Influence of water temperature on results of current meter calibration and measurement

Title:

Influence of water temperature on results of current meter calibration and measurement

Creator:

Mattas, Daniel and Ramešová, Libuše

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:83ce70e2-02c3-43cc-a646-72bdef62e6ac
uuid:83ce70e2-02c3-43cc-a646-72bdef62e6ac
doi:10.2478/johh-2013-0027

Subject:

current meter, measurement uncertainty, and water temperature influence

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

On the basis of the results of calibration of current meters at water of varying temperatures, a hypothesis that water temperature influences measured water velocities was formulated. The analysis of our long-term data showed that the water temperature does have an influence on measured water velocity. This influence can be taken into account for practical purposes as a contribution to the uncertainty of measurements. The influence depends on the type of current meter propeller. This paper presents results obtained for the Ott C-2 current meter with propellers of the types 1, 2, 3, 5 and 6. Our analysis showed that the uncertainty is equal or less than 5% for measurements carried out in water with temperatures above 8°C. The differences between measured water velocities for water temperatures 5°C and 20°C reached maximum 6% (depending on the propeller) in a slowly flowing water (rotational frequency n = 1 s-1 ). For rotational velocity n ≥ 2 s-1 the differences between velocities measured at water temperatures 5 and 20°C were mostly under 3%. The less influenced propeller is of type 3 for which the uncertainty of measurement does not reach 5% even for water temperature 1ºC if the rotational frequency is bigger than 0.7 s-1 .

Language:

Slovak

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

208-213

Source:

Journal of hydrology and hydromechanics | 2013 Volume:61 | Number:3

Harvested from:

CDK

Metadata only:

false