Hydrocarbons) 2 to 200 ppm, threshold Volatile Acids 27 to 2800 mg/L • Zinc 0.01 to 3.00 mg/L hach.com 4 Ordering Information DR 3900 Benchtop Spectrophotometer; includes adapter A for 1 round + AccuVac/1 cm rectangular cuvettes, manual, CD with manual and procedure manual in .pdf ...