Rocks BarBQue Bar


Weber Smokey Mountain (WSM) Characterization

This is the characterization of a Weber Smokey Mountain (WSM). The cooker is a 19" diameter cylinder with a hemisphere on each end. The height of the chamber is 45.5" for a volume of ~4 cubic feet. The cooker is made of enamel coated steel that is ~.06" thick. I made a couple of additions to the cooker you can see in the pictures. The water pan was replaced with a clay pot base. Sensor Grommets were added to feed the Temperature Sensors leads through.

Two Temperature Sensors were placed in the cooker as shown in the picture to the right. One Sensor was placed in the center of the bottom cooking grill about 2" from the surface. One Sensor was placed in the center of the top cooking grill about 2" from the surface.The Temperature Sensor in the top is the control Sensor for the 5cfm blower and is set to 240 deg f. A third sensor is mounted near the Stoker to record the ambient temperature.

To do a characterization that can be repeated and have comparable results you have control as many variables as possible. Since I am not cooking food, charcoal briquettes is a good choice for fuel. The briquettes consistent uniformity makes them a good choice for comparing one characterization to another. The briquettes I use are the new Kingsford brand.

I place 50 unlit briquettes in the fire box. I put 50 more briquettes in a chimney starter with 2 sheets of newspaper. After 15 minute the briquettes are ashed over and dumped on the 50 unlit briquettes in the fire box. Both doors are closed and remain closed for the duration of the characterization.

The control algorythem used for control was on-off

Burn time in temperature range = 7 hrs Average top temperature = 240.6 Average bottom temperature = 230.8

Weber Smokey Mountain (WSM)

Weber Smokey Mountain (WSM)

WSM with 2 Temperature Sensors

Two Temperature Sensors placed inside the cooking chamber.

WSM UnlitWSM Lit

Fifty unlit briquettes (left) Plus fifty lit briquettes (right)


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