8) ) 2.8 EIGURE 2.76 shows a Boyle's low prosineler nully ted to determine grain volume in routine core analysis. The operation of the instrument is as follows: The sample is placed in the sample clumber and vented to the atmosphere The sample chamber is sealed The reference chamber is pressurized by means of helium The shut-off valve is closed Once the system comes to equilibrium, the gauge pressure in the reference charger Plein recorded The three-way valve is opened between the reference chamber and the sample chatber . Once the system has re-equilibrated the grase pressure (Ps) is recorded The instrument was calibrated with steel spheres with the results shown in TABLE2.IO. Sphere Diameter P. (cm) (psig) (psig) 5.816 100 70 5.523 100 50 4.680 100 30 TABLE 2.10 - Calibration data for Boyles law Porosimeter P24 FO V. TIES d. Determine the porosity of a cylindrical core sample, 3.4 inches long and 1.5 inches in diameter, given that the equilibrium P2was 52 psig when a measurement was performed with the sample at the same Pig as in the calibration tests