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Article No.: A0006AC
Articlename: K-7400S Semi-Micro Osmometer

Freezing point osmometer

for the determination of osmolality or freezing point of aqueous solutions

KNAUER is one of the pioneers in the field of osmometry and known for its reliable and user friendly instruments for many decades.

Our freezing point osmometer K-7400S allows the easy and fast determination of the osmolality of various aqueous solutions. Also, the freezing point depression of the samples can be read. The proven technology of freezing point determination in combination with the robust and intelligent design of the device allows reproducible measurements. The instrument is equipped with a peltier cooler and an integrated microprocessor controlling the automated measurement. The freezing point osmometer is a standalone device that optionally can be equipped with a printer. Furthermore, the device can be controlled via the EuroOsmo 7400 software. The software automatically plots the temperature curve for each measurement and calibration and allows saving of the measured values. In addition, the data can optionally be exported into various file formats for archival storage.

The measurement specifications of the KNAUER Semi-Micro Osmometer K-7400S comply with the requirements of the European Pharmacopoeia for osmolality (Ph. Eur. 2.2.35, 10/2021) in the pharmaceutically relevant range of 0 to 400 mOsmol/kg.


Scope of delivery:

  • Freezing Point Osmometer K-7400S incl. 150 µl measuring head for plastic sample tubes (A0840-2)
  • Power cable
  • RS-232 connection cable
  • 500 Pack of sample tubes (A0272)
  • 400 mOsmol/kg calibration solution (A01241-1)
  • 850 mOsmol/kg calibration solution (A01250)
  • Pack of lint-free cleaning tissue (A02330)



More information about osmometry here

Key Features

Technical Data

Technical parameters

Sample volume 150 µl (50 µl when using measuring head A0840-4)
Osmolality range 0 - 2000 mOsmol/kg
Resolution osmolality: integer value without decimal part, e.g. 850 mOsmol
temperature: value with three digits, e.g. -1.576 °C
Test time ~ 2 min
Precision SD ≤ 4 mOsmol/kg [0 — 400 mOsmol/kg]
RSD ≤ 1 % [400 — 2000 mOsmol/kg]
Linearity ± 1 % [0 -1500 mOsmol/kg]
± 1.5 % [0 - 2000 mOsmol/kg]
Calibration Two-point calibration (0 mOsmol/kg and one freely selectable osmolality)
optional: Three-point calibration (0 Osmol/kg and two freely selectable osmolalities)


Interfaces RS-232 port
Control Keypad (LED display, 2 rows with 24 characters)
optional: EuroOsmo7400 Software


Power supply 100 – 240 V, 50 – 60 Hz, 70 W
Dimensions 160 x 182 x 340 mm (W x H x D)
Weight 5.3 kg
Ambient conditions Temperature range: 10–35 °C
Rel. humidity: 20–80 % (non-condensing)
Note The 150 µl measuring head A0840-2 is included in the scope of delivery of the device. For sample volumes of 50 µl, the measuring head A0840-4 should be used and must be ordered separately.

Documents and more information

Certified Quality 

KNAUER is known for the quality of its products and has been certified several times. We produce high-tech laboratory instruments for research, routine analysis and production.
See all Quality certificates

In addition, we have extended documentation about all our products, including CE Declarations of Conformity.
See all CE Declarations of conformity

Innovation and quality - since 1962. Made in Germany.

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Technical data or prices are subject to change without notice. Prices may vary by country and do not include taxes, customs duties or delivery. All trademarks are the property of their respective owners.Our general terms and conditions apply: www.knauer.net/terms

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