Abstract: Laboratory equipment for practicing experiments and mixing ozone with medium consistency cellulosic pulp allows precise control of the timing and amount of ozone injected into the mixer, providing a method of testing that is more accurate than prior methods. An injection cylinder and fluidizing laboratory mixer are utilized. Pulp is fed into the mixer, the cylinder is charged with a known predetermined amount of ozone containing gas, the ozone containing gas is injected from the cylinder into the mixer, the mixer is operated to effect mixing of the ozone containing gas with the pulp for a predetermined period of time, and then gas containing residual ozone (which has not reacted with the pulp) from the mixer is vented from the mixer, including by utilizing a purge gas such as nitrogen. The ozone is created by an ozone generator which continuously operates. A three-way valve directs the output of the ozone generator to an ozone destruction device when the ozone is not being charged into the cylinder.