Review on 🔍 Pressure Sensors: Stainless Steel, Liquid-Filled Instruments by Robert Ryokan

Made it to -29 inches once and as the system equalized to atmospheric pressure the needle returned to -10. I pressed the top rubber vent lightly to even out the reading and the needle went back to -5. On the next use the needle went through 30 and almost to zero. I know my pump can go down to about -29.25 inches. So when the needle stops moving, I know I'm there, but a lot can change between 29 and 29.25, so it's relatively useless.