Enquire Now! Contact Us ISO9001 Certified Twitter Facebook LinkedIn Youtube Email Coefficient of Variation (CoV) Coefficient of Variation (CoV) When two fluids are mixed in a pipe or channel, the quality of the radial mixing (across the pipe or channel) can be described statistically by the coefficient of variation, CoV, which is defined as: Where: ci = is the difference between the background concentration and that of the flow plus additive cave = is the c averaged for each of the probes n = is the number of positions where concentration is measured cmean is the mean concentration of each of the probes ∑ is the sum of all the terms in brackets i.e. In a radial mixing device such as an empty pipe or channel, the CoV describes the deviations of local concentrations from the mean within a cross section of the pipe or channel. Assuming a normal distribution, the following approximately applies: About 2/3 of the values will lie within c(1 ± CoV) About 95% of the values will lie within c(1 ± 2CoV) About 99.75% of the values will lie within c(1 ± 3CoV). The lower the value of CoV, the better the mixture quality. The required level of mixture quality is usually process specific. However, a CoV of between 0.01 and 0.05 is a reasonable target for most applications. This means that 95% of all concentration measurements to be taken from the pipe or channel cross section will be within ±2% of the mean concentration for CoV=0.01 and ±10% for CoV=0.05. The photographs below illustrate different mixture qualities over a 5D distance from the dosing point: CoV = 0.03 Good mixing CoV = 0.18 Poor mixing Reproduced with the kind permission of BHR Group Ltd. Search Search Submit Latest News Statiflo Spreads Across Africa November 25, 2021 Statiflo Wins Award for Exporting Excellence November 3, 2021 Statiflo’s Team Find Successful Formula for CHEMUK 2021 September 27, 2021 Back on the Road! Statiflo are Heading to CHEMUK 21 July 15, 2021 Statiflo Makes Waves with New Scottish Water Deal July 7, 2021 Latest News Statiflo Spreads Across Africa November 25, 2021 Statiflo Wins Award for Exporting Excellence November 3, 2021 Statiflo’s Team Find Successful Formula for CHEMUK 2021 September 27, 2021 Back on the Road! Statiflo are Heading to CHEMUK 21 July 15, 2021 Statiflo Makes Waves with New Scottish Water Deal July 7, 2021 Contact Us Statiflo International +44 (0) 1625 433 100 enquiries@statiflogroup.com Statiflo Corporation +1 (413) 684 9911 enquiries@statiflogroup.com Statiflo GmbH +49 (0) 2261 913570 enquiries@statiflogroup.com Statiflo Inc. +1 (416) 756 2406 enquiries@statiflogroup.com Latest News Statiflo Spreads Across Africa Statiflo Wins Award for Exporting Excellence Statiflo’s Team Find Successful Formula for CHEMUK 2021 Social Tweets by Statiflo Copyright Statiflo Group - All Rights Reserved You can learn more about cookies at AboutCookies.org. If you wish to stop cookies, or find out more about how we use them, click here.