Automatic Osmometer

Ultra cooling measurement method
ARKRAY'S unique Ultra Cooling method enables noise-free and accurate measurement.

  • Freezing point depression principle

    1. Sample drawn into measurement cell.

    2. Cooling temperature detection block keeps sample in a liquid state even if temperature falls to freezing point (Ultra Cooling state).

    3. Cooling USC block to below freezing point allows sample to freeze into ice crystals.

    4. Measurement of ice crystal formation temperature in sample and calculation of osmotic pressure based on calibration-based analytical curve.

    5. Heating of temperature sensing block and USC block to melt the sample.

    6. Sample emptied into waste bottle.

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  • Free calibration
    Two-way calibration possible.

    3 point calibration
    Use purified water(0mOsm)and 2 reference solutions(300 mOsm / 1000mOsm)(for when the osmotic pressure of the sample cannot be predicted.)

    2 point calibration
    Use two kinds of solution(LOW/HIGH)with a known osmotic pressure. (Calibration method for when the osmotic pressure of the sample is roughly known.)The smaller the concentration region between "LOW" and "HIGH", the more accurate the data will be.


  • Measurement method


Rack Type Turntable Type
Meas. item Osmotic pressure of body fluid
(Ratio of osmotic pressure)
Sample types Serum, plasma, urine*1
Meas. principle Freezing point depression method using USC system
Meas. range 0‐2000mOsm(Measurement range can be changed
to 0-2500mOsm through use of a switch*2
Meas. accuracy Less than 1% C.V. (200~300 mOsm)
Minimum sample volume Sample cup: 200μL and more Sample cup: 200μL and more
Blood collection tube: 2mL and more
(When urine spitz turntable*3 is used. Urine Spitz: 2mL and more)
Meas. time 2-3 mins / sample
Number of sample set Up to 5 samples Up to 24 samples
(When urine spitz turntable*3 is used.Up to 10 samples)
Calibration method 3 point calibration
(0, 300, 1000mOsm: Piecewise linear approximation), 2 point calibration
Data storage capacity 500 measurement results
Display 24-digit, 2-line, Backlight LCD
Built-in printer 24 space thermal paper
External output Compliant with RS-232C, two-way communication function
(compatibility mode with OM-6050,OM-6040,OM-6030,OM-6020), Ethernet(Option)
Meas. condition Temperature: 10‐30℃
Humidity: 20-80% (with no condensation)
Power input Up to 160 VA
Power supply voltage AC 100 V, 50 / 60 Hz
Dimension 320(W) × 355(D) × 340(H)mm 320(W) × 460(D) × 447(H)mm
Weight Main body: 17kg
Sampler unit: 2kg
Main body: 18kg
Turntable unit: 3kg

This equipment is EMC specification JIS C1806-1:2001 compliant.

*1:We cannot guarantee margin of error for measurement with samples other than serum, plasma and urine.
We adopted the Freezing point depression method as the measurement principle.
For this reason, we use sodium chloride solution as a reference solution for calibration.
Please note that it is possible that some discrepancies in measurement value could arise when using samples that differ from sodium chloride solution in properties such as viscosity.
*2:Please contact us in regard to changes in measurement range.
*3:Urine spitz turntable is a optional product.