Once the heat load of the system has been calculated, the desired change in temperature between the two ceramics of the TEM (ΔT) can be evaluated. If the desired ΔT is greater than a single stage TEM can provide, another stage can be added and a “Multi-stage TEM” is created. The table here describes the typical maximum obtainable ΔT values for both single and multi-stage TEMs. Data is provided for both dry nitrogen and vacuum environments.