measuring wind speed?

to answer this question, actually a lot of content need to be clarified.

what wind speed measurement?

a: downdrafts, inflow air

wind speed range is how much?

a: average requirement in the marking value & plusmn; 0. 025 m/s, fluctuation range & plusmn; 20% ( From YY - 0569 Grade 2011 Ⅱ biological safety cabinet)

can be found from these content, if only a wind speed must be wrong.

blind pursuit of the wind speed is also wrong.

if you don't even know, marking value will go to ask your instrument supplier or query instrument technical documents.

: for example, if the biological safety cabinet downdrafts wind speed value is 0. 3 m/s, average should be 0. 275 - 0. Within 325 m/s, each measuring point measured value should be zero. 24 - 0. Within 36 m/s. In order to realize effective measure for the precision of the anemometer will have certain requirements, and also has specific requirements for measuring point ( The diagram below: downwash velocity measuring position requirements) 。

and into the air flow is the key to achieve effective air protection model, general requirement is bigger than down drafts, it is a major means of block pollutants once upon a time window to overflow. First of all, it is recommended to use air volume measurement test.

all in all, if the test, the demand is higher, process trival. But for daily use, impossible to complete testing, so the biological safety cabinet of the alarm system has certain requirements: once the turbulence over range, airflow patterns have no correct, timely alarm prompt.

in addition, the wind speed is not qualified, need to check the air circuit, is not necessarily the hepa filter. It is possible that the negative pressure zone internal waste too much congestion.