Fisher 546 Series Electro-Pneumatic Transducers
Meeting customary seismic qualifications for nuclear service, Models 546, 546S and 546NS intercept a direct-current input signal and utilize a torque motor, nozzle-flapper and pneumatic relay to translate the signal to a proportional pneumatic output signal. At the same time, the nozzle pressure that drives the relay is piped to the torque motor feedback bellows, which allows for a comparison between input signal and nozzle pressure and the correction of inconsistencies in nozzle pressure.
Integrated pneumatic relay for the Fisher™ 546 Series is mounted on the exterior of the case. It is capable of being taken off without interrupting electrical or pressure connections or compromising explosion safety. These transducers feature convenient-access screw driver adjustments for span and zero, complete with arrows signifying rotation to escalate settings.
For the 546 Series, action can be reversed without the need for additional parts. Thanks to the elevated natural frequency of torque motor moving parts, trivial vibration influence is seen with these transducers.