Blow off method is most popular in the measurement of specific toner charge. Toner is charged with mixing with carrier in rotating cylinder and the measurements of the specific toner charge are carried out on the various blowing off pressure 2KPa – 20KPa. From the measured specific toner charge and the blow off toner amount dependence on blow off pressure, the specific toner charge distribution is estimated. The data is compared with the data by E-SPART measurement and reasonable agreement is obtained between them.
R. Ohtsuka, T. Fujita, K. Konnai, Y. Hoshino, "Measured Specific Toner Charge Dependence on Suction Pressure in Blow off Method" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP17), 2001, pp 860 - 863, https://doi.org/10.2352/ISSN.2169-4451.2001.17.1.art00096_2