Automatic zero point correction device for a pressure sensor, a pressure control device and a pressure type flow rate control device

摘要

The invention provides an automatic zero point correction device that includes a pressure sensor, wherein output from the sensor is outputted and the sensor output is inputted to a time-varying zero point drift correction means of the sensor; a sensor output judgement means of the time-varying zero point drift correction means, wherein the sensor output judgement means operates to make a judgement determining whether the sensor output is larger than a set value; and operating condition judgement means of the time-varying zero point drift correction means, wherein the operating condition judgement means judges operating conditions of the sensor, wherein the time-varying zero point drift correction means operates to cancel time-varying zero point drift of the sensor when the sensor output judgement means determines sensor output is larger than the set value and the operating condition judgement means determines operating conditions of the sensor are within previously set operating conditions.