These density meters were originally designed and intended for measuring homogeneous liquids. In practice, many other samples are measured as well with good success. If the sample viscosity can be brought down to below 36,000 mPa*s by heating at the pumping temperature (e.g. paraffin), density can even be measured automatically with a heated automation unit like the SC1H or SC30H. Samples with higher viscosity can be measured manually if they can be filled into a syringe without trapping air pockets and if the operator can then press these samples out at a controlled speed through a narrow, long tube of about 15 cm in length. Samples which attack the glass U-tube of the measuring cell (e.g. hydrofluoric acid, liquids or pastes used for etching glass) should not be measured with such density meters.