English to Russian Tech/Engineering Mechanics / Mech Engineering Air heaters

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To properly assess air heater performance, the temperatures in and out of both sides of the air heater need to be known, as well as the oxygen concentrations before and after the gas side of the air heater. Velocity heads need to be measured, as feasible, to determine if there are any significant flow stratifications in the ducts. If so, the temperature and oxygen should be normalized *on a flow-weighted basis*. Furthermore, to perform a proper thermal heat balance, the air and gas flows before and after the air heater also need to be measured.