{"id":7640,"date":"2026-07-16T18:45:58","date_gmt":"2026-07-17T02:45:58","guid":{"rendered":"https:\/\/szlmi.com\/?p=7640"},"modified":"2026-07-16T18:55:04","modified_gmt":"2026-07-17T02:55:04","slug":"construction-machinery-safe-load-indicators-sli-how-they-work-where-theyre-used-and-what-to-look-for-when-buying","status":"publish","type":"post","link":"https:\/\/szlmi.com\/fr\/construction-machinery-safe-load-indicators-sli-how-they-work-where-theyre-used-and-what-to-look-for-when-buying\/","title":{"rendered":"Indicateurs de charge admissible (SLI) pour engins de chantier : comment fonctionnent-ils, o\u00f9 sont-ils utilis\u00e9s et quels crit\u00e8res prendre en compte lors de l'achat ?"},"content":{"rendered":"

Auteur :<\/strong> Edited by the technical department of SeeZol, an industrial safety systems integrator with extensive practical experience in selecting SLI\/LMI equipment for forklifts, loaders, and excavators.<\/p>\n\n\n\n

Publication Date:<\/strong> July 17, 2026 \u00b7 Last Review Date:<\/strong> July 17, 2026<\/p>\n\n\n\n

Disclaimer:<\/strong> Any suggestions, specification thresholds, or rankings in this article remain vendor-neutral.<\/p>\n\n\n\n

En bref<\/h2>\n\n\n\n

A Indicateur de charge de s\u00e9curit\u00e9 (SLI)<\/a> is a real-time weight-monitoring safety device used on construction machinery \u2014 forklifts, loaders, excavators, and similar equipment \u2014 that compares the current load against the machine’s rated safe load and triggers staged alarms (and, on some models, automatic shutdown) as that threshold is approached or exceeded. It’s the simpler cousin of a Load Moment Indicator (LMI): an SLI monitors weight alone, while an LMI calculates weight \u00d7 working radius for equipment like cranes that need to track a variable working radius. When buying, the parameters that matter most are measurement accuracy (\u00b12\u20133% for industrial-grade), ingress protection (IP65 minimum outdoors), response time (\u2264200 ms), and staged alarm logic \u2014 not just the lowest price on the spec sheet.<\/p>\n\n\n\n

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Sommaire<\/h2>\n\n\n\n
    \n
  1. What an SLI Is \u2014 and How It Differs from an LMI<\/a><\/li>\n\n\n\n
  2. Core Components and Working Principle<\/a><\/li>\n\n\n\n
  3. Where SLI Is Actually Used<\/a><\/li>\n\n\n\n
  4. Buying Checklist: Core Parameters to Compare<\/a><\/li>\n\n\n\n
  5. Certifications and Standards to Ask a Vendor About<\/a><\/li>\n\n\n\n
  6. Installation and Maintenance<\/a><\/li>\n\n\n\n
  7. Field Notes: Common Failure Patterns<\/a><\/li>\n\n\n\n
  8. Erreurs courantes lors d'un achat<\/a><\/li>\n\n\n\n
  9. FAQ<\/a><\/li>\n\n\n\n
  10. \u00c0 propos de cet article<\/a><\/li>\n<\/ol>\n\n\n\n
    \n\n\n\n

    <\/a><\/p>\n\n\n\n

    1. What an SLI Is \u2014 and How It Differs from an LMI<\/h2>\n\n\n\n

    A Indicateur de charge de s\u00e9curit\u00e9 (SLI)<\/strong> is an industrial safety device that measures the actual weight on a machine’s load-bearing component in real time, compares it to that machine’s rated safe load, and issues a staged audible\/visual alarm \u2014 and on some models, an automatic shutdown signal \u2014 as the load approaches or exceeds that rating.<\/p>\n\n\n\n

    The distinction people mix up most often:<\/p>\n\n\n\n

    <\/th>SLI (Safe Load Indicator)<\/th>LMI (Load Moment Indicator)<\/th><\/tr><\/thead>
    Ce qu'il mesure<\/td>Load weight only<\/td>Load weight \u00d7 working radius (the full “moment”)<\/td><\/tr>
    Typical equipment<\/td>Forklifts, loaders, grab machines \u2014 fixed or single-axis load paths<\/td>Cranes and other equipment with a variable working radius<\/td><\/tr>
    Why the difference matters<\/td>A forklift’s safe capacity doesn’t change with reach in the same way a crane’s does, so weight alone is a sufficient safety signal<\/td>A crane can safely lift a heavy load at a short radius and unsafely lift the same load at a long one \u2014 weight alone isn’t enough<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    They are not interchangeable, and buying the wrong category for your equipment (an SLI on a crane doing variable-radius lifts, for instance) leaves a real monitoring gap.<\/p>\n\n\n\n

    It’s worth noting that even a fixed-path machine like a forklift doesn’t have a single flat weight limit \u2014 regulators define rated capacity relative to a specific “load center” (the horizontal distance from the fork face to the load’s center of gravity), because a load carried further out on the forks effectively creates more tipping moment than the same weight carried close in. An SLI that only checks raw weight against one number, without accounting for load position, is a simplification \u2014 a genuinely well-specified system accounts for this the way the underlying safety standards do (see Section 5).<\/p>\n\n\n\n

    <\/a><\/p>\n\n\n\n

    2. Core Components and Working Principle<\/h2>\n\n\n\n

    A complete SLI system has four coordinated parts:<\/p>\n\n\n\n