Hanna Instruments HI-762 Ultra Low Range Free Chlorine Checker®HC Colorimeter (0 to 500 ppb)

The Hanna Instruments HI-762 Ultra Low Range Free Chlorine Checker®HC bridges the gap between simple chemical test kits and professional instrumentation. Chemical test kits rely on the human eye to discern colour differences, limiting their accuracy and resolution. Professional instrumentation offers greater precision but at significant cost. The HI-762 uses a fixed wavelength LED at 525 nm and a silicon photodetector to deliver the accuracy of professional instrumentation at an accessible price — measuring free chlorine across an ultra low range of 0 to 500 ppb with 1 ppb resolution.

The HI-762 uses an adaptation of USEPA method 330.5, DPD Method. 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. Chlorine is the most commonly used water disinfectant and regular, accurate monitoring at ultra low levels is essential wherever precise dosing control is required. The HI-762 is supplied with two sample cuvettes, a cuvette cap, a starter pack of 6 reagent tests, a battery and instructions. Replacement reagents are available as HI-762-25 (25 tests).

Key Features

• Ultra low range free chlorine measurement 0 to 500 ppb with 1 ppb resolution
• Accuracy ±4% of reading ±20 ppb @ 25°C
• Fixed wavelength LED @ 525 nm with silicon photodetector — professional accuracy at an affordable price
• More accurate than chemical test kits — no colour-matching guesswork
• Contoured palm-sized design with large, easy to read LCD
• Auto shut-off after 10 minutes of non-use
• 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

Please note: Interference may be caused by the following — bromine, chlorine dioxide, iodine, oxidised manganese and chromium, and ozone (all positive errors). Alkalinity above 1,000 mg/L CaCO₃ (as bicarbonate) or above 25 mg/L CaCO₃ (as carbonate) and acidity above 150 mg/L CaCO₃ may cause colour to develop incompletely or fade rapidly — neutralise with diluted HCl or NaOH respectively. For water with hardness greater than 500 mg/L CaCO₃, shake the sample for approximately 2 minutes after adding the powder reagent.