HI97771 is an advanced portable photometer for the measurement of free and ultra high range total chlorine in water. HI97771 is designed to measure very high concentrations, 500 mg/L (ppm), of total chlorine in water, and free chlorine up to 5.00 mg/L (ppm). This meter offers a superior optical system that utilizes a reference detector and narrow band interference filters for extremely fast and repeatable measurements. The use of a backlit dot matrix LED allows the use of virtual keys which makes the operation of the meter very intuitive including selecting different methods, reviewing GLP data, recalling the last 50 measurements, and customizing the meter to user preferences. This photometer is completely waterproof including the cuvette holder that is designed with ridges to protect the optical path from getting scratched by the cuvette and a gasketed battery compartment that holds three common AA batteries. The compact design fits comfortable in the hand for use in the field or on a table for benchtop use.




  • Stable Light Source - The internal reference system compensates for any drifts due to power fluctuations or ambient temperature changes. With a stable source of light the readings are fast and stable between your blank (zero) measurement and sample measurement.
  • High Efficiency Light Source - LED light sources offer superior performance compared to tungsten lamps. LEDs have a much higher luminous efficiency, providing more light while using less power. They also produce little heat, which could otherwise affect electronic stability. 
  • High Quality Filters - Improved optical filters ensure greater wavelength accuracy and allow a brighter, stronger signal to be received. The end result is higher measurement stability and less wavelength error.
  • Greater Light Yield - A focusing lens collects all of the light that exits the cuvette, eliminating errors from imperfections and scratches that may be present in the glass. The use of the convex lens reduces the need for indexing cuvettes. 
  • CAL Check Functionality - The exclusive CAL Check feature allows for performance verification and calibration of the meter using NIST traceable standards. The CAL Check standard vials are developed to simulate a specific absorbance value at each wavelength to verify the accuracy of subsequent readings.
  • Mulitple Measurement Methods - Users can select the use of powder reagents supplied in packets or the use of low cost liquid reagents supplied in a dropper bottle.
  • Built-in Reaction Timer - Waiting the proper reaction time is of key importance when performing colorimetric measurements. The countdown timer displays the time remaining until a measurement will be taken, ensuring consistent results between sample measurements and user
  • Large Cuvette Size - The sample cell of the HI97771 fits a round, glass cuvette with a 25 mm path length. The relatively long path length of the sample cuvette allows the light to pass through more of the sample solution, ensuring accurate measurements even in low absorbance samples.
  • Intuitive Dot Matrix Display - The HI97771 is designed with a backlit, graphic LCD. With virtual keys, a battery status indicator, and error messages. Users will find the meter interface intuitive and easy to read. A dedicated help key provides information relating to the current meter operation, and can be used at any stage in the setup or measurement process to show contextual help.
  • Auto-off Protection - The meter uses three common AA batteries that allow for about 800 measurements to be taken. The auto-off feature automatically shuts off the meter after 15 minutes of inactivity in order conserve battery life.

Free & UHR Total Chlorine Portable Photometer

SKU: HI97771C
  • Free Chlorine Range: 0.00 to 5.00 mg/L (as Cl2)
  • Free Chlorine Resolution: 0.01 mg/L
  • Free Chlorine Accuracy: ±0.03 mg/L ±3% of reading
  • Total Chlorine Range: 0 to 500 mg/L (as Cl2)
  • Total Chlorine Resolution: 1 mg/L
  • Total Chlorine Accuracy: ±3 mg/L ±3% of reading
  • Chlorine Method:
    • Free chlorine: adaptation of the EPA 330.5 DPD method
    • Total chlorine: adaptation of the Standard Methods for Examination of Water and Wastewater, 20th edition, 4500-Cl.
  • Light Source: Light emitting diode
  • Light Detector: silicon photocell with narrow band interference filter @ 525 nm
  • Bandpass Filter Bandwidth: 8 nm
  • Bandpass Filter Wavelength Accuracy: ±1.0 nm
  • Cuvette Type: round, 24.6 mm diameter (22 mm inside)
  • GLP: date, time of last calibration
  • Display: 128 x 64 pixel B/W LCD with backlight
  • Logging Type: automatic logging
  • Logging Memory: 50 measurement
  • Battery Type/Life: 3 (1.5V) AA battery / > 800 measurements (without backlight)
  • Automatic Shut-Off: after 15 minutes of inactivity (30 minutes before a READ measurement)
  • Environment: 0 to 50°C (32 to 122°F); relative humidity: 100% (IP67)

28 Vaughan Road

Welland, ON, L3B 5Y1

Mon-Thurs 9-5, Fri 9-4:30

Closed Sat & Sun

© 2019 Water Concepts


P: 905-788-1784

F: 905-788-3456

*Phone is regularly monitored after-hours