Guide to Configuring a Fiber Optic Sensing System


Combustion Dynamics Monitoring Systems (CDMS)

Promotional Flyer for Davidson's Combustion Dynamics Monitoring System

CDMS System Specifications

CDMS Test Results

CDMS System Configuration

Modern dry low NOx (DLN) gas turbines such as the Siemens 501F/G are designed for low emissions and are prone to combustion instabilities.  Combustion instabilities are caused by changes in fuel quality (the Wobbe Index), ambient temperature and humidity, engine conditions, and load.  Failure to maintain stable combustion can cause non-compliance with permitted emission levels, severe damage to an engine, and force the operators to turndown power de-rating an engine.  These conditions result in significant hidden costs and hidden losses of revenue generating capability which can severely erode the profitability of a power plant.

Over 1,000,000 Hours of Time in Service

High-Fidelity, Stable, and Temperature-Tolerant

Many DLN engines use conventinal low temperature combustion dynamics instrumentation to warn the operators of combustion dynamic conditions which can damage an engine.  This systems consist sensors that are not stable at elevated temperatures and deteriorate over time and lose sensitivity due to the heat.  When acoustic waveguides are used to position the transducers and sensors away from the heat, those waveguides attenuate the signals causing losses of low frequency and high frequency dynamics signals and fail to report the full extent of combustion dynamic activity.  Conventional instrumentation is also prone to generating false positive alarm conditions due to condensation in the waveguides, vibration, thermal transients, and grounding issues.  These false signals can cause operators or automated tuning systems to turn down power even though the actual combustion process is stable and well controlled. 


Davidson has developed an innovative, fiber-optic-based, temperature-tolerant combustion dynamics monitoring system for use in DLN gas turbines that provides high fidelity from DC to 10,000 Hz.  Extensive testing of our systems performed in collaboration with our customers in the lab and in the field has proven that our patented, direct-measurement systems provide better accuracy, fidelity, and stability over time than conventional electronic transducers.  In addition, our systems have built in health diagnostics which provide fail-safe operation eliminating the false positive alarm conditions.  Davidson’s breakthrough temperature-tolerant instrumentation provides unprecedented combustion dynamics monitoring reliability which is the first step and key to the development of effective automated combustion controls for low emission gas turbines.

We have installed our systems on GE and Siemens engines in Alabama, Arizona, Florida, Maryland, Pennsylvania, South Carolina, and Texas.  Join our growing list of satisfied customers around the country who are deriving the benefit of this revolutionary new system.  No engine modifications are required to install the system and a two man crew can complete the installation in three days during almost any outage.




Davidson offers a line of combustion dynamics monitoring systems customized for Siemens 501 and General Electric E and F series gas turbines. These turnkey systems include all of the transducers, cabling, and signal conditioning needed for a fully integrated combustion dynamics monitoring system

Data Sheets for Combustion Dynamics Monitoring System

CDMS System for use in General Electric Frame 7 and 9 gas turbines

CDMS GE Frame 7 Transducer

CDMS GE Frame 9 Transducer

CDMS System for use in Siemens 501 series of gas turbines

CDMS Siemens 501 Transducer