Patent ID: 7752889

Claim:
A method for conducting an on-site measurement of the density or R-value of insulation material using an apparatus comprising a chamber comprising a first fluid passageway and a second fluid passageway, wherein the first fluid passageway is in fluid communication with the second fluid passageway via the chamber; and wherein the second fluid passageway is configured to engage the insulation material and to convey a gas flow to or from the insulation material; and a sensor arranged to measure the pressure in the chamber; said method comprising: measuring the pressure in the chamber while a gas flow is not being introduced into the chamber to obtain a first pressure measurement; positioning the second fluid passageway proximal to or in contact with the insulation material; introducing a gas flow into the chamber; measuring the pressure in the chamber while the gas flow is being introduced into the chamber to obtain a second pressure measurement; and determining a pressure differential based on the first and second pressure measurements.