What type of calorimeter is junkers caloriemeter?

A Junkers Calorimeter is a device for determining the heating capacity of a gas - that is, how many joules one can get by burning a set volume of that gas. It's usually [natural] gas from the mains, but could be any flammable gas.

The device is essentially a Bunsen burner with a cooling jacket. The jacket is cylindrical in shape, about 80cm tall, with water running through it. The burner sits inside the cylinder. The calorimeter allows the user to measure the temperature of water flowing in and flowing out. Once steady-state is reached, with those two temperatures steady, the water flowing through is collected for a specified period of time. Measuring the mass of the water and the temperature rise in the water, the operator can calculate the number of joules which went into the water to heat it. There is a flow meter on the fuel gas, so the operator can also calculate the volume of gas that was burned in the same time period. The amount of energy, in J, available per litre of gas can then be calculated.

A Junkers calorimeter is a flow calorimeter, with heat transfer happening continuously, as opposed to a batch calorimeter.

The design dates back to the late 1800s.