Free Chlorine Portable Photometer with CAL Check – HI97701

HI97701 is an advanced portable photometer for the measurement of free chlorine in water. This meter offers a superior optical system that utilizes a reference detector and narrow band interference filters for extremely fast and repeatable measurements.

  • CAL Check to verify meter performance
  • Tutorial mode for step-by-step instructions
  • Choice of powder or cost saving liquid reagents



Chlorine is a common chemical used by many due to is disinfection, oxidation and bleaching properties. In swimming pools, drinking water, and food processing chlorine is used to disinfect and keep bacteria from growing. In metal finishing it used as an oxidizer to convert cyanide in wastewater to cyanate while in the pulp and paper industry it used to bleach wood pulp so that paper is white. The HI97701 is designed to measure free chlorine in water up to 5.00 mg/L (ppm).

The HI97701 has an innovative optical system that offers superior performance in accuracy, repeatability, and the short amount of time it takes to perform a measurement. This compact, waterproof meter is extremely user friendly with a tutorial mode that walks the user graphically, step by step, in performing a measurement. 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.

HI97701 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. The LCD is 71 mm (2.75″) by 37 mm (1.6″) and is backlit for easy viewing under all conditions


Stable Light Source:

  • The internal reference system of the HI97701 photometer 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:

  • Hanna’s exclusive CAL Check feature allows for performance verification and calibration of the meter using NIST traceable standards. Our CAL Check standard vials are developed to simulate a specific absorbance value at each wavelength to verify the accuracy of subsequent readings.


Multitple 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 users.


Large Cuvette Size:

  • The sample cell of the HI97701 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 HI97701 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


SKU: HI97701-web

Product Name: Free Chlorine Portable Photometer with CAL Check HI97701

Quote Required: Yes

Free Chlorine Range: 0.00 to 5.00 mg/L (as CI2)

Free Chlorine Resolution: 0.01 mg/L

Free Chlorine Accuracy: ±0.03 mg/L ±3% of reading

Chlorine Method: adaptation of the EPA 330.5 DPD method

Photometer/Colorimeter Light Source: Light emitting diode with narrow band interference filter @ 525 nm

Photometer/Colorimeter Light Detector: silicon photocell

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: 1.5V AA battery (3 pcs.)/ > 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

Weight: 380 g (13.4 oz.) with batteries

Dimensions: 142.5 x 1025 x 50.5 mm (5.6 x 4.0 x 2.0″)

Ordering information: HI97701 is supplied with cuvettes (2), caps (2), plastic inserts for cuvettes (2), 1.5V AA batteries (3), instruction manual, and instrument quality certificate.

Kit: HI97701C is supplied with CAL-Check standards, cuvettes (2), caps (2), plastic inserts for cuvette, (2), scissors, cuvette cleaning cloth,1.5V AA batteries (3), instruction manual, and instrument quality certificate.

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