National Physical Laboratory of India users. This process, known as dissemination, is carried out in a number of ways. For applications requiring low levels of uncertainty, there is satellite based dissemination service, which utilizes the Indian national satellite, INSAT. Time is also disseminated through TV, radio, and special telephone services. The caesium atomic clocks maintained at NPL are linked to other such instituted all over the world through a set of global positioning satellites. The unit of electric current, ampere, is realized at NPL by measuring volt and Ohm separately. The uncertainty in measurement of ampere is ± 1 × 10. The standard of temperature
Ampere hour Ampere hour An ampere hour or amp hour (symbol Ah; also denoted A⋅h or A h) is a unit of electric charge, having dimensions of electric current multiplied by time, equal to the charge transferred by a steady current of one ampere flowing for one hour, or 3600 coulombs. The commonly seen "milliampere hour" (mAh or mA⋅h) is one-thousandth of an ampere hour (3.6 coulombs). The ampere hour is frequently used in measurements of electrochemical systems such as electroplating and for battery capacity where the commonly known nominal voltage is dropped. A "milliampere second" (mA⋅s) is a unit of measure