Hanna Instruments HI-3875 Free Chlorine test kit
Chlorine is the most commonly used water disinfectant in applications that vary from treatment of drinking water and wastewater, pools and spas sanitization, to food processing and sterilization. DPD method. Range (0.0-3.5 mg/L).
The HI-3875 free chlorine, medium range test kit is equipped with all you need to determine free chlorine levels in water. Free chlorine reacts with ammonium ions and organic compounds to form chlorine compounds resulting in diminished disinfecting capabilities compared with free chlorine. These chlorine compounds together with chloramines form combined chlorine. Combined chlorine and excess free chlorine together result in total chlorine. While free chlorine has a much higher disinfectant potential, combined chlorine has a much higher stability and has a lesser volatility. There should be sufficient levels of unreacted free chlorine for adequate disinfection, but not so much as to become harmful.
Order information
The HI-3875 free chlorine, medium range test kit comes supplied with; HI-93701-0 free chlorine reagents (100 pack), 500mL deionised water, checker disc, glass vials with caps (2) and 3mL plastic pipette.
Specifications
| Method | Checker Disc |
| Range | 0.0-3.5 mg/L |
| Smallest Increment | 0.1 mg/L |
| Chemical Method | DPD |
| Number of Tests | 100 |
| Weight | 984 g |
Downloads
Frequently Asked Questions
Clear answers to help you choose the right water testing solution with confidence
Which brands of water testing kits do you supply?
Do you provide kits for both home and professional use?
Yes — whether you’re a pool or spa owner, aquarium keeper, utility company, or a university laboratory, we have the right solution for your needs.
Can I arrange servicing or calibration for my photometer?
Absolutely. We also provide servicing and calibration to keep your photometers accurate and reliable.
How quickly do you dispatch orders?
Orders placed before 2:30 pm (Monday–Friday) are dispatched the same day. We also ship on Saturdays for your convenience.
Which couriers do you use for delivery?
We deliver through UPS, DPD, and Royal Mail. You can also choose to upgrade to next-day delivery at checkout.
What is your return policy?
We accept returns within 14 days of delivery provided the items are unused, in their original packaging, and in resalable condition. Please contact our team before returning any items.
Can I place bulk or business orders?
Yes, we welcome bulk, trade, and institutional orders. For tailored pricing or large quantities, please get in touch with us directly.
How can I get help if I’m unsure which kit to buy?
You can call us at 📞 +44 (0)115888 2726 and our team will guide you in choosing the most suitable kit for your needs.