Effects of flow disturbances on an ultrasonic gas flowmeter
1992 (English)In: Flow Measurement and Instrumentation, ISSN 0955-5986, E-ISSN 1873-6998, Vol. 3, no 4, 227-233 p.Article in journal (Refereed) Published
A series of tests are carried out to assess the effects of flow disturbance on a small dimension ultrasonic gas flowmeter. Flow disturbances generated by cone couplings, and single and double elbows are investigated. Measurements with a 100 D straight pipe upstream with a smooth connection to the meter body are used as a reference. Our measurements show that the symmetrical disturbance produced by a cone coupling at a 12 D distance from the transducer path does not impair the performance of the flowmeter. An asymmetrical disturbance, such as a single or a double elbow at the same distance, seems generally to give an underestimation of the flow velocity, resulting in reading errors of -1% or worse. Measurements with straight pipes of 10 D, 20 D, 40 D and 80 D between the disturbance and the flowmeter have also been made showing that 10 D can cause an overestimation of flow velocity. Increasing the length of the straight pipe generally decreases the error. More than 80 D straight pipe between the disturbance and the flowmeter is required to give a result within ±1% of reference conditions. The angle between the elbow plane and the transducer plane is changed from 0 to 315° in 45° steps. The meter error is plotted as a function of inlet angle, showing a clear relationship between these values.
Place, publisher, year, edition, pages
1992. Vol. 3, no 4, 227-233 p.
Research subject Industrial Electronics
IdentifiersURN: urn:nbn:se:ltu:diva-6926DOI: 10.1016/0955-5986(92)90020-6Local ID: 541d2870-d872-11db-a1bf-000ea68e967bOAI: oai:DiVA.org:ltu-6926DiVA: diva2:979812
Upprättat; 1992; 20070322 (pekkari)2016-09-292016-09-29