Composite Walls Apparatus
Product Code : EL-HTL-11078
Quick answer: The composite walls apparatus is used to find the overall thermal conductivity and thermal resistance of a wall made of layers in series. A 250 mm mica heater sits between mild steel, bakelite and brass or aluminium plates, with thermocouples between the layers, a digital indicator, voltmeter and ammeter. Lab Exports manufactures it in Delhi for engineering colleges, polytechnics and TVET institutes.
Specifications
| Component | Specification |
|---|---|
| Heater | Mica, 250 mm dia. |
| M.S. plates | 2 nos., 250 mm dia., 25 mm thick |
| Bakelite plates | 2 nos., 250 mm dia., 10 mm thick |
| Brass / aluminium plates | 2 nos., 250 mm dia., 15 mm thick |
| Heater control | Dimmerstat, 2 A |
| Power measurement | Voltmeter and ammeter |
| Temperature measurement | Thermocouples with multichannel digital temperature indicator |
| Assembly | Clamped in a frame, viewed through a Perspex sheet |
| Services | 230 V AC stabilised supply with earthing; bench area 1 x 1 x 0.5 m (H) |
How the composite wall experiment is done
When heat flows steadily through layers in series, the same heat rate Q passes through each one, and the temperature drop across each layer is proportional to its thermal resistance, R = L / (k A). The total resistance is the sum, R = L1/(k1 A) + L2/(k2 A) + L3/(k3 A), so Q = (T_hot - T_cold) / R. The apparatus stacks mild steel, bakelite and brass or aluminium plates on each side of the heater, making the idea measurable.
Because the heater is in the middle, half of the electrical input V x I flows through each stack. From the thermocouple readings students calculate the resistance of each layer and the overall conductivity of the composite, and see at once that the bakelite layer, with its low k, carries most of the temperature drop.
- Switch on the heater and set the input with the dimmerstat.
- Wait for steady state, when the temperatures stop changing.
- Record the voltmeter and ammeter readings and all thermocouple temperatures.
- Calculate Q, the resistance of each layer and the overall conductivity.
- Repeat at a second heater setting to check the results.
Key features
- Central 250 mm mica heater with plates on both sides
- Three materials in series: mild steel, bakelite and brass or aluminium
- Thermocouple tappings between layers for the temperature profile
- Multichannel digital temperature indicator
- Dimmerstat with voltmeter and ammeter to set and measure input power
- Frame with Perspex sheet so the assembly can be seen
Documentation and supply
Installation instructions and a manual are supplied with the apparatus. Most Lab Exports products carry a one-year manufacturer warranty.
Lab Exports manufactures the composite walls apparatus at its works in Laxmi Nagar, Delhi, and supplies it to engineering colleges, polytechnics and TVET institutes in India and 60+ countries, handling the export documents for each shipment. More about the company is on the About Lab Exports page.
Related Heat Transfer Lab products
- Heat Pipe Apparatus (EL-HTL-11080)
- Critical Radius of Insulating Material (EL-HTL-11081)
- Pin Fin Apparatus (EL-HTL-11082)
- Natural Convection Apparatus (EL-HTL-11083)
- Forced Convection Apparatus (EL-HTL-11084)
- Specific Heat of Air Apparatus (EL-HTL-11085)
The full range is in the Heat Transfer Lab section of the Engineering Lab range.
Frequently asked questions
What does the composite walls apparatus measure?
It measures the thermal conductivity and thermal resistance of a wall built from mild steel, bakelite and brass or aluminium plates in series.
How is the heater power measured?
A voltmeter and ammeter read the input to the mica heater, which is varied with a 2 A dimmerstat.
What services does the apparatus need?
A 230 V AC stabilised supply with earthing and a bench area of about 1 x 1 m.
What is the price of the composite walls apparatus?
Prices are not published on the website. Add the composite walls apparatus to the Enquiry Cart with the Add To Cart button on this page, or email [email protected] with the house code EL-HTL-11078 and the quantity, to receive a quotation.
Does Lab Exports manufacture the composite walls apparatus?
Yes. Lab Exports manufactures the composite walls apparatus at its works at 11/315, Lalita Park, Laxmi Nagar, Delhi 110092, under house code EL-HTL-11078.
Request a quote
Email [email protected] with the house code EL-HTL-11078 and the quantity, or add the composite walls apparatus to the Enquiry Cart with the Add To Cart button on this page. Tender buyers can also see the Tenders and OEM page.