{"id":203,"date":"2018-12-20T08:25:00","date_gmt":"2018-12-20T08:25:00","guid":{"rendered":"http:\/\/tis-eg.com\/en\/?p=203"},"modified":"2018-12-20T08:25:37","modified_gmt":"2018-12-20T08:25:37","slug":"what-is-load-cell","status":"publish","type":"post","link":"https:\/\/tis-eg.com\/en\/what-is-load-cell\/","title":{"rendered":"what is load cell ??"},"content":{"rendered":"

A\u00a0load cell<\/b>\u00a0is a\u00a0transducer<\/a>\u00a0that is used to create an\u00a0electrical signal<\/a>\u00a0whose magnitude is directly proportional to the\u00a0force<\/a>\u00a0being measured. The various load cell types include hydraulic, pneumatic, and strain gauge.<\/p>\n

rain gauge load cell.<\/span><\/h2>\n
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Push-pull rod load cell spring element<\/p>\n<\/div>\n<\/div>\n<\/div>\n

Strain gauge load cells are the most common in industry. These load cells are particularly stiff, have very good resonance values, and tend to have long life cycles in application. Strain gauge load cells work on the principle that the\u00a0strain gauge<\/a>\u00a0(a planar resistor) deforms when the material of the load cells deforms appropriately. Deformation of the strain gauge changes its electrical resistance, by an amount that is proportional to the strain. The change in resistance of the strain gauge provides an electrical value change that is calibrated to the load placed on the load cell.<\/p>\n

A load cell usually consists of four strain gauges in a\u00a0Wheatstone bridge<\/a>\u00a0configuration. Load cells of one strain gauge (quarter bridge) or two strain gauges (half bridge) are also available.<\/sup>The electrical signal output is typically in the order of a few millivolts (mV) and requires amplification by an\u00a0instrumentation amplifier<\/a>\u00a0before it can be used. The output of the transducer can be scaled to calculate the force applied to the transducer. Sometimes a high resolution\u00a0ADC<\/a>, typically 24-bit, can be used directly.<\/p>\n

The gauges themselves are bonded onto a beam or structural member that deforms when weight is applied. In most cases, four strain gauges are used to obtain maximum sensitivity and temperature compensation. Two of the gauges are usually in tension can be represented as T1 and T2,and two in compression can be represented as C1 and C2, and are wired with compensation adjustments. The strain gauge load cell is fundamentally a spring optimized for strain measurement. Gauges are mounted in areas that exhibit strain in compression or tension. When weight is applied to the load cell, gauges C1 and C2 compress decreasing their resistances. Simultaneously, gauges T1 and T2 are stretched increasing their resistances. The change in resistances causes more current to flow through C1 and C2 and less current to flow through T1 and T2. Thus a potential difference is felt between the output or signal leads of the load cell. The gauges are mounted in a differential bridge to enhance measurement accuracy.<\/sup>When weight is applied, the strain changes the electrical resistance of the gauges in proportion to the load.<\/sup>\u00a0Other load cells are fading into obscurity, as strain gauge load cells continue to increase their accuracy and lower their unit costs.<\/sup><\/p>\n

Common types of load cells.<\/span><\/h3>\n

There are several types of load cells:<\/p>\n