EPA Method 1 refers to the procedures for Sample and Velocity Traverses for Stationary Sources

ACCEPTABLE

 Method 1 is the first step towards collection of a representative sample for measuring particulate  concentration and mass emission rate from a stack.  The velocity and particle concentration in the stack are not uniform, so the cross-section must be traversed.  The basic premise is that for straighter lengths of stack or duct, flow streamlines are more uniform and fewer traverse points are needed to obtain a representative sample.  Conversely, the closer the sampling site is to bends and flow disturbances, the more traverse points are needed to obtain a representative sample.  

This method describes procedures to: 

• Select an appropriate(if sample ports do not already exist) 

• Calculate the number of traverse points for velocity and particulate sampling within the stack 

• Calculate the location of the traverse points 

UNACCEPTABLE 

Sampling sites are measured in terms of number of stack or duct diameters away from flow disturbances.  Disturbances can be bends, transitions, expansions, contractions, stack exit to atmosphere, flames or presence of internal installations such as valves or baffles. In figures depicts the relationship of stack diameters and a flow disturbance such as a bend. 

Download Method 1 & Supporting Information