Integrators measure the UV energy received and output the measurement in an arbitrary manner. In other words, the numbers cannot be translated to even another NuArc integrator unit; they're sensor / integrator specific. Nevertheless, it's possible to calibrate the integrators to make their measurements match (where, additionally / optionally, 1 unit = 1 sec.), but that would be an exercise in futility because a.) Bulbs change output with age and voltage (each bulb at its own pace, depending on usage etc. ...) therefore you would need to calibrate often and b.) you actually don't need to know the absolute UV energy at all, why would you?