What is PRIMARY TIME STANDARD? What does PRIMARY TIME STANDARD mean? PRIMARY TIME STANDARD meaning - PRIMARY TIME STANDARD definition - PRIMARY TIME STANDARD explanation.<br /><br />In telecommunications, a primary time standard is a time standard that does not require calibration against another time standard.<br /><br />Examples of primary time, (i.e., frequency standards) are caesium standards and hydrogen masers.<br /><br />The international second is based on the microwave frequency (9,192,631,770 Hz) associated with the atomic resonance of the hyperfine ground state levels of the caesium-133 atom in a magnetically neutral environment.<br /><br />Realizable caesium frequency standards use a strong electromagnet to deliberately introduce a magnetic field which overwhelms that of the Earth. The presence of this strong magnetic field introduces a slight, but known, increase in the atomic resonance frequency. <br /><br />However, very small variations in the calibration of the electric current in the electromagnet introduce minuscule frequency variations among different caesium oscillators.
