Here's an EPA document which shows some pictures, look at page 2 for the unit the OP has. http://www.epa.gov/mercury/pdfs/EPA-905-F-11-008.pdf http://www.epa.g

Here's an EPA document which shows some pictures, look at page 2 for the unit the OP has. http://www.epa.gov/mercury/pdfs/EPA-905-F-11-008.pdf http://www.epa.gov/mercury/pdfs/EPA-905-F-11-008.pdf