Flexures, weighing

Fig. 10. Cross section of an EMFC weighing cell. Item 1, pan 2, hanger 3, parallel guide 4, chassis 5, flexure 6, lever 7, flexible link 8, pivot point 9, position indicator 10, position sensor 11, permanent magnet 12, permanent magnet air gap 13, compensation cod. See text.

The flexural pivot is free of the problems associated with the knife edge. However, it can act as a spring and therefore may add an extra force to the weighing process. This force may artificially subtract from an object s true mass and provide inaccurate readings. This effect may arise as a result of time or as temperature changes. Manufacturing design may decrease this effect, and it may also be... 

An electronic balance based on a parallelogram flexure support and an electromagnetic force cell. The flexure points allow limited movement about the null position and provide resistance to torsional distortion by off-center loading of the weighing pan. Drawing taken from Ref. 3 with permission. 

R.H. chamber. These data were generally close to the room temperature immersion results, and with one exception are not reported here.) The flexural modulus of the specimen was also measured at the time of weighing, since the absorbed water acted to plasticize the cured resin. 

A plastic block is weight-loaded against the rim of the disk (line contact) and the wear test is usually between 20 and 30 hours. The plastic samples have dimensions that allow them to be made from plastic flex test bars that are commonly molded out of new plastics to measure their flexural properties. This test is intended to replace the thrust washer test. The ASTM test procedure does not require measurement of counterface wear, but it is always advisable to make this measurement. The disk weighs more than 3 kg, making it difficult to weigh it to measure mass change that occiured in a test Profilometry could be used. 

---