Digital guide
You are here:
Woodward 8904-238
Product Name: Linear Position Sensor (Woodward part 8904-238), cross-referenced to Macro Sensors VRT-750-8000-0585 DC-operated LVDT.
Overview: A sealed, DC-powered linear variable differential transformer (LVDT) used for high-accuracy position feedback in Woodward turbine, compressor, and fuel-control actuators. It carries the robustness of the Macro Sensors VRT-750 series with an 8000-thou (8.0 in / 203.2 mm) measurement range.
Detailed content
Technical Specifications:
-
Series: VRT-750 (3/4 in / 19 mm diameter body)
-
Supplied Woodward number: 8904-238
-
Equivalent Macro Sensors model: VRT-750-8000-0585
-
Measurement range: ±4.0 in (±101.6 mm) full stroke class, 8.0 in overall travel
-
Output: pre-calibrated DC voltage (typical 0–±10 V DC class, per VRT-750 family)
-
Excitation: DC input with integrated electronics (DC-DC LVDT)
-
Linearity: ≤ ±0.25 % of full scale (best straight line)
-
Repeatability: < 0.01 % FSO; Hysteresis: < 0.01 % FSO
-
Operating temperature: 0 °F to +160 °F (−20 °C to +70 °C)
-
Vibration tolerance: 20 g to 2 kHz; Shock survival: 100 g, 11 ms
-
Ingress protection: IEC IP-68 sealed construction
Material & Structure: All-stainless-steel body with hermetically sealed coil windings; axial or radial sealed connector; ruggedized for industrial and turbomachinery environments.
Working Principle: The core displacement changes the inductive coupling between primary and secondary coils; built-in electronics convert the AC LVDT signal into a pre-calibrated DC output proportional to position, requiring no external signal conditioner.
Application Scenarios: Valve-stem position feedback, actuator stroke measurement, compressor guide-vane position, SPC/servo-position loops in Woodward steam and gas turbine fuel systems.
Installation Requirements: Mount with the threaded body or supplied hardware; align the core freely without side loading; use the matched sealed connector; independent of external LVDT signal conditioners.
Usage Notes: Avoid sideways mechanical loads on the core; keep within the −20 °C to +70 °C range; verify sealing integrity in high-pressure washdown or submerged duty.
