1. **Problem:** A vacuum gauge reads 30 kPa and the barometric pressure is 755 mm Hg. Find the absolute pressure in the tank. 2. **Formula:** Absolute pressure $P_{abs} = P_{barometric} - P_{vacuum}$ for vacuum gauges. 3. **Convert barometric pressure to kPa:** - 1 mm Hg = 0.133322 kPa - $P_{barometric} = 755 \times 0.133322 = 100.66$ kPa 4. **Calculate absolute pressure:** - $P_{abs} = 100.66 - 30 = 70.66$ kPa --- 1. **Problem:** A vacuum gauge reads 5.4 psi and barometric pressure is 28.5 in Hg. Find absolute pressure. 2. **Formula:** $P_{abs} = P_{barometric} - P_{vacuum}$ 3. **Convert barometric pressure to psi:** - 1 in Hg = 0.491154 psi - $P_{barometric} = 28.5 \times 0.491154 = 14.00$ psi 4. **Calculate absolute pressure:** - $P_{abs} = 14.00 - 5.4 = 8.6$ psi --- 1. **Problem:** A pressure gauge reads 3.5 bars and barometric pressure is 75 cm Hg. Find absolute pressure. 2. **Formula:** For pressure gauge, $P_{abs} = P_{barometric} + P_{gauge}$ 3. **Convert barometric pressure to bars:** - 1 cm Hg = 0.0133322 bar - $P_{barometric} = 75 \times 0.0133322 = 1.00$ bar 4. **Calculate absolute pressure:** - $P_{abs} = 1.00 + 3.5 = 4.5$ bars **Final answers:** 1. Absolute pressure = 70.66 kPa 2. Absolute pressure = 8.6 psi 3. Absolute pressure = 4.5 bars