Description
Application Scenarios
In a combined-cycle power plant, a gas turbine’s exhaust temperature spread monitoring system depends on accurate, real-time thermal data to detect combustion anomalies and prevent catastrophic failures. The WOODWARD 9905-970 functions as the dedicated input node in this safety-critical loop, converting signals from six 100Ω RTD sensors positioned across the exhaust plenum into precise temperature readings for the main controller. When a partial blockage in a fuel nozzle began causing localized hot spots, the 9905-970 detected the subtle temperature differential that triggered an alarm, allowing operators to adjust fuel distribution before any turbine damage occurred.
Parameter
| Parameter | Value/Description |
|---|---|
| Product Model | WOODWARD 9905-970 |
| Manufacturer | Woodward |
| Product Category | LinkNet 6-Channel Analog Input Module |
| Input Channels | 6 independent analog channels |
| RTD Compatibility | 100Ω RTD sensors |
| Input Voltage | 24 VDC |
| Input Impedance | 33K Ohms ±5% |
| Operating Temperature | -40°C to +85°C |
| Transient Protection | 900 VDC |
| Display | 24-character LED status indicators |
| Communication Protocol | LinkNet (shielded twisted pair) |
| Dimensions | 14 × 11 × 4 inches (approx.) |
| Weight | 2 lbs (approx. 0.9 kg) |
Technical Principles and Innovative Values
- Innovation Point 1 – Dedicated RTD Signal Conditioning: The WOODWARD 9905-970 is purpose-engineered for 100Ω RTD input, not a generic analog card repurposed for temperature measurement. Its input circuitry is optimized to handle the low-level resistance changes from RTD sensors with high stability, providing signal accuracy that general-purpose modules cannot match in high-vibration turbine environments.
- Innovation Point 2 – Distributed Architecture via LinkNet: Unlike centralized I/O systems that require long signal runs back to a main cabinet, the 9905-970 operates as a remote node in the LinkNet network. This distributed approach places the analog-to-digital conversion closer to the sensor, minimizing noise pickup and reducing wiring complexity across large turbine installations.
- Innovation Point 3 – Robust Transient Protection: The WOODWARD 9905-970 incorporates 900 VDC transient protection on its power supply input, safeguarding the module against the electrical surges commonly encountered in industrial power generation environments where switching transients and ground faults are operational realities.
