Hach DPD free chlorine reagent powder pillows for spectrophotometric and colorimetric determination of free chlorine (hypochlorous acid and hypochlorite ion) in water, treated waters, estuary and seawater. USEPA DPD Method 8021 (DOC316.53.01023), range 0.02-2.00 mg/L Cl₂. USEPA accepted for reporting for drinking water analyses. 25 mL sample volume, pack of 100.
| Part | DPD-F-100PK |
| Method | DPD colorimetric |
| Range | 0.02-2.00 mg/L |
| Accuracy | ±3% |
| Vials | 25 per pack (standard) / 100 per pack (chlorine pillows) |
| Required equipment | Hach DR-series photometer / spectrophotometer + DRB200 heater (digestion tests) |
| MOQ | 1 |
All TNTplus vials use 16mm test-tube format with auto-recognition barcode on DR900/1900/6000.