Patent ID: 7608138

Claim:
A filter pressure loss measuring apparatus for measuring the differential pressure (pressure loss) of a fluid, which occurs when the fluid passes through a filter having an inflow end face through which the fluid enters and an outflow end face through which the fluid is discharged, the apparatus comprising filter holding means capable of holding the filter; fluid passing means for causing the fluid to pass through the filter; flow rate measuring means for measuring the flow rate of the fluid which passes through the filter; pressure loss measuring means for measuring the pressure loss of the fluid, which occurs when the fluid passes through the filter at a flow rate as measured through the flow rate measuring means; a flow path which connects the aforementioned four means such that the fluid can pass between the means; and flow rate regulating means for regulating the flow rate so as to maintain a constant level, the flow rate regulating means having a tributary path which is branched from the flow path (mainstream path) and communicates with the outside, and one or more flow path opening/closing members capable of, in conjunction with the level of the fluid flow rate as measured through the flow rate measuring means, opening or closing the mainstream path or the tributary path such that the flow path opening ratio of each of the paths varies continuously or intermittently, whereby the pressure loss is measured while the flow rate of the fluid which passes through the filter is maintained at a constant level by the flow rate regulating means.