Ask your doctor for a vitamin D test. Be specific and ask for a 25(OH)D test. There is another type of blood test for vitamin D, called a 1,25(OH)âD test, but the 25(OH)D test is the only one that will tell you whether youâre getting enough vitamin D. Order an in-home test. These tests are sent to your home.
Carrier signal: A frequency in a communications channel modulated to carry analog or digital signal information. For example, an FM radio transmitter modulates the frequency of a carrier signal and the receiver processes the carrier signal to extract the analog information. An AM radio transmitter modulates the amplitude of a carrier signal.
Definition of signal for Students. 1  1 : a sign, event, or word that serves to start some action â¦ the manager gave the signal for the curtain to go down, and the audience â¦ cheered. 2  2 : a sound, a movement of part of the body, or an object that gives warning or a command The police officer made a signal with his hand. a traffic signal.