DKFD alternative to bonded strain gauges – strain sensor

Surface strain measured where it arises, without glue: the strain sensor DKFD is the alternative to the bonded strain gauge. It holds itself on a ferromagnetic surface by its own magnet and presses the foil strain gauge, protected under a stainless steel foil, so firmly against the surface that friction takes over the task of the adhesive.

Mounting takes seconds instead of the three quarters of an hour a bonded gauge needs. The surface is neither cleaned nor ground, and coats of paint do not stop the reading. Calibrated to GF = 2.00, the sensor reads tension and compression directly and can be exchanged without recalibrating the amplifier. It cannot be overloaded – an offset appears instead of damage – and it is used again. The usual instrument for checking FEM calculations and for stress analysis on flat steel structures.

Measurement

• Direct reading of the surface strain, like a bonded strain gauge
• Measuring range ± 300 … ± 500 µε, depending on the surface
• Foil strain gauge with GF = 2.0, bridge resistance 350 Ω
• One quarter bridge active, 350 Ω completion resistor in the connector
• Accuracy and linearity each < ± 0.5 % of RO
• Sensitivity tolerance ± 0.2 %, transverse sensitivity 0.9 ± 0.2 %
• Calibrated to GF = 2.00 for dynamic applications
• Passive – external amplifier recommended, such as MBA100, VDA or Monitor DU-1D

Mounting and use

• Mounted and removed in seconds with the tool included
• Holds on magnetic structures – no adhesive, no screws, no drilling
• The surface needs neither cleaning nor grinding, and the reading passes through coats of paint
• Sensors are interchangeable without recalibrating the amplifier
• Reusable – no single-use material, no consumables
• Steel housing Ø 34 mm, 36 mm high, protection IP54
• Supply 5 V DC, 8 V DC at most, current draw below 15 mA
• Operating temperature 0 … +50 °C, storage 0 … +70 °C
• Weight including cable 200 g

Cable lengths

3 m as standard; 0.5 m, 5 m and 10 m are available, as is any intermediate length from 0.5 to 10 m. The connection is a six-pin connector, where 350 Ω can be measured across the bridge.

Supplied with the sensor, cable and connector and the mounting tool, Ø 16 mm and 125 mm long. CE and UKCA are declared, RoHS for the whole range.