RdF Engineers have a long history of producing foil products (heaters, sensors & networks) to exacting specifications. Many of our products are qualified under a variety of military and aerospace programs. We specialize in finding economical solutions for limited production runs.

Define your application within the basics given in this guide and send them to us for a quick and economical solution.



RdF has produced foil sensors for many surface temperature measurements. The materials used for these measurements are as follows:

Nickel is a very high resistivity material with a useful temperature measuring range from 0°C to 260°C (32°F to 500°F). It has a nominal temperature coefficient of 0.0050 Ω/Ω/°C.

Copper is a low resistivity material with a useful temperature measuring range from -200°C to 150°C (-320°F to 300°F). It is very linear because its temperature coefficient
of 0.0029 Ω/Ω/°C remains constant throughout its operating range.

Balco® is a nickel-iron alloy generally used for low cost resistance sensors. It has a nominal temperature coefficient ranging from 0.0048 to 0.0053 Ω/Ω/°C. Balco® is a
trade name of AMEX Wire Corp. Driver-Harris also makes this material under the trade name Hytemco®.




Custom Foil Heaters
Foil heaters can be fabricated to any shape and can be designed to vary the watt density so that the heat is delivered to precise locations. Foil heaters generally use low temperature coefficient foils. However, higher temperature coefficient materials can be used to provide self regulation. Heaters can be designed to be non-magnetic and/or non-inductive.

Foil heaters provide more uniform heat distribution due to their low profile and intimate contact with the surface. This also contributes to faster heating and more reliable heater performance.



Teflon® and Kapton® are registered trademarks of Dupont


Bridge Completion Networks
When a full bridge-strain gage circuit is not used, RdF’s bridge completion devices can be incorporated to complete the measuring circuit. They are available for use with quarter bridge (single active) and half bridge (two active) strain gage configurations and 2 or 3 wire configurations.

Foil Compensation Devices
RdF manufactures foil compensation devices for load cell applications. The selection of materials allows for temperature compensation, bridge balancing, gage sensitivity, Young’s modulus compensation, as well as custom resistor compensation. These devices are designed to fit in small, non-stressed areas of the cell and contain all the components necessary in one flat flexible device.

Other Foil Products
Foil thermocouples Catalog No. T-F, Heat Flux Sensors Catalog HFS-A, HFS-C, and Custom Foil Heaters Catalog No. F-HTR.



For detailed information of the products listed, variations, custom designs, or application assistance, contact RdF.


Operating Temperature Range
–73°C to 177°C (–100°F to 350°F) nominal.
–200°C to 260°C (–320°F to 500°F) on request.

Kapton® (polyimide film) sealed with
acrylic adhesive for nominal temperature range,
polyimide sealed for extended range.

Lead Wires
#24 AWG stranded Teflon® insulated (standard)
polyimide insulated, ribbon leads or solder pads
available on request.


Insulation Resistance
50 MegW minimum at 50 VDC
at room temperature.

Maximum Power Density
40 W/in2 using materials described above.
See Data Sheet F-HTR for higher values.