| 摘要 |
<p>The viscometer (100) includes a difference amplifier (110) driven by a signal generator (111) which supplies a control signal to shaker (120), which is sufficiently powerful to impose such strains as may be demanded by a controlling reference voltage with a desired form. The shaker (120) drives a shaft (125), and an upper plate (130) is attached to a distal end of the shaft (125). A lower plate (140) is positioned adjacent, and substantially parallel to, upper plate (130), thereby creating a space that may be filled by fluid sample (150). The motion of the upper plate h(t) is measured by a sensor (180). Plate (140) is mounted on force measuring means (160) which keeps lower plate (140) substantially motionless relative to frame (165). Force measuring means (160) provides an output, or force, signal f(t) that is indicative of the force which fluid sample (150) exerts on plate (130 and 140) in response to the movement of upper plate (130). This force is related to the viscosity of fluid sample (150) by the equation G*(φ) = h3/3πa4 F(φ)/H(φ), where G*(φ) is the complex modulus, F(φ) is the Fourier transform of f(t), H(φ) is the Fourier transform of h(t), a is the radius of the plate (130), and h is the mean distance between the plates (130 and 140).</p> |
