Signal Conditioning Introduction


Signal conditioning is a vital part of the data acquisition process and measurement chain. Poor choice of signal conditioning can seriously compromise the overall quality of the measurements taken by any data acquisition system and as a result the choice of conditioning equipment is important when specifying a measurement solution.

After consideration of the signal quality of a conditioning system, the functionality and integration aspects of the equipment should be seriously considered. Traditionally conditioning equipment has remained separated from the data acquisition systems using solely analogue links between the two. This has some advantages, particularly in allowing multiple vendor choices, but does also miss some opportunities for improving the entire measurement chain. For instance with modern internal or digitally connected external programmable conditioning systems on-the-fly changes in parameters can be handled and integrated into the acquired data (such as gain changes). Automation of calibration, and overload / short circuit monitoring is also possible and provides useful aids to the over-pressed measurement engineers of today.

HGL Dynamics has always taken a lot of care to ensure that its high-quality data acquisition systems are matched with equally high-quality signal conditioning systems and now provides internal and external conditioning solutions for all of its data acquisition products. HGL can also supply a range of external conditioning systems for 3rd party acquisition systems as required.

The following sections provide some overview information on the internal and external solutions available for our data acquisition systems to aid in product selection.


Internal Conditioning Solutions

HGL provides a number of internal conditioning options for its range of data acquisition devices, the following provides an overview of the options based on the HGL acquisition system families in which they can be utilised.

Fylde Dragonfly Range

dragonfly machined front



The low-power and cost conscious highly modular Dragonfly platform provides a basis for a wide range of individual low cost per channel conditioning modules, some of which can be stacked together to provide near universal conditioning within the compact Dragonfly chassis.

The Dragonfly conditioning modules provide a simple set of fully programmable functions (gain, coupling etc) specific to each module type. All modules also allow direct voltage inputs to be taken (bypassing the conditioning). Currently the module set includes:

  • IEPE module - 1x, 10x, 100x gain, AC coupled, CI generator (4 & 8 mA settings).
  • Bridge module - 1x, 10x, 100x, 1000x gain, DC coupled, CV generator (5V, 10V, 15V settings), shunt cal resistor, auto-zero function. 1/4, 1/2 and full completion options (120Ω, 350Ω, 1000Ω).
  • Dynamic Strain module - 1x, 10x, 100x, 1000x gain, AC coupled, CI generator (5mA, 10mA, 20mA).
  • Fixed Bridge module - 1000x fixed gain, 350Ω fixed completion, 1/4, 1/2, full bridge, auto zero function.
  • Thermocouple module - 1x, 10x, 100x gain, individual cold junction compensation per channel, most common thermocouple types supported.
  • More coming soon....


(Modular Conditioning System)




A modular low-cost conditioning option for the HGL Eagle and HDR range of data acquisition systems.The MCS provides a full length motherboard onto which individual 8-channel modular conditioning cards can be mounted. Different modules can be mounted on any one of the 4 standard positions (32 channels).

The MCS motherboard also provides a monitor out function (usually suitable for attaching to an oscilloscope etc) and a headphone output.

All MCS functions are fully programmable, but the range of functionality is limited to reduce costs. The MCS range currently includes the following daughter cards:

  • IEPE & Voltage - 8 channels, 1x, 10x, 100x, 1000x gain, AC/DC coupling
  • IEPE, Voltage & Proximity Probe - - 8 channels, 1x, 10x, 100x, 1000x gain, AC/DC coupling
  • Dynamic Strain (2 wire) & Voltage - 1x, 10x, 100x, 1000x gain, AC/DC coupling, Constant Current (CI) generator
  • more coming soon...
Entegra Universal Range




The compact dimensions of the Hummingbird series of data acquisition systems presents its own challenges as regards signal conditioning. Additionally the requirement to provide conditioning that does not adversely affect the performance of the Hummingbird acquisition card (135dB SNR) whilst providing universal conditioning has led to the development of a world class ultra-miniature conditioning card.

The modules are all fully programmable and include a rich set of features allowing use for virtually any application.

The modules described here are designed for Hummingbird, but can be fitted to the Eagle range as well. Currently two modules are provided each of which supports 8 analogue input channels:

  • Universal - Voltage, IEPE, Bridge (strain and Kulite), and Dynamic Strain. The module provides 1x, 10x, and 100x gain, AC/DC coupling, shunt cal resistor (for bridge), auto zero (for bridge), constant current (CI) and voltage (CV) generators.
  • Proximity Probe - Voltage, IEPE and Proximity Probe conditioning. The module provides 1x, 10x, and 100x gain, AC/DC coupling, CI (for IEPE) and level shifting (for Proximity Probes).
  • More modules are planned...


External Conditioning Systems

HGL has a long-standing partnership with Fylde Electronics based in Preston, UK. Fylde Electronics has specialised for many years in providing high quality signal conditioning systems for a wide range of industries including aerospace, marine, and industrial. Fylde has a wide range of solutions for signal conditioning, tip clearance and other applications and although only three ranges are presented on these pages HGL can provide any of the Fylde range of equipment. For specialised requirements both HGL and Fylde are interested in providing customised solutions.

For reasons of simplicity only three ranges are presented on these pages:


μAnalog2 uanalogue   A low cost multi-channel solution which addresses all signal conditioning requirements using a range of plug-in modules and enclosures. Fit any combination of signal conditioning modules for application with the chosen sensor type. Screw on the rear panel adaptor if one is needed for your sensor. Add the USB data acquisition module to connect directly to your PC or use the BNC and other adaptors to connect to your HGL or other data acquisition equipment. μAnalog2 is not programmable via software but users can set various parameters (board dependent) through the application of on-board jumpers.
  1. Panelled 

(Series 5)

all-racks   The 5 Series carries on the Fylde tradition for high quality analogue instrumentation, addressing a need for easy-to-use, rugged and versatile instruments with benchmark performance standards. The series features front panel control using a simple push button and LED panel, with RS232 serial control available as an option. A wide range of case styles and modularity enables the user to specify as few or as many channels as required without the overheads of a sparsely populated multi-channel enclosure. Modules may be mixed within enclosures as required on a per channel basis. The 5 Series is an analogue in, analogue out system, so most types of data acquisition (including all HGL products) can be connected bia the industry standard BNC output connectors. Customer choice connectors are also available to special order.
Programmable fe859ta1   The programmable range provides the highest level of integration between the instrumentation and the data acquisition system. In the case of HGL Data Acquisition systems the operation of the Fylde equipment is completely transparent within the overall measurement solution. All Fylde settings can be configured pre-acquisition and changed during acquisition with all parameters recorded with the acquired data for use in later processing. The Programmable range are controlled only by a computer through either RS232 or Ethernet. Integration of test software such as National Instruments LabView, Keithley's TestPoint, or HP's Vee with Fylde's programmable signal conditioning equipment is simple because the commands to control the instrument conform to the IEEE 488.2 standard. In addition Fylde provide software drivers for National Instruments' LabView.

For all other requests or requirements please feel free to contact

  • Dr Jim Hone (This email address is being protected from spambots. You need JavaScript enabled to view it. ) or
  • Steve O'Donnell (This email address is being protected from spambots. You need JavaScript enabled to view it. )

with your requirements or questions.