The Tritium module is a trigger generator based on the Poisson process model which is similar to Radioactive decay.
The top knob controls the rate of decay, measured in Becquerels (decays per second)
The bottom knob controls the stability of the module. Fully to the left it will be completely random intervals. Fully to the right it will be completely stable intervals. In this case the module will act as a clock with the decay rate measuring the frequency.