초록 ▼

A working fluid of a mechanical system is analyzed by measuring the permittivity of the working fluid as the temperature of the working fluid is varied over a range. Within this temperature range, a special temperature is identified, at which the rate of change of the permittivity over temperature i

A working fluid of a mechanical system is analyzed by measuring the permittivity of the working fluid as the temperature of the working fluid is varied over a range. Within this temperature range, a special temperature is identified, at which the rate of change of the permittivity over temperature is at a maximum. Subsequently, the viscosity, acid content, moisture content and density of the working fluid are determined from the special temperature, rate of change of permittivity at the special temperature, permittivity of the special temperature, and rate of change of permittivity above the special temperature, respectively. To ensure accurate determination of the special temperature and other parameter values, a curve-fitting technique is used, in which measurements of permittivity over the temperature range are fitted to a mathematical model of the expected curve, and this mathematical model is used to identify the various parameter values. Apparatus for performing this analysis method may be in the form of a desk-top oil analyzer for use in an on-site application, or an integrated analysis device suitable for mounting directly to the mechanical system, e.g., in the form of an adapter insertable between the oil filter and oil filter mounting. The working fluid being analyzed may be oil, hydraulic fluid, or any other fluid used in a mechanical system which is subject to contamination and degradation.

대표청구항 ▼

1. A method for analyzing a working fluid to determine the viscosity of the working fluid, comprising the steps ofmeasuring the permittivity of the working fluid while varying the temperature of the working fluid over a temperature range, the temperature range including a special temperature at whic

1. A method for analyzing a working fluid to determine the viscosity of the working fluid, comprising the steps ofmeasuring the permittivity of the working fluid while varying the temperature of the working fluid over a temperature range, the temperature range including a special temperature at which the rate of change of the permittivity over temperature is at a maximum, identifying the special temperature from variation in the permittivity of the working fluid over temperature, converting the value of the special temperature to a measure of viscosity of the working fluid.