Beam imbalance

The sample cup is then precompressed by means of a spanner wrench. The resistance change of the strain elements imbalances the bridge current, providing a deflection of the potentiometer, galvanometer, or oscilloscope beam. The same electrical equipment was used to calibrate the gage. In this way, the initial precompression and pressure vs. time during impact and explosion are accurately measured. 

Actually, the beam is not brought completely to balance, but weights are removed only to the nearest whole gram or 0.1 g, depending on the balance. The imbalance of the beam is registered optically and automatically on an illuminated... 

Because the reflection beam passes through the color filter (CF) twice, while the transmission beam only passes once, generally speaking, the transflective LCD experiences an unbalanced color between the T- and R-modes. To solve the color imbalance problem, different CF approaches have been developed. Sharp Corp. proposed a multi-thickness color filter... 

Commercial instruments based on two different principles are available. One uses a vertically divided cell. The top view is shown in Figure 2.52a. One of the chambers contains a reference fluid, typically the pure solvent, and the other chamber contains the sample solution. A laser beam passes the divided cell twice before reaching a two-part photodetector. The detector is placed so that the beam hits the two parts equally when the two chambers of the cell have the same refractive index. A difference in the refractive index in the chambers deflects the beam, resulting in unequal intensities on the two parts of the detector. Thus the imbalance of the two intensities gives the refractive index difference An. 

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