  The advent of silicon photomultipliers has enabled big advances in high
energy physics instrumentation, for example by allowing the construction of
extremely granular hadronic calorimeters with photon sensors integrated into
small scintillator tiles. Direct coupling of the SiPM to the plastic
scintillator, without use of wavelength shifting fibers, provides a fast
detector response, making such devices well suited for precise timing
measurements. We have constructed a setup consisting of 15 such scintillator
tiles read out with fast digitizers with deep buffers to measure the time
structure of signals in hadronic calorimeters. Specialized data reconstruction
algorithms that allow the determination of the arrival time of individual
photons by a detailed analysis of the recorded waveforms and that provide
automatic calibration of the gain of the photon sensor, have been developed. We
will discuss the experimental apparatus and the data analysis. In addition, we
will report on first results obtained in a hadronic calorimeter with tungsten
absorbers, providing important constraints on the time development of hadronic
showers for the development of simulation models.
