Abstract: A method for improving the accuracy of oxygen concentration detection comprises the following steps: in a first step, when a gas to be detected enters a gas tube, the gas tube is connected to a detection channel and the gas enters the detection channel, the detection channel being a relatively-fixed sealed space only provided with a gas inlet and outlet; in a second step, initiate an ultrasonic wave generator located at one end of the detection channel, and initiate an ultrasonic wave receiver at the other end of the detection channel; and in a third step, in a fixed time segment ranging from 0.001 s to 0.01 s, a control chip records accurate reception time in which an ultrasonic sensor sends a startup to the ultrasonic wave receiver, and calculates the oxygen concentration in the time segment by using an calculation formula.

Abstract: A locking doorknob which recognizes a fingerprint, in which the detecting sensor of a fingerprint is installed on the spot of the doorknob that a thumb or other fingers are placed naturally as the door is being opened. The locking doorknob is an electro mechanical device which can be powered by a remote electrical power system, specifically by electromagnetic induction through the door latch and strike plate. During operation, as soon as a user grasps the doorknob, a fingerprint is measured and searched and, if the fingerprint corresponds to a fingerprint previously input, the door is unlocked and the doorknob can be turned to open the door. An image capture device may also be combined with the doorknob to facilitate recognition of persons using or attempting to use the doorknob. In this way, fingerprint recognition, continuous real time security and opening of the door are performed at the same time.

Abstract: A locking doorknob recognizes a fingerprint, in which the detecting sensor of a fingerprint is installed on the spot of the doorknob that a thumb or other fingers are placed naturally as the door is being opened. The locking doorknob is an electro-mechanical device which can be powered by a remote electrical power system, specifically by electromagnetic induction through the door latch and strike plate. During operation, as soon as a user grasps the doorknob, a fingerprint is measured and searched, and if the fingerprint corresponds to a fingerprint previously input, the door is unlocked and the doorknob can be turned to open the door. In this way, fingerprint recognition and opening of the door are performed at the same time.

Abstract: The present invention relates to a locking doorknob which recognizes a fingerprint, in which the detecting sensor of a fingerprint is installed on the spot of the doorknob that a thumb or other fingers are placed naturally as the door is being opened. The locking doorknob is an electro-mechanical device which can be powered by a remote electrical power system, specifically by electromagnetic induction through the door latch and strike plate. During operation, as soon as a user grasps the doorknob, a fingerprint is measured and searched, and if the fingerprint corresponds to a fingerprint previously input, the door is unlocked and the doorknob can be turned to open the door. In this way, fingerprint recognition and opening of the door are performed at the same time.