System and method of calibration in a powered air purifying respirator

摘要

A self-calibrating powered air purifying respirator (PAPR). The PAPR comprises an electric motor mechanically coupled to a blower; an air flow sensor, and a controller coupled to the air flow sensor and to the electric motor. The controller is configured to automatically execute a one-time self-calibration by driving the electric motor to a predefined operation point, receiving an indication from the air flow sensor, determining a reference parameter based on the indication from the air flow sensor, and storing the reference parameter, wherein after completion of the one-time self-calibration the controller controls the electric motor based on the stored reference parameter.

主权项

1. A self-calibrating powered air purifying respirator (PAPR), comprising:
an electric motor mechanically coupled to a blower; an air flow sensor; and a controller coupled to the air flow sensor and to the electric motor, wherein the controller is configured to automatically execute a one-time self-calibration by driving the electric motor to a predefined operation point, receiving an indication from the air flow sensor, determining a reference parameter based on the indication from the air flow sensor, and storing the reference parameter, wherein after completion of the one-time self-calibration the controller controls the electric motor based on the stored reference parameter; wherein the air flow sensor comprises a first probe located in an airflow channel of the PAPR to measure a stagnation pressure in the air flow channel and a second probe located to measure a static pressure in the air flow channel, wherein the all flow sensor develops the indication of air flow that comprises a difference of pressure between the first and second probes; and wherein the reference parameter is based on determining a difference between an initial value of the reference parameter and the indication of air flow, and when the difference exceeds a tolerance value, adding the initial value and the difference.