US 12,320,711 B2
Method for calibrating a temperature measuring unit based on ultrasonic measurement, method for measuring the temperature of a medium, temperature measuring unit and ultrasonic flowmeter
Cornelis Johannes Hogendoor, BG Spijk (NL)
Filed by KROHNE AG, Basel (CH)
Filed on Jan. 7, 2022, as Appl. No. 17/571,111.
Claims priority of application No. 10 2021 101 256.2 (DE), filed on Jan. 21, 2021.
Prior Publication US 2022/0228930 A1, Jul. 21, 2022
Int. Cl. G01K 11/24 (2006.01); G01N 29/024 (2006.01)
CPC G01K 11/24 (2013.01) [G01N 29/024 (2013.01); G01N 2291/02881 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method for calibrating a temperature measuring unit based on ultrasound measurement, wherein the temperature measuring unit includes a temperature sensor and an ultrasound measuring device with at least one ultrasound transmitter and at least one ultrasound receiver, the method comprising:
establishing an empirical functional relationship TM(c) between a medium temperature TM of a medium to be measured and a sound velocity c of a measurement signal, emitted by the at least one ultrasound transmitter and received by the at least one ultrasound receiver of the ultrasound measuring device, and passing through the medium to be measured, comprising:
capturing, at a first measuring point, a first sound velocity c1 of the measurement signal by means of the ultrasound measuring device and a first sensor temperature measured by means of the temperature sensor;
capturing, at a second measuring point, a second sound velocity c2 of the measurement signal by means of the ultrasound measuring device and a second sensor temperature measured by means of the temperature sensor, wherein the first measuring point differs from the second measuring point and wherein the first sensor temperature and the second sensor temperature are different;
determining a first medium temperature TM1 from the first sensor temperature and a second medium temperature TM2 from the second sensor temperature using a time variation of the sensor temperature dT/dt, to generate at least two pairs of values (TM1, c1) and (TM2, c2);
determining a compensating curve through the at least two pairs of values to generate the empirical functional relationship TM(c); and
storing the empirical functional relationship TM(c) in the temperature measuring unit.