If operating using the console:1. Switch on the front mains switch. (If the panel meters do not illuminate check theRCD and any circuit breakers at the rear of the service

unit; all switches at therear should be up.)2. Set the selector switch to MANUAL.3. Set the upper selector switch on the HT10X to position Ua to indicate the airvelocity in the duct.4. Start the centrifugal fan by pressing the switch on the connection box.5. Open the throttle plate on the front of the fan by rotating the knob at the center togive a reading of 0.5 m/s on the upper panel meter.6. Set the heater voltage to 20 volts by adjusting the voltage control potentiometerto give a reading of 20 volts on the top panel meter with the selector switch set toposition V.7. Allow the HT14 to stabilize. The HT14 will be stable once the temperaturereading remains constant for at least 90 seconds. Monitor the differenttemperatures using the lower selector switch/meter. NomenclatureNameVoltage to heated cyinderCurrent to heated cylinderPower supplied to heatedcylinderDiameter of heated cylinderHeated length of cylinderHeat transfer areaAir velocity in dụct (freesteam velocity)Corrected air yelocity (due toblockage)Heat loss due to naturalconvectionHeat loss due to forcedconvectionHeat loss due to radiationTotal heat loss from cylinderHeat transfer coefficient fornatural convectionHeat transfer coefficient forforced convectionHeat transfer coefficient forradiationStefan Boltzmann constantEmissivity of cylinderArea factor (geometric factor)Dynamic viscosity of airThermal conductivity of airReynold number (local)Nusselt number (local)Prandtl numberAngular position ofthermocouple (measured fromstagnation point)Surface temperature of heatedcylinder in °CSurface temperature of heatcylinder in KTemperature of ambientair/śurroundings in °CTemperature of ambientair/surroundings in KFilm temperature of airSymbolSI unitQinWmmAsm²Uams1Úcms!QcWQfQrQtotWWWHcWm?K'HfHrWm²K6(= 56.7 x 10")Wm²KDimensionlessDimensionlessReNuPrm'sTWm²K™DimensionlessDimensionlessDimensionlessDegreesT10°CTsKT9°CTaKTilmSubscripts:d= diameterm= mean (average)