| | | This document defines the terminology and performance parameters pertaining to engineering specifications of load cell products. The objective of this terminology standard is to promote effective communication of specifications and to constitute a reference for uniformity. The definitions herein are generally compatible with common understanding in the load cell community and are an expansion of those found in "Load Cell Terminology and Test Procedure Recommendations", Third Edition, 1985, Scale Manufacturers Association, and in OIML International Recommendation R60, 1991 Edition. This document includes modifications to the definitions in the above referenced standards to correct some of their inconsistencies and inadequacies. For convenience, terms which are defined in this standard are printed in italics when used in the definition of another term.=============================================================================== | | |
| | | AMBIENT TEMPERATURE The temperature of the medium surrounding the load cell. AXIAL LOAD A load applied along the primary axis. BAROMETRIC SENSITIVITY The change in zero balance due to a change in ambient barometric pressure. Normally expressed in units of %RO/atm. CALIBRATION The comparison of load cell output against standard test loads. CAPACITY The maximum axial load a load cell is designed to measure within its specifications. COMBINED ERROR The maximum deviation of the calibration curve from the straight line drawn between minimum load output and maximum load output, normally expressed in units of %FS. Both ascending and descending curves are considered. CREEP The change in load cell signal occurring with time while under load and with all environmental conditions and other variables remaining constant. Normally expressed in units of % of applied load over a specified time interval. It is common for characterization to be measured with a constant load at or near capacity. CREEP RECOVERY The change in load cell signal occurring with time immediately after removal of a load which had been applied for a specified time interval, environmental conditions and other variables remaining constant during the loaded and unloaded intervals. Normally expressed in units of % of applied load over a | | specified time interval. Normally the applied interval and the recovery interval are equal. It is common for characterization to be measured with a constant load at or near capacity. CREEP RETURN The difference between load cell signal immediately after removal of a load which had been applied for a specified time interval, environmental conditions and other variables remaining constant during the loaded interval, and the signal before application of the load. Normally expressed in units of % of applied load over a specified time interval. It is common for characterization to be measured with a constant load at or near capacity. DEFLECTION The displacement of the point of axial load application in the primary axis between the MDL and MDL+capacity load conditions. ECCENTRIC LOAD Any load applied parallel to but not concentric with the primary axis. FULL SCALE or FS The output corresponding to maximum load in any specific test or application . HYSTERESIS The algebraic difference between output at a given load descending from maximum load and output at the same load ascending from minimum load. Normally expressed in units of %FS. It is common for characterization to be measured at 40-60 %FS. 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. INSULATION RESISTANCE The DC resistance measured between the bridge | | |