YSI 900 Chlorine Colorimeter

The YSI 900 Chlorine Colorimeter is a rugged, waterproof, single-parameter instrument for the measurement of total chlorine or free chlorine.


  • Automatic data storage; 16 data-sets with date and time stamp
  • User-calibration to any government or organizational standard (N.I.S.T. or ISO)
  • IP68 waterproof case; easy to hold or set on benchtop; floats
List Price $494.50
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YSI 900 Chlorine Colorimeter

The YSI 900 Chlorine Colorimeter is a rugged, waterproof, single-parameter instrument for the measurement of free or total chlorine. Whether measuring chlorine in wastewater, chlorine in groundwater, or in pools, the YSI 900 Chlorine Colorimeter is waterproof with an easy-to-read display and provides readings in minutes.

The instrument features a real-time clock, automatic data logging as well as the ability to export data to a PC or printer using the 900 Series Data Hub for infrared data transfer. The YSI 900 includes a hard-sided carrying case with compartments for the instrument, accessories, reagents, and more.


  • Automatic data storage; 16 data sets with date and time stamp
  • Large, backlit LCD display
  • IP68 waterproof case; easy to hold or set on a benchtop; floats
  • Innovative light shield avoids moving parts or separate pieces that can easily be broken or lost
  • User calibration to any government or organizational standard (for example, N.I.S.T. or ISO)
  • Resolution can be improved for specific range requirements
  • Known interferences can be adjusted for the sample
  • Auto shutoff extends battery life
  • Power Supply: 4 alkaline AAA batteries; approximately 17 continuous hours or 5,000 tests
  • Auto Shutoff: 20 minutes after last key press; audible signal
  • Operating Range: 5° to 40°C (41° to 104°F); 30-90% relative humidity
  • Display: Backlit LCD
  • Memory Capacity: 16 data sets with date and time stamp; automatic
  • Weight: 260 g (0.5 lbs)
  • Dimensions: 15.9 L x 7.6 W x 3.8 H cm (6.1 L x 3 W x 1.5 H in)
  • Interfaces: Infrared interface with the 900 Series Data Hub (optional) for data transfer
  • Operation: Acid/solvent resistant case; touch-sensitive keypad with audible feedback; factory calibrated; user calibration possible; reset to factory cal
  • Certifications: CE; IP68 waterproof rating (1 hour at 0.1 meter); floats
  • Colorimetric Resolution: 0.01 A (absorbance)
  • Photometric Accuracy: 3% FS (T = 20° to 25°C) (68° to 77°F)
  • Wavelength Accuracy: ±1 nm
  • Warranty: 1 year
  • Optics: LEDs, interference filter (IF) and photo sensor in a transparent chamber. 1 interference filter
  • Wavelength Range: 530 nm IF Δ λ = 5 nm
  • (1) 900 chlorine colorimeter
  • (100) Free chlorine powder packs
  • (100) Total chlorine powder packs
  • (1) Waterproof carrying case
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