Fisher® 546
Fisher® 546 transducers receives a direct-current input signal and use a torque motor, nozzle-flapper, and pneumatic relay to convert the signal to a proportional pneumatic output signal. Nozzle pressure, which operates the relay, is also piped to the torque motor feedback bellows. This provides a comparison between input signal and nozzle pressure and corrects errors in nozzle pressure.
Specification
Fisher 546 Electro Pneumatic Transducer
Available Configurations:
Electro-pneumatic signal transducer with explosion-proof case and coverThe 546 can be ordered with or without a Fisher 67filter regulator. A 51 mm (2 inch) circular supply pressure gauge may be mounted on the regulator.
Input Signals
4 to 20 mA DC
10 to 50 mA DC,
1 to 9 VDC,or
two-way split range using any half of one of the standard input signal spans
Internal Resistance of Torque Motor
4 to 20 mA DC Input Signal: 176 ±10 ohms
10 to 50 mA DC Input Signal: 90 ±10 ohms
1 to 9 VDC Input Signal: 1300 ±50 ohms
(temperature-compensated circuit)
Output Signals
Ranges:
0.2 to 1.0 bar (3 to 15 psig), 0.4 to 2.0 bar (6 to 30psig), 0 to 1.2 bar (0 to 18 psig), or 0 to 2.3 bar (0 to 33 psig)
Action:
The 546 is field-reversible between direct and reverse action.
Supply Pressure(1)
Recommended:
0.3 bar (5 psig) higher than upper range limit of output signal.
Maximum:
3.5 bar (50 psig)
Maximum Steady-State Air Consumption(2)
At 1.4 bar (20 psig) Supply Pressure:
0.6 normal m3/hr (21 scfh)
At 2.4 bar (35 psig) Supply Pressure:
0.8 normal m3/hr (30 scfh)
Maximum Output Air Capacity(2)
At 1.4 bar (20 psig) Supply Pressure:
12.9 normal m3/hr (480 scfh)
At 2.4 bar (35 psig) Supply Pressure:
18.5 normal m3/hr (690 scfh)
Performance(3)
Reference Accuracy:
±0.75% of output signal span
Independent Linearity:
±0.50% of output signal span
Open Loop Gain:
26
Frequency Response:
Gain is attenuated 3 dB at 20 Hz with transducer output signal piped to a typical instrument bellows with 305 mm (12 inches) of 1/4inch tubing<
Electromagnetic Interference (EMI):
Tested per IEC 61326-1 (Edition 1.1). Meets emission levels for Class A equipment (industrial locations) and Class Be quipment (domestic locations). Meets immunity requirements for industrial locations
Electrical Classification
Hazardous Area:
CSA— Explosion-proof, Dust Ignition-proof, Div 2
FM— Explosion-proof, Non-incendive
NEMA 3R, CSA enclosure 3
NEMA 3R mounting orientation requires vent location to be below horizontal.
Adjustments
Zero and Span Adjustments:
Screwdriver adjustments located inside case
Connections
Supply Pressure:
1/4 NPT internal located on side of case, (or located on the 67CFR filter-regulator if mounted)
Output Pressure:
1/4 NPT internal located on side of case
Vent:
1/4 NPT internal with screen located on relay
Electrical:
1/2 NPT internal located on bottom of case<
Approximate Weight
4.1 kg (9 pounds)
Resources
Technical Data-Sheet
Fisher 546 Electro Pneumatic TransducerFisher_546_Electro_Pneumatic_Transducer.pdf
Technical Data-Sheet
Fisher 546 Electro Pneumatic TransducerFisher_546_Electro_Pneumatic_Transducer.pdf