What are calorimeters made of?
A calorimeter is simply a container with insulating walls.
In essence, it is a device in which the temperature before and after some kind of change can be accurately measured.
It is made so that no heat can be transferred between the calorimeter and its surroundings.
Probably the simplest of such devices is the coffee cup calorimeter.
The Styrofoam coffee cup is a relatively good insulating material.
A lid cardboard or other material also helps to prevent loss of heat, and a thermometer measures the change in temperature.
Even expensive devices like bomb calorimeters that are used to measure heats of combustion operate on the same principle.
They consist of a strong-walled metal container set inside another container filled with water.
The inner container has an opening through which oxygen can be introduced and electrical leads to start the combustion. Temperatures are recorded automatically.
There are many types of calorimeters, but they are all basically variations on the simple coffee cup.