A small oscilloscope necessary to balance the bridge is NOT included in the supply. The filament heating circuit voltage does not exceed 12V and the system has an isolated mains transformer. It is self contained and built into a high quality instrument case designed for bench mounting with the experiment easily visible. A second vessel with cooling system accommodates the second arm of the bridge, a variable voltage supply for filament heating, the AC bridge circuit, a panel mounted ammeter and voltmeter, switch gear, electrical stirring system and a 0-105ºC thermometer. It consists of the heat proof glass observation vessel containing the liquid and housing the nickel filament whose length and diameter can be measured, together with an additional low voltage heating element for rapid warm up.
....
A Cooling fan is supplied with a speed controller to control the airflow over the heat exchanger. Water temperature is also measured via the inbuilt thermocouples of the base unit. Thermocouples are placed before and after the fan to measure air temperature.
....
The unit includes instrumentation that is common to all modules, this being a 12 point digital tempe. A fully instrumented bench top Heat Transfer Service Unit providing regulated and adjustable AC power for all of the optional modules plus a number of auxiliary power outlets.
....
A small-scale accessory that allows experimental investigation of linear heat conduction and the measurement of the thermal conductivity of various solid conductors and insulators.
The hot end uses a nominal 65W heater (operating at 240v maximum), which is fitted with a high temperature limit switch. The power supplied to the heater is controlled and measured by the Heat Transfer Service Unit .
The cold section is of identical dimensions to the hot end and is water-cooled. Both the heated and cooled ends are each fitted with three thermo couples at 15mm intervals to measure the temperature gradients along the bars.
An insulated, 25mm diameter brass heated section and cooling section that may be either clamped together, or assembled with one of four insulated intermediate sections or test specimens between the interfaces.
A bench top service unit makes it possible to supply the electrical feedings and measurement facilities. The Heat Transfer Study Units has been designed to carry out experiments concerning the basic modes of heat transfer. Thus the student can investigate conduction, convection, radiation and their combined effects, non-steady state and measurement errors.
....
Intended use:
To transfer liquids in general clinical laboratory applications.
The unit is supplied with manuals which describe all parts of the unit, the installation and utilization procedures, as well as many exercises with experimental results. The Computerized Air Water Heat Transfer Apparatus allows to perform several experiments relevant to the thermal exchange phenomena connected to convection and conduction and some interesting experiments on fluid dynamics. Moreover, the transducers and the dedicated software allows the data acquisition of the main thermodynamics quantities and to obtain or as a table or as a graph, the acquired values and the thermodynamic calculated quantities. In particular, it is possible to study the thermal exchange between a gas (air) and a liquid (water) and the thermal exchange between an air flow rate in a forced motion and a wall at different temperature.
....
The unit is supplied with manuals which describe all parts of the unit, the installation and utilization procedures, as well as many exercises with experimental results. The Air water Heat Transfer Apparatus allows to perform several experiments relevant to the thermal exchange phenomena connected to convection and conduction and some interesting experiments on fluid dynamics. In particular, it is possible to study the thermal exchange between a gas (air) and a liquid (water) and the thermal exchange between an air flow rate in a forced motion and a wall at different temperature.
....
The apparatus consists of a small test cylinder. The temperature of cylinder is measured with the help of temperature sensor inserted in the center. The hot water bath is provided with a heater and is controlled by digital temperature controller. The cylinder is heated by a constant temperature water bath, till steady state is reached. During heating, temperature of the cylinder is function of time and hence, heating of cylinder is under unsteady state heat transfer. An agitator is also provided to maintain the constant bath temperature.
Experimentation:
To calculate the heat transfer coefficient.
To calculate the Biot number, Fourier number.
The heat and light sources, instruments, filters and plates are mounted on an aluminium track with graduated scale, which is designed to stand on the benchtop and connect to the Heat Transfer Service Unit without the need for tools.
A heat source with radiometer and a light source with light meter are used where appropriate to demonstrate the principles.
A small-scale accessory designed to introduce students to the basic laws of radiant heat transfer and radiant heat exchange.
The light source consists of a 40 Watt light bulb (operating at 24V DC maximum) mounted inside a housing with a glass diffuser.
The heat source consists of a flat circular plate 100mm in diameter which incorporates a 216 Watt electric heating element (operating at at 24V DC maximum).
A comprehensive instruction manual is supplied.
Examination of heat conduction in solids
Radial heat conduction: brass disc with heating and cooling element, 6 temperature measuring points
Linear heat conduction: 3 measuring objects, heating and cooling element, 9 temperature measuring points
Experimental setup consisting of experimental unit and display and control unit
Electric heating element
Cooling with mains water.
Intended use:
To transfer liquids in clinical laboratory settings applicable for molecular/PCR & sterile microbiological works.
A bench top service unit designed to interface to a range of heat transfer accessories.
Provides a drive signal for a proportioning solenoid valve used for flow control.
Provides a control signal to a variable speed blower used for generating airflow.
Provides a variable, stabilised 0-24V DC supply to the heater of the heat transfer accessory, with a current capability of 9A.
10 temperature inputs and conditioning circuits for K-type thermocouples:
9 off, 0-133°C, resolution <0.1°C
1 off, 0-500°C, resolution <0.15°C
A comprehensive instruction manual describing how to carry out the laboratory teaching exercises in non-steady state heat transfer and their analysis as well as assembly, installation and commissioning is included.
Outputs can be controlled manually from the front panel, or controlled by the software from a user supplied PC.
Instrumentation inputs for heater voltage, heater current, air flow, water flow, radiation and light meter.
Integral USB interface, and educational software for all accessories.
Experimentation:
To determine the effective thermal conductivity of the composite cylinder.
To compare the theoretical temperature profile within the composite cylinders, with that of observed profile.
To estimate the actual rate of heat transfer through the composite cylinders from the measured interface temperature of the two insulating materials with known thermal conductivities.
To transfer liquids in clinical laboratory settings applicable for molecular/PCR & sterile microbiological works.
....
The computerized version unit allows, thanks to the electronic transducers and suitable software, to display on personal computer and/or print the tables of results and diagrams of the various experiments. The Computerized Boiling Heat Transfer Apparatus has been designed to perform experiments concerning heat transfer due to convection in a boiling liquid (water). The second leg of the bridge is used to balance the nickel wire and is immersed in a cooling vessel filled with water. The unit is supplied with manuals that describe each component of the system, installation and utilization procedures, and gives many exercises. The unit consists of a vessel containing a quantity of water continuously stirred and heated by a nickel filament. Since this wire is a leg of an alternate current bridge, the temperature can be measured very accurately.
....
A bench top service unit makes it possible to supply the electrical feedings and measurement facilities. The Computerized Heat Transfer Study Units has been designed to carry out experiments concerning the basic modes of heat transfer. Thus the student can investigate conduction, convection, radiation and their combined effects, no steady state and measurement errors.
....
It allows analyzing the behaviour of an element with proportional transfer function able to oscillate, with a delay of the second order, both in the time domain and in the frequency domain.
....
Sensors measure temperatures (upstream and downstream of the heating element and inside the Heating element), flow velocity of the air and heating power
Heat transfer in the air duct by free and forced convection
3 heating elements with different surfaces: flat plate, tube bundle or fins
Air duct with axial fan.
Display and control unit indicates air temperature, heater temperature and heating power
2 heaters can be inserted in a bundle or alone
Air flow rate adjustable
Convective heat transfer
Exchangeable pipe bundle as heat exchanger
Pitot tube and pressure measurement station to determine air velocity.
