International Standard for viscosity at temperatures up to 473 K and pressures below 200 MPa (IUPAC Technical Report)
Abstract This paper presents the results of an investigation into possible liquid viscosity standards to meet an industrial requirement for a liquid with a nominal viscosity of 20 mPa s at a temperature of 473 K and pressure of 200 MPa with a relative expanded uncertainty of less than 5%. There are no commercially available certified viscosity reference liquids that meet this requirement. Four candidate fluids were examined: squalane, Krytox GPL102, tris(2-ethylhexyl) trimellitate (TOTM), and dipentaerythritol hexa(3,5,5-trimethylhexanoate) (DiPEiC9). Although none of these fluids satisfies all of the criteria, two fluids were identified as being suitable as International Standards for viscosity at temperatures up to 473 K and pressures below 200 MPa. These fluids are squalane and tris(2-ethylhexyl) trimellitate (TOTM), which at T=473.15 K and p=200 MPa present viscosity values of 5 mPa s and 10 mPa s, respectively.