Ultrasound sensor for a fumes extractor hood
First Claim
1. An ultrasonic sensor for a fumes extractor hood with automatic compensation regarding temperature and ageing drift, said ultrasound sensor possessing a system-specific resonance frequency and comprising a transmitter and a receiver for monitoring rising cooking vapors conveyed to said fumes extractor hood;
- an electronic monitoring circuit which, at predetermined time intervals during operation of the ultrasound sensor (5), causes a frequency band of the transmission signals to sweep in the region around the resonance frequency f(o) towards both sides thereof, said monitoring circuit measuring the maximum amplitudes of generated reception signals so as to form an average frequency f(q) from the therewith associated frequencies, and utilizes said average frequency f(q) as a resonance frequency f(o) for the sensor until a successively determined change in the average frequency f(q).
1 Assignment
0 Petitions
Accused Products
Abstract
Provided is to an ultrasound sensor for a fumes extractor hood, wherein the sensor monitors the vapor rising from the cooking to the extractor hood. Automatic compensation in respect of temperature and ageing drift of the sensor is effected. For that purpose checking of the resonance frequency is implemented cyclically during on-going operation of the sensor, in which case a shift in the resonance frequency is recognized, and the new resonance frequency is established by a statistical calculation method and used for further operation of the sensor.
-
Citations
8 Claims
-
1. An ultrasonic sensor for a fumes extractor hood with automatic compensation regarding temperature and ageing drift, said ultrasound sensor possessing a system-specific resonance frequency and comprising a transmitter and a receiver for monitoring rising cooking vapors conveyed to said fumes extractor hood;
- an electronic monitoring circuit which, at predetermined time intervals during operation of the ultrasound sensor (5), causes a frequency band of the transmission signals to sweep in the region around the resonance frequency f(o) towards both sides thereof, said monitoring circuit measuring the maximum amplitudes of generated reception signals so as to form an average frequency f(q) from the therewith associated frequencies, and utilizes said average frequency f(q) as a resonance frequency f(o) for the sensor until a successively determined change in the average frequency f(q).
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
Specification