Reciprocity calibration methods have been well established for acoustic transducers and hydrophones.
Hill and Adams [3, 17] analyzed generalized cases of reciprocity calibration, in which [T.sub.i] and R of transducers differ and the law of reciprocity is no longer satisfied.
Reciprocity calibration cannot provide the ratio of Ti and R of the reference transducer, required in equation (3) or (3a) expressing the receiving sensitivity, [R.sub.2].
Key words: acoustic measurements; acoustical calibration; calibration of microphones; electroacoustics; laboratory standard microphone; measuring microphone; microphone calibration; microphone pressure calibration; microphone reciprocity calibration; pressure reciprocity calibration of microphones; reciprocity calibration; standard microphones.
A block diagram of the microphone pressure reciprocity calibration system is shown in Fig.
The reciprocity calibration procedure implemented at NIST is a primary method used to determine the sensitivities of three microphones in a triad comprising two NIST-owned microphones (microphones 1 and 2) and the customer microphone (microphone 3).
The basic principle of the reciprocity calibration method is that three transducers, all of which are uncalibrated, are used as emitter and receiver successively.
1, reciprocity calibration process consists of three steps.
NDIS 2109  outlines reciprocity calibration. Reciprocity calibration works on reciprocity theorem that is known from electrical circuits.
The primary advantage of the reciprocity calibration technique is that it avoids the necessity of measuring or producing a known mechanical displacement or force.
Marcotte: "The Reciprocity Calibration
of Piezoelectric Accelerometers", Journal of Acoustical Society of America, 24, (4), July 1952.