What should I be googling in order to pick up a range of suppliers of retro-fit airflow meters? I've found loads of LEV testing sites which rehash or direct you to the HSE guidance, but very few concrete examples of the type of equipment which might be fitted....or its price. Our LEV systems are in woodworking, metalworking and ceramics workshops, used sporadically. Does anyone have examples of retro-fits which went well, or any problems to anticipate? Many thanks Clare H

I think this will depend on the type of system and the level of hazard it controls. For example magnahelic gauges or manaometers may be used in some high risk systems, flow meters and alarms on others eg. fume cupboards. But on low risk items such as welding hoods (weld fume only) or joinery fixed machine LEV the fitting of these expensive items may not be pratical or cost effective. "'Tell-tales" such as pieces of string or paper stuck to the LEV hood will not provide a suitable/sufficient indication of airflow. However you can buy low cost (albeit low accuracy) hand held mini anemometers which can be used by the LEV user to measure the flow rates and make a daily or pre-user check which should be recorded and used as a guide to when performance is/has decreased and maintenance or filters need changing. We use a product caled a "Kestrel" anemometer ~£80: http://uk.rs-online.com/web/p/anemometers/2339546/ Im sure other manufacturers and suppliers would be just as good. Hope this helps Des

Can anyone recommend equipment for monitoring airflow on LEV systems that is not a handheld anenometer? Unfortunately the design of our LEV system will not allow easy use of such an anenometer but we still want to monitor that airflow regularly because the design of the LEV ducting and the nature of the material we generate means that the airflow can be affected between 14 monthly examinations. We looked at a hot wire anenometer but our examiner advised us against using it - he seemed to doubt the accuracy would be within acceptable limits? Thanks Lucy

I differentiate between 'performance' and 'effectiveness'. To give an example, I recently surveyed a workplace where there was a considerable amount of LEV. This has all been checked prior to my visit and was performing to specification. However, when I checked its effectiveness, i.e. was it really removing the contamination to a level where the operator was not exposed, virtually none of the LEV systems were achieving the necessary 'capture'. This was largely due to inadequate design of the capture systems. To carry out the test I used the simple 'smoke tube'. This produces a small amount of chemical smoke. If this is then puffed out into the work area and is not immediately drawn into the LEV system, then irrespective of air velocity, the system is ineffective. Incidentally, I have found this simple, low cost, method ideal for demonstrating to management the need to uprate the effectiveness of the LEV systems.

Thanks for the suggestions - I will investigate further! Lucy

A wee bit more background as to why you want this retrofit might help. It could be as simple as drilling and epoxy of some capped spigots to enable a hot wire anemometer to be inserted at critical points of the system. You could hire a calibrated anemometer for the brief periods you'd need it, or leave that to the competent person that does your COSHH LEV check?