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Properties of Liquids

Working Group 3.32

Newtonian calibration liquids for viscosity

Newtonian calibration liquids for viscosity are liquids traceable to the National Standard of viscosity (formerly referred to as "reference standard oils"). They are used for calibration or testing of viscosity measuring devices. Viscosity measuring devices calibrated or tested with these liquids are traceable to the National Standard of Viscosity and comply with the requirements of DIN EN ISO/IEC 17 025.

Liquids used for calibration meet special requirements, e.g., for flow behavior and long-term stability of the viscosity value. With respect to dissolved gases, they are in equilibrium with the atmosphere.

The relative uncertainty of the viscosity for calibration liquids provided by the Physikalisch-Technische Bundesanstalt is 0.2 % to 1 % of their value. These calibration liquids are mainly used for calibrating or verification of high-accuracy viscometers, e.g., capillary or falling sphere viscometers, which are used as internal standard of an enterprise to calibrate or verify its own visosity measuring devices or to carry out high-precision measurements.

With regard to the measuring ranges of common viscometers, PTB offers an extensive range of Newtonian calibration liquids with viscosities in the range from 1.2 mm2/s to 775 000 mm2/s. A detailed overview is provided in the tables below. Their kinematic viscosity is determined using viscometers of the National Standard of Viscosity, which is based on the kinematic viscosity of water at 20 °C of ν = 1.0034 mm2/s (internationally agreed value in accordance with ISO/TR 3666-1998 and  subject to ITS-90). The dynamic viscosity is calculated by means of the density determined with calibration standards for liquid density traceable to the National Standard of the Unit of Density.

A calibration certificate from the Physikalisch-Technische Bundesanstalt is supplied with the calibration liquids. This specifies the kinematic and dynamic viscosity as well as the viscosity-temperature coefficient at the respective temperature, usually 20 °C. On request, these values can also be determined for other temperatures in the range from 20 °C to 100 °C, preferably for 23, 25, 40 and 100 °C. They are valid for a period of 6 months provided that the bottle with the standard sample is kept unopened, in the dark and at room temperature.

We will be pleased to provide you with a current quotation.

Newtonian viscosity calibration liquids are also provided by accredited calibration laboratories. Calibration certificates of the accredited calibration laboratories document the traceability to national standards (realized by PTB) for the representation of units in accordance with the International System of Units (SI).

 

 

Table 1a: Benchmark of the dynamic viscosity for the calibration liquids offered

Calibration fluid

dynamic viscosity in mPa s at

Uncertainty

(%)

20 °C23 °C25 °C40 °C100 °C
2A1.51.41.31.0-0.2
4A2.92.72.61.9-0.2
10A9.68.78.15.2-0.2
20A2017169.12.20.2
50B574843223.80.25
100A1028778396.10.25
500A380320280130150.28
1000A1100890780330320.28
2000A170014001200490440.28
5000A3800310027001000780.35
10000A7900600050001500590.38
20000A19000140001200038001500.45
50000A4500037000320001300011000.5
100000A950006800057000150003900.7
200000A230000170000140000380009500.8
500000B70000052000043000012000027001.0

 

 

Table 1b: Benchmark of the kinematic viscosity for the calibration liquids offered

Calibration fluid

Kinematic viscosity in mm²/s at

Uncertainty

(%)

20 °C23 °C25 °C40 °C100 °C
2A1.91.81.71.4-0.2
4A3.73.53.32.5-0.2
10A1211106.5-0.2
20A232019112.70.2
50B665650254.70.25
100A12210494487.90.25
500A450380340150190.28
1000A13001100930390400.28
2000A200016001400590550.28
5000A4500360032001200970.35
10000A9000690057001700710.38
20000A21000160001400043001800.45
50000A530004400038000150001300

0.5

100000A1060007600064000170004600.7
200000A2500001900001600004200011000.8
500000B78000058000048000013000032001.0

 

 

The costs are charged in accordance with the Opens external link in new windowGeneral Terms and Conditions, the
Opens external link in new windowcurrent price list of the Physikalisch-Technische Bundesanstalt and according to the amount of work required for viscosity and density determination, provision and delivery of the calibration liquids. They depend on the viscosity and the quantity delivered. Shipping costs are charged. At the request of the customer, the shipment can also be made freight collect with the parcel service requested by the customer.

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