A tube diffusion dosimeter for sulfur dioxide.

A tube type diffusion dosimeter was developed for sulfur dioxide. The dosimeter can be fabricated by the user from inexpensive, easily available materials. The design incorporates a tube diffusion element, liquid absorption reservoir and a porous plastic mass transfer element. The design was verified by exposure chamber tests using constant and fluctuating gas concentrations. Field testing was conducted using a NIOSH bubbler method for comparison. Laboratory and field tests confirmed that the dosimeter was reliable for sulfur dioxide concentrations between 2.5 and 15 ppm. However, to retain accuracy, exposed dosimeters require refrigeration and laboratory analysis within 24 hours after use.