Today we are going to learn more info about the terminology, to better know the weight sensor. Most strain gauge load cells work in very similar ways, but may vary in size, material, and mechanical setup, which can lead to each cell having different max loads and sensitivities that they can handle.

Deflection – The change in length along the primary axis of the load cell between no-load and rated load conditions.

Hysteresis – When a load cell is taken from zero to full load and back to zero, the mV output for a given load value will be slightly different when the load is ascending versus when the load is descending. The maximum difference is called hysteresis.

Measurements should be taken as rapidly as possible to minimize the effect of creep.

Non-Linearity – The algebraic difference between output at a specific load and the corresponding point on the straight line drawn between minimum load and maximum load. Normally expressed in units of %FS. It is common to characterize by measuring it at 40-60 %FS.

Non-Repeatability – The maximum difference between output readings for repeated loadings under identical loading and environmental conditions.

Input Resistance – The resistance of the load cell circuit measured at the excitation terminals with no load applied and with the output terminals open-circuited.

Output Resistance – The resistance of the load cell circuit measured at the signal terminals with no load applied and with the excitation terminals open-circuited.

Insulation Resistance – Normally measured at 50VDC, this is the minimum resistance between the metal body of the load cell and any of its electrical connections. Sometimes resistance is measured between the electrical connections also.

Excitation – The voltage or current applied to the input terminals of the aluminum alloy load cell. The voltage needs to be sourced from a very stable power supply otherwise it will impact the signal return. Common excitation voltages are between 5-10 VDC.