (1801-1892), English mathematician and astronomer. Related: Extrapolated; extrapolating.