Steady-state and adiabatic calorimeters were used successfully to measure radiation heating rates in lead and polyethylene samples in various facilities at the Livermore Pool-Type Reactor, With the steady-state calorimeter, rates were determined by the temperature difference across a known thermal resistance connecting the samples to a heat sink. The adiabatic calorimeter was used to determine heating rates by the rate of change of temperature in the sample at the time the sample and heat sink temperature were the same. The adiabatic calorimeters were easier to construct, but required more time for measurement.