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Hanna HI-97735 Total Hardness Portable Photometer


HI-97735 is an advanced portable photometer for the measurement of Total Hardness. 


£490.50 (exc.VAT)
£588.60 (tax incl.)
Order now for 2 weeks delivery
Full Description Specification Manuals

This meter offers a superior optical system that utilises a reference detector and narrow band interference filters for extremely fast and repeatable measurements. Comes with: sample cuvette x 2, sample cuvette cap x 2, plastic stopper x 2, 1.5V AA Alkaline batteries, instrument quality certificate, instruction manual.

  • No warm up time before taking a measurement
  • Tutorial mode for step-by-step instructions

The HI-97735 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 customising the meter to user preferences.

HI-97735 is waterproof including the cuvette holder that is designed with ridges to protect the optical path from getting scratched by the cuvette and a protected battery compartment that holds three 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.

Advanced LED optical system

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.


Validate the performance of the instrument at any time and apply a user calibration using CAL Check cuvettes made with NIST traceable standards.

The CAL Check screen guides the user step-by-step through the validation process and user calibration.

On-screen tutorial mode with animations

The built in tutorial mode guides users step-by-step through the measurement process.

Auto logging

Waterproof and floating IP67 case


Review of the last calibration date.

Auto-shut off

Automatic shut off after 15 minutes of inactivity and 30 minutes before a read measurement.

Battery status indicator

Indicates the amount of battery life left.

Built-in timer

Display of time remaining before a measurement is taken. Ensures that all readings are taken at the appropriate reaction intervals for the test being performed.

Error messages

Messages on display alerting to problems including no cap, high zero, and standard too low.

Units of measurement

Appropriate unit of measure is displayed along with reading.

About Total Hardness

Water, with exception to distilled water, contains dissolved salts (magnesium and calcium carbonates). The concentration of these salts determines the water hardness, which can be expressed in calcium carbonate or magnesium carbonate. The sum of these two represents the total hardness level. In addition, water hardness is also related to the phenomenon of pipe rusting in water heating and cooling systems, reverse osmosis, and demineralisation plants.

Read More

 Range 0 to 250 mg/L (as CaCO3)
 Resolution 1mg/L
 Accuracy @ 25°C ±5mg/L ±4% of reading at 25°C
 Method Adaptation of the EPA recommended method 130.1
 Range 200 to 500 mg/L (as CaCO3)
 Resolution 1mg/L
 Accuracy @ 25°C ±7mg/L ±3% of reading at 25°C
 Method Adaptation of the EPA recommended method 130.1
 Range 400 to 750 mg/L (as CaCO3)
 Resolution 1mg/L
 Accuracy @ 25°C ±10mg/L ±2% of reading at 25°C
 Method Adaptation of the EPA recommended method 130.1
 Light Source Light emitting diode
 Bandpass filter 466nm
 Bandpass filter bandwidth 8nm
 Bandpass filter wavelength accuracy ±1.0nm
 Light detector Silicon photocell
 Cuvette type Round 24.6mm diameter (22 mm inside)
 Auto logging 50 readings
 Display 128 x 64 pixel B/W LCD with backlight
 Auto off After 15 minutes of inactivity (30 minutes before a READ measurement)
 Battery type/life Alkaline 1.5 V AA (3) / > 800 measurements (without backlight)
 Environment 0 to 50°C; 0 to 100% RH, non-serviceable
 Dimensions 142.4 x 102.5 x 50.5 mm
 Weight 380g
(sold separately)
HI-97735-11CAL Check standard cuvettes for total hardness LR, MR, HR
HI-93735-00Hardness LR reagent (100 tests)
HI-93735-01Hardness MR reagent (100 tests)
HI-93735-02Hardness HR reagent (100 tests)
HI-93735-0Reagents for 300 tests (LR- 100 tests, MR – 100 tests, HR – 100 tests)