{"title":"Magnetic Strain Sensors, Mounted Without Glue","description":"\u003cp\u003e\u003cstrong\u003eMagnetic strain sensors\u003c\/strong\u003e hold on ferromagnetic components by themselves and press a foil strain gauge so firmly against the surface that friction takes over the job of the adhesive. They read the surface strain with the same quality as a bonded gauge – after seconds instead of three quarters of an hour, and without drilling, grinding or gluing.\u003c\/p\u003e\n\u003ch2\u003eWhen a magnet sensor is worth it\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eThe component is left as it is.\u003c\/strong\u003e No adhesive, no screws, no drilling.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eReusable.\u003c\/strong\u003e The sensor comes off as easily as it went on and is set at the next measuring point.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCannot be overloaded.\u003c\/strong\u003e Instead of damage, an offset occurs.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFor steel structures\u003c\/strong\u003e – for checking FEM calculations and for stress analysis.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eThe designs compared\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eStrain sensor DKFD\u003c\/strong\u003e – holds by its own magnet, steel housing Ø 34 mm, protection IP54, range ± 300 … ± 500 µε depending on the surface. Reads through coats of paint.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eMagnetic holder DKFA\u003c\/strong\u003e – two springs and two knurled screws press a StrainPad (Ø 10 mm, 0.2 mm high) on with 100 … 300 N, maximum strain ± 800 µm\/m.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhat you need with them\u003c\/h3\u003e\n\u003cp\u003eBoth sensors are \u003cstrong\u003epassive\u003c\/strong\u003e and work with 350 Ω foil strain gauges and gauge factor 2.0 – so on any strain gauge amplifier. Suitable units are listed under \u003ca href=\"\/en\/collections\/dms-brueckenmessverstaerker-ein-kanal\"\u003estrain gauge bridge amplifiers\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eFor round tie bars there are the \u003ca href=\"\/en\/collections\/dehnung-aufklemm-dk\"\u003eclamp-on strain sensors\u003c\/a\u003e, for fixed measuring points the \u003ca href=\"\/en\/collections\/dehnung-aufschraub-ds\"\u003ebolt-on strain transducer\u003c\/a\u003e. \u003ca href=\"\/en\/collections\/dehnungsmessung\"\u003eStrain measurement \u0026amp; strain gauges\u003c\/a\u003e gives an overview.\u003c\/p\u003e","products":[{"product_id":"dkfa-alternative-dehnungsmessstreifen-dms-magnethalter","title":"DKFA alternative to bonded strain gauges – magnetic holder","description":"\u003cp\u003eSurface strain measured without glue: two springs and two knurled screws press the \u003cstrong\u003eStrainPad\u003c\/strong\u003e – an encapsulated foil strain gauge of 10 mm diameter and 0.2 mm height – so firmly against a ferromagnetic surface that friction takes over the task of the adhesive.\u003c\/p\u003e\n\u003cp\u003eWhat the gauge then reads is the surface strain, in the same quality as a bonded gauge, and it reads it within seconds instead of the three quarters of an hour a bonded gauge needs to be prepared, glued and cured. The holder is taken off as quickly as it went on and used again on the next measuring point; nothing is drilled, nothing is ground, nothing is consumed. It cannot be overloaded – instead of damage an offset appears.\u003c\/p\u003e\n\u003ch2\u003eMeasurement\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDirect reading of the surface strain, like a bonded strain gauge\u003c\/li\u003e\n\u003cli\u003eMaximum strain ± 800 µm\/m\u003c\/li\u003e\n\u003cli\u003e350 Ω foil gauge, k = 2.0 ± 3 %\u003c\/li\u003e\n\u003cli\u003eUniaxial, 0.6 mm constantan grid, polyimide encapsulation, Ø 10 mm at 0.2 mm height\u003c\/li\u003e\n\u003cli\u003eAccuracy \u0026lt; ± 0.5 % of full scale, transverse sensitivity −0.1 %\u003c\/li\u003e\n\u003cli\u003eCannot be overloaded – an offset appears instead of damage\u003c\/li\u003e\n\u003cli\u003e1,000,000 load cycles at 300 µm\/m strain\u003c\/li\u003e\n\u003cli\u003ePassive – no amplifier inside; recommended bridge voltage 1 V, 10 V at most\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eMounting and use\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eHolds magnetically – no drilling, grinding or gluing\u003c\/li\u003e\n\u003cli\u003eMounted and removed in seconds, reusable\u003c\/li\u003e\n\u003cli\u003eContact force 100 … 300 N, settling time 15 minutes\u003c\/li\u003e\n\u003cli\u003eSmallest radius of curvature 3 mm\u003c\/li\u003e\n\u003cli\u003eOperating temperature 5 … 60 °C, reference temperature 23 °C\u003c\/li\u003e\n\u003cli\u003eTemperature matching of 10.8·10⁻⁶ 1\/K for ferritic steel is possible\u003c\/li\u003e\n\u003cli\u003eHolders made of aluminum\u003c\/li\u003e\n\u003cli\u003eFor dynamic applications, for checking FEM calculations and for stress analysis\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eVersions\u003c\/h2\u003e\n\u003cp\u003eShown is the magnet holder with StrainPad. Other standard holders are available and individual ones are built to the application. Tell us the measuring point and we will name the holder that fits.\u003c\/p\u003e","brand":"octogon GmbH","offers":[{"title":"Default Title","offer_id":57266202935622,"sku":"DKFA","price":1960.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/5558\/6374\/files\/DKFA_DGA_produkt.webp?v=1790528259"},{"product_id":"dkfd-alternative-dehnungsmessstreifen-dms-dehnungssensor","title":"DKFD alternative to bonded strain gauges – strain sensor","description":"\u003cp\u003eSurface strain measured where it arises, without glue: the \u003cstrong\u003estrain sensor\u003c\/strong\u003e DKFD is the \u003cstrong\u003ealternative\u003c\/strong\u003e 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.\u003c\/p\u003e\n\u003cp\u003eMounting 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.\u003c\/p\u003e\n\u003ch2\u003eMeasurement\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDirect reading of the surface strain, like a bonded strain gauge\u003c\/li\u003e\n\u003cli\u003eMeasuring range ± 300 … ± 500 µε, depending on the surface\u003c\/li\u003e\n\u003cli\u003eFoil strain gauge with GF = 2.0, bridge resistance 350 Ω\u003c\/li\u003e\n\u003cli\u003eOne quarter bridge active, 350 Ω completion resistor in the connector\u003c\/li\u003e\n\u003cli\u003eAccuracy and linearity each \u0026lt; ± 0.5 % of RO\u003c\/li\u003e\n\u003cli\u003eSensitivity tolerance ± 0.2 %, transverse sensitivity 0.9 ± 0.2 %\u003c\/li\u003e\n\u003cli\u003eCalibrated to GF = 2.00 for dynamic applications\u003c\/li\u003e\n\u003cli\u003ePassive – external amplifier recommended, such as MBA100, VDA or Monitor DU-1D\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eMounting and use\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMounted and removed in seconds with the tool included\u003c\/li\u003e\n\u003cli\u003eHolds on magnetic structures – no adhesive, no screws, no drilling\u003c\/li\u003e\n\u003cli\u003eThe surface needs neither cleaning nor grinding, and the reading passes through coats of paint\u003c\/li\u003e\n\u003cli\u003eSensors are interchangeable without recalibrating the amplifier\u003c\/li\u003e\n\u003cli\u003eReusable – no single-use material, no consumables\u003c\/li\u003e\n\u003cli\u003eSteel housing Ø 34 mm, 36 mm high, protection IP54\u003c\/li\u003e\n\u003cli\u003eSupply 5 V DC, 8 V DC at most, current draw below 15 mA\u003c\/li\u003e\n\u003cli\u003eOperating temperature 0 … +50 °C, storage 0 … +70 °C\u003c\/li\u003e\n\u003cli\u003eWeight including cable 200 g\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eCable lengths\u003c\/h2\u003e\n\u003cp\u003e3 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.\u003c\/p\u003e\n\u003cp\u003eSupplied 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.\u003c\/p\u003e","brand":"octogon GmbH","offers":[{"title":"Default Title","offer_id":57427213517126,"sku":"DKFD","price":0.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/5558\/6374\/files\/DKFD_DTS_produkt.webp?v=1790528258"}],"url":"https:\/\/octogon.org\/en\/collections\/strain-magnetic-dm.oembed","provider":"octogon GmbH","version":"1.0","type":"link"}