An experimental facility was designed and built to study the loading on steam generator tubes during a blowdown. The facility used refrigerant R-134a and measurements were taken for static and dynamic pressures as well as tube loading and temperatures. Commissioning experiments indicated that the off-the-shelf dynamic pressure transducers and load cells could not take the mechanical and thermal shock loading caused by the blowdown and produced spurious results of no value. This paper presents the instrumentation problems found, explains why they occurred, describes the remedial procedures employed, and outlines the instrumentation validation methodologies developed. The success of the instrumentation development is demonstrated in a series of experiments designed to assess the rapid transient measurement system.