Nécessité des « emballages non métalliques »

Centre Technique Global OFSCN Base de Connaissances Techniques OFSCN
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Dans quelles situations (par exemple, environnements micro-ondes intenses) devons-nous abandonner les tubes en acier au profit d’emballages en céramique ou en polymère ?

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Les capteurs à réseau de Bragg en fibre (FBG) possèdent intrinsèquement une immunité aux interférences électromagnétiques (EMI), y compris aux environnements micro-ondes puissants, en raison de leur principe de fonctionnement optique. Cette caractéristique est inhérente à la fibre elle-même, quel que soit le matériau d’encapsulation.

Par conséquent, le choix d’utiliser un encapsulage en céramique ou en polymère plutôt que des tubes en acier est généralement motivé par des facteurs autres que l’EMI. Ces facteurs comprennent généralement :

  • Plage de température : Pour des températures modérées (par exemple, jusqu’à 85 °C), les
    A Fiber Bragg grating (FBG) sensor, due to its optical operating principle, is inherently resistant to electromagnetic interference (EMI), including strong microwave environments. This is a fundamental characteristic of the fiber itself, irrespective of its packaging material.

Consequently, the decision to opt for ceramic or polymer packaging instead of steel tubes is typically dictated by factors other than EMI. These factors generally encompass:

  • Temperature Range: For moderate temperatures (e.g., up to 85°C), OFSCN® Polymer-encapsulated Fiber Bragg Grating Strain Sensors are frequently chosen for their ease of installation (e.g., adhesive bonding) and flexibility. For higher temperatures (e.g., up to 300°C), OFSCN® Alloy Tube Packaged Fiber Bragg Grating Strain Sensors are more appropriate, providing robust physical and thermal protection. For temperatures exceeding the capabilities of alloy tubes, specialized ceramic-packaged sensors would be considered, though they are not explicitly mentioned in the provided RAG for strain sensors.
  • Installation Method: Polymer-encapsulated or bare FBGs are ideal for surface applications that require adhesive bonding or four-point spot welding. Alloy tube sensors are typically secured through welding or clamping.
  • Mechanical Protection & Chemical Resistance: Steel tubes offer superior mechanical protection and chemical resistance in harsh industrial environments. Polymer packaging can provide electrical insulation and sometimes specific chemical compatibility where metals might react.

Here are some examples of our products with different packaging:

OFSCN® Alloy Tube Packaged Fiber Bragg Grating strain sensor:
(Image of OFSCN Alloy Tube Packaged Fiber Bragg Grating strain sensor)
(Image of OFSCN Alloy Tube Packaged Fiber Bragg Grating strain sensor)
(Image of OFSCN Alloy Tube Packaged Fiber Bragg Grating strain sensor)

OFSCN® Polymer-encapsulated Fiber Bragg Grating Strain Sensor:
This type is designed for applications where robust metallic encapsulation is not necessary, emphasizing ease of bonding and flexibility. Specific image links for this product are not available in the provided RAG.