The Fairchild TD7800-421 is an electro-pneumatic transducer from the Model T7800 series, designed to convert electrical current signals into proportional pneumatic pressure. Here's a detailed overview:

Specifications

• Input Signal: 4–20 mA
• Output Pressure: 20–100 kPa (3–15 psig)
• Supply Pressure: Up to 150 psig
• Flow Capacity: 11 SCFM (18.7 m³/hr) at 150 psig supply
• Accuracy: ±0.25% of full scale
• Pressure Connections: 1/4" FNPT
• Electrical Connection: DIN 43650 plug
• Body Material: Aluminum
• Diaphragm: Nitrile or Dacron
• Mounting: Panel or manifold mount