Hanna Instruments HI-701 Free Chlorine Checker®HC Handheld Colorimeter (0.00 to 2.50 ppm)

The Hanna Instruments HI-701 Free Chlorine Checker®HC is a compact, palm-sized handheld colorimeter for quick and accurate measurement of free chlorine across a range of 0.00 to 2.50 ppm. Chlorine is the most commonly used water disinfectant and regular, accurate monitoring is essential to avoid serious health and safety risks. The HI-701 delivers high precision results in a simple, portable format that is more accurate than chemical test kits, with no colour-matching guesswork required.

The HI-701 uses an adaptation of USEPA method 330.5 — the reaction between free chlorine and the DPD reagent produces a pink tint in the sample which the Checker®HC measures and displays as a digital ppm value. The contoured casing is designed to fit comfortably in the palm of the hand, the large LCD is easy to read, and the auto shut-off feature ensures the battery cannot be drained if the unit is left on. The HI-701 is supplied with two sample cuvettes, a cuvette cap, a starter pack of reagents (6 tests), a battery and instructions. Replacement reagents are available as HI-701-25 (25 tests).

Key Features

• Free chlorine measurement range 0.00 to 2.50 ppm (mg/L)
• Precision ±3% of reading ±0.03 ppm @ 25°C
• More accurate than chemical test kits — clear digital readout
• LED light source @ 525 nm with silicon photocell detector
• Contoured palm-sized design with large, easy to read LCD
• Auto shut-off after 2 minutes of non-use and after read
• Fully portable — fits easily in palm and pocket
• Single AAA battery powered
• Supplied with starter pack of 6 reagent tests

Typical Applications

• Swimming pools and spas
• Fruit, vegetable and salad washing
• Disinfection monitoring
• Aquaculture
• Fish tanks — use alongside recommended dechlorinators

Please note: Interference may be caused by bromine, iodine, ozone and oxidised forms of chromium and manganese. For water with hardness greater than 500 mg/L CaCO₃, shake the sample for approximately 2 minutes after adding the powder reagent. If alkalinity exceeds 250 mg/L CaCO₃ or acidity exceeds