A programmable data acquisition system to allow novel use of meteorological radiosondes for atmospheric science measurements is described. In its basic form it supports four analogue inputs at 16 bit resolution, and up to two further inputs at lower resolution, configurable instead for digital instruments. It also provides multiple instrument power supplies (+8 V, +16 V, +5 V, and -8 V) from the 9 V radiosonde battery. During a balloon flight encountering air temperatures from +17 °C to -66 °C, the worst case voltage drift in the 5 V unipolar digitisation circuitry was 20 mV. The system liberates a new range of low cost atmospheric research measurements, by utilising radiosondes routinely launched internationally for weather forecasting purposes. No additional receiving equipment is required. Comparisons between the specially instrumented and standard meteorological radiosondes show negligible effect of the additional instrumentation on the standard meteorological data.