HT15 – Extended Surface Heat Exchanger
A long horizontal rod, which is heated at one end, provides an extended surface (pin) for heat transfer measurements.
Thermocouples at regular intervals along the rod allow the surface temperature profile to be measured.
Description
A long horizontal rod, which is heated at one end, provides an extended surface (pin) for heat transfer measurements.
Thermocouples at regular intervals along the rod allow the surface temperature profile to be measured.
Hardware Description
The rod is manufactured from brass and mounted horizontally with support at both ends positioned to avoid the influence of adjacent surfaces. The rod is coated with a heat-resistant matte black paint, which provides a consistent emissivity close to unity.
It is heated by an electric heating element, which operates at low voltage for increased operator safety and is protected by a thermostat to prevent damage from overheating.
Eight thermocouples are attached to the surface of the rod at equal intervals of 50mm, giving an overall instrumented length of 350mm. Another thermocouple is mounted adjacent to the heated rod to measure the ambient air temperature.
The heated end of the rod is mounted coaxially inside a plastic housing, which provides an air gap and insulates the area occupied by the heater, in order to minimise heat loss and prevent burns to the operator.
The measurements obtained can be compared with a theoretical analysis of thermal conduction along the bar combined with heat loss (heat transferred) to the surroundings by the modes of free convection and radiation simultaneously.
Technical Specifications
Features & Benefits
- Determining the combined heat transfer (Q radiation + Q convection ) from a horizontal cylinder in natural convection over a wide range of power inputs and corresponding surface temperatures
- Measuring the domination of the convective heat transfer coefficient Hc at low surface temperatures and the domination of the radiation heat transfer coefficient Hr at high surface temperatures
- Determining the effect of forced convection on the heat transfer from the cylinder at varying air velocities

- A small-scale accessory designed to demonstrate the temperature profiles and heat transfer characteristics for an extended surface when heat flows along the rod by conduction and heat is lost along the rod by combined convection and radiation to the surroundings
- The extended surface comprises a 10mm-diameter long solid brass rod mounted horizontally and heated at one end with a 20W, 24V DC heater
- Eight thermocouples mounted at 50mm intervals along the rod provide the temperature distribution
- The temperature of the ambient air is measured by an independent thermocouple
- The accessory is mounted on a PVC baseplate, which is designed to stand on the benchtop and connect to the Heat Transfer Service Unit without the need for tools
- A comprehensive instruction manual is included
All electrical requirements are obtained from the service unit – HT10XC
PACKED AND CRATED SHIPPING SPECIFICATIONS
Volume: 0.01m³
Gross Weight: 5Kg
Length: 0.50m
Width: 0.15m
Height: 0.15m
HT15