In the United States, the inflation rate is most commonly measured by the percentage rise in the Consumer Price Index, which is reported monthly by the Bureau of Labor Statistics (BLS). A CPI of 120 in the current period means that it now takes $120 to purchase a representative basket of goods that $100 once purchased.
Paraphenylenediamine (PPD) is a chemical substance that is widely used as a permanent hair dye. It may also been found in textile or fur dyes, dark coloured cosmetics, temporary tattoos, photographic developer and lithography plates, photocopying and printing inks, black rubber, oils, greases and gasoline.
IPD is also used to describe the distance between the exit pupils or optical axes of a binocular optical system. Pupillary distance (PD) also describes the distance between the two pupils, but is an optometric term used to specify prescription eyewear. The PD of a patient is used to specify prescriptive eyewear for that patient. The distinction with IPD is the importance of anthropometric databases and the design of binocular viewing devices with an IPD adjustment that will fit a targeted population of users.