pistonphone การใช้

• Dosimeter manufacturers recommend that the instrument be calibrated with an acoustical calibrator such as a pistonphone before and after each measurement to verify reliable operation.
• AC electrical current could produce pressure variations in the " thermaphone . " Certain types of microphones were thus calibrated with the pistonphone and used as lab standards.
• :See Microphone in the section " Measurement microphones . " 2oth century methods included the pistonphone, which mechanically moved a piston a known distance in a known space to create known pressure variations up to 250 Hz.
• Since their output is also dependent on the volume of the chamber ( coupling volume ), differences in shape and load volume between different models of microphone will have an influence on the resulting SPL, requiring the pistonphone to be calibrated accordingly.