关于毛细管粘度计一点法公式的探讨

毛细管粘度计结构简单,测量方便,被广泛用来测量液体的粘度(牛顿液体和某些非牛顿液体)。例如,高分子化学、高分子物理、物理化学中,通过测量粘度以确定聚合物的分子量;化学工业、物理实验及血液研究中,用来测量液体和血液的粘度。用毛细管粘度计测液体粘度的方法有二:     

单板机在粘度测量实验中的应用

单板机在粘度测量实验中的应用韩玖荣，詹鼎（扬州大学２２５００１）一、引言在大学物理实验中，特别是农业院校一般都有粘度测量这个实验．液体粘度的测量有多种方法，旋转法、毛细管法、落球法，最近还有人制成功了超声粘度计［１］。在学生实验中，一般采用毛细管法和...     

奥氏粘度计原理的简单证明

奥氏粘度计原理的简单证明陈百万（山东潍坊医学院２６１０４２）用奥氏粘度计（如图所示）采用比较法测量液体粘度的公式是式中η０、ρ０分别为标准液体的粘度和密度，η、ρ分别是待测液体的粘度和密度，ｔ０和ｔ分别是一定体积的两种液体流过竖直毛细管所用的时间．一...     

甲醇与蓖麻油混合物运动粘度的实验研究

利用改型的乌别洛特毛细管粘度计,本文对243～353K温度范围内对质量配比为98.8:1.2的甲醇与蓖麻油混合物的运动粘度进行了实验研究,运动粘度测量结果的不确定度为1.06%,利用得到的实验数据拟合了甲醇 蓖麻油二元混合物的运动粘度方程.方程与实验数据最大偏差为3.31%,平均偏差为1.11%.     

可动毛细管粘度计

一、前言在各种各样的粘度计之中,毛细管粘度计能够进行粘度(粘滞系数)的绝对测定,并且用比较简单的装置可以得到精度较好的测定。历来的毛细管粘度计,归根结底是通过压差或液头差以及流量来得到粘度的一种方式。此处介绍的毛细管粘度计,是具有把毛细管的两端用可动接头与固定管连接起来的构造,力测定方式的粘度计。这种力测定方式的毛细管粘度计也和上述的压差测定方式的粘度计有着同样的长处。     

气泡对液体粘度测量的影响

讨论了用奥氏粘度计测量液体粘度过程中,气泡对测量结果的影响,指出在用此法测量液体的粘度时,应注意选择粘度计,注入适量的液体,并排除气泡才能使测量结果准确无误。     

碳酸二甲酯与柴油混合物粘度的实验研究

利用密度瓶和玻璃毛细管粘度计,本文对293~353 K温度范围内的碳酸二甲酯与柴油混合物的密度与粘度进行了实验研究,得到了不同配比下碳酸二甲酯与柴油混合物的密度与粘度实验数据。利用得到的实验数据,拟合了不同配比下的碳酸二甲酯与柴油混合物的密度与粘度计算方程。根据Grunberg-Nissan方法,最终得到了混合物粘度的计算方程,此方程适用于碳酸二甲酯的比例不超过20％的情况,分析表明计算结果与实验数据的偏差小于5％,可以满足工程实际应用的需要。     

振动弦粘度计研制及MTBE饱和液相粘度实验研究

本文研制了一套高精度振动弦粘度计,测量不确定度为士2%.用新研制的粘度计,对293.15～383.15 K温度区间内的甲基叔丁醚(methyl tert-butyl ether,MTBE)饱和液相粘度进行了实验研究.利用本文实验数据拟合了甲基叔丁醚饱和液相粘度方程,方程和实验数据的平均和最大相对偏差分别为0.49%和1.21%,可以满足工程实际应用.     

声波粘度传感器

A.J.Ricco和S.J.Martin报道了一种声波粘度传感器.通常的粘度计需要相当大的被测液体体积,或者具有运动部件,这在现场应用是不便的.本文介绍的声波粘度传感器,只需要10μl或更少的被测液体体积便可测量其粘度.     

智能型落针粘度计

智能型落针粘度计沙振舜，张荫千（南京大学物理系）（南京通信工程学院）一、引言粘度是流体的重要物理性质，粘度的测量在许多领域日益受到重视．目前测量流体粘度的仪器不下２００种．在各类高校的物理实验室中，几乎都开设了液体粘度测量的实验，落球法因其特别简单而...     

Determination of the adsorbed layer thickness of polystyrene on glass surface by viscosity measurements to the extremely dilute concentration region

A newly developed theory regarding solute adsorption effect in viscometry of a polymer solution is reviewed and extended for determining the adsorbed layer thickness of polystyrene on a glass surface in viscosity measurements. This theory can adequately describe the concentration dependence of the viscosity of a polymer solution measured by glass capillary viscometer to the extremely dilute concentration region. Using this theory, both the free polymer chains in solution and the adsorbed polymer chain on the viscometer inner wall surface can be characterized. Examples are given for the characterization of six polystyrene samples with different molar masses by measuring their solution viscosity in benzene.     

Shear viscosity of polymer and surfactant monolayers

The surface shear viscosity of monolayers formed at the surface of water by adsorbed polyethyl- eneoxyde and by stearic acid is measured as a function of the surface pressure of the monolayer using a new surface viscometer. The principle of the viscometer is the measurement of the drag force on a circular disk undergoing a uniform translation at the water surface: a hydrodynamic model based on the lubrication approximation allows a calculation of the surface viscosities from the absolute measurement of the drag forces. Received: 26 August 1999     

Shear flow of a heterophase liquid interlayer and its structural-rheological model

The shear flow of micrometer n-hexadecane interlayers is studied using a rotary viscometer. The viscosity of the flow in such interlayers differs from the viscosity of the liquid in the bulk, which is measured by capillary viscometers. This is due to the fact that surface structured layers with different viscosity play a significant role in thin interlayers. To describe the features of the flow of an inhomogeneous interlayer including such layers, its rheological models is considered, in which molecules in the layers are reoriented by the flow; accordingly, their viscosity is determined by the strain rate. The model is used to calculate the parameters of the structured layer.     

Theory of the Greenspan viscometer

We present a detailed acoustic model of the Greenspan acoustic viscometer, a practical instrument for accurately measuring the viscosity eta of gases. As conceived by Greenspan, the viscometer is a Helmholtz resonator composed of two chambers coupled by a duct of radius rd. In the lowest order, eta=pi f rho(rd/Q)2, where f and Q are the frequency and quality factor of the isolated Greenspan mode, and rho is the gas density. In this level of approximation, the viscosity can be determined by measuring the duct radius and frequency response of the resonator. In the full acoustic model of the resonator, the duct is represented by a T-equivalent circuit, the chambers as lumped impedances, and the effects of the diverging fields at the duct ends by lumped end impedances with inertial and resistive components. The model accounts for contributions to 1/Q from thermal dissipation (primarily localized in the chambers) and from a capillary used for filling and evacuating the resonator. A robust, prototype instrument is being used for measuring the viscosity of reactive gases used in semiconductor processing. For well-characterized surrogate gases, the prototype viscometer generated values of eta that were within +/-0.8% of published reference values throughout the pressure range 0.2-3.2 MPa. Remarkably, we achieved this level of agreement by only slight adjustment of the numerically calculated inertial and resistive end effect parameters to improve the agreement with helium reference values. No other parameters were adjusted.     

磁流体粘度的实验研究

采用毛细法粘度计测量了水基Fe磁流体的粘度,分析了磁性粒子份额、表面活性剂含量以及外加磁场强度和方向对粘度的影响。实验结果表明,磁流体粘度随着磁性粒子和表面活性剂浓度的增加而增加;随着外加磁场强度的增大而增大,对于相同的磁流体,在外加磁场方向垂直于流动方向时的粘度大于外加磁场方向平行于流动方向时的粘度;表面活性剂含量的增大将减弱外加磁场对磁流体粘度的影响。     

用毛细管成像法测量液相扩散系数——等折射率薄层测量方法

本文提出了一种测量液相扩散系数的新方法. 该方法用透明毛细管构成液相扩散池, 利用毛细管成像法特有的折射率空间分辨测量能力, 通过直接观察和记录扩散介质的等折射率薄层在毛细管中的移动规律, 基于扩散过程遵循的Fick第二定律计算出液相扩散系数. 在25 ℃下研究了丙三醇和纯水间的扩散过程, 扩散系数的测量值与全息干涉法的文献报道值之间的相对误差为4.47%, 论文同时分析了折射率测量精度和毛细管管壁黏滞力对扩散系数的影响. 用毛细管成像法测量液相扩散系数具有样品需要量少、测量速度快、系统稳定性好的特点, 为快速测定微量样品的扩散系数提供了一种有效的新方法. 关键词： 扩散系数 液体折射率 毛细管成像法     

Calculation of the Viscosity of Polymer Melts Based on Measurements of the Recovered Rubber-Like Deformation

On the basis of a model of polymer flow, considering the forces of entropic elasticity of extended macromolecules within the Eyring's concept, the relationships between the shear rate, shear stress, viscosity, and recovered rubber-like deformation were derived. The reduction of activation energy of the flow, by an amount proportional to the recovered rubber-like deformation, leads to an exponential decrease of viscosity with increasing shear rates; this nonlinear dependence of viscosity on shear rate (and shear stress) is defined as the viscosity anomaly of polymers. The measurement of deformation recovery after the cessation of polymer flow in the mode of constant shear rate or shear stress on a rotational viscometer confirmed the validity of the theoretical dependences.     

毛细管两端压强差对液体粘度测量的影响

利用毛细管法测定水的粘度,探讨了毛细管两端不同压强差对水粘度测量的影响。结果表明不同压强差对测量粘度有一定的影响,压差的减小使测量结果的误差增大,与理论相符。