For determination of Low Range Ammonia Nitrogen by the AmVerâ„¢ Salicylate Test 'N Tubeâ„¢ Method. Hach Method 10023. Range: 0.02 - 2.50 mg/L NH3-N. Reagent set contains: AmVer Diluent Reagent Low Range Test 'N Tubes, Ammonia Salicylate. Reagent Powder Pillows and Ammonia Cyanurate Reagent Powder Pillows. 25-50 tests (dependent upon the number of reagent blank tests performed) Test 'N Tube products provide safe, convenient testing Easy ordering