S610 Application Notes
The SMD S610 Load Cells are a family of aluminum-bodied assemblies containing a monolithic sensing element with a proprietary thin-film technology strain gauge applied, capable of producing a linear, analog voltage output in response to loadings of 0‐100g up to 100lbs depending on the model chosen.
Mounting: When used in the compression mode, this sensor should be evenly supported on the bottom surface of its body on a flat and rigid “mechanical ground” plane. The #4‐40 tapped hole provided should be used for mounting and location purposes.
Loading: Load forces may only be applied in either direction to the load button (or its #4‐40 threaded hole) of the sensor, perpendicular to its body and on the center axis of the load button. For accuracy and repeatability, a single point of contact is best. When used to measure extension forces, the sensor may be suspended between its two #4‐40 threaded holes provided the attachment feature on the active side of the sensor not interfere with the cover or sensing element. The configuration of the S610 sensor provides for inherent overload protection up to 1000% of rated capacity, therefore, no other provisions are necessary to preclude excessive deflection and damage to the sensor below that level. However, care must be taken to avoid
side loads which will cause damage to the sensor.
Wiring: Color-coded lead wires are provided for electrical connections and the cable guide spring provides an adequate form of strain relief under normal conditions.
As seen in the schematic drawing, 4 resistive elements are created by proprietary thin film technology in a Wheatstone bridge configuration and adjoining areas of strain concentration. The application of a load to the sensor causes an electrical imbalance between the resistive elements and produces an output voltage (typically in millivolts) that is linear and proportionate to the load applied. Less than the maximum excitation voltage may be used however the resulting output will be reduced proportionately.
Environment Concerns & Precautions
While the thin-film technology is itself immune to normal humidity levels, care must be taken to avoid condensing moisture and direct water exposure. The S610 is very stable over time and temperature. The robust stainless steel cover provides adequate physical protection for the thin film gage elements however, during handling and assembly procedures, anti‐static discharge practices should be observed.