What’s a thorough examination and test?

Companies that have installed local exhaust ventilation systems have to undertake a “thorough examination and test” (TExT) at least once every 14 months. The objective of the TExT is to find any significant defects and to have them remedied to regain control. In most cases they will employ an external organisation to carry out theseContinue reading “What’s a thorough examination and test?”

Testing walk-in spray booths

We recently received a query from a client who carry out paint spraying of isocyanate based two pack paints in a large walk-in type spray booth. They wanted us to carry out sampling to help them to decide when it was safe to enter the booth without their workers wearing their air fed masks. ThisContinue reading “Testing walk-in spray booths”

What is “static pressure”?

We were running the BOHS module course P601 “Commissioning and Thorough Examination and Testing of Local Exhaust Ventilation Systems” last week. One of the concepts delegates often find difficult to get to grips with is “static pressure”, which is one of the main engineering measurements carried out during the testing of a local exhaust ventilationContinue reading “What is “static pressure”?”

Visualising Airflow

It can be difficult to make a qualitative evaluation of the effectiveness of LEV hoods because the contaminants are either invisible (in the case of most gases and vapours) or difficult to see (with fine dusts). Two main techniques can be used to overcome this problem: smoke tests dust lamps Smoke released in the vicinityContinue reading “Visualising Airflow”

Testing LEV systems when baseline data isn’t available

One of the main problems we encounter when carrying out a thorough examination and test of a local exhaust ventilation (LEV) system is the lack of “baseline data” – i.e. information on what the pressures and velocities should be when the system is operating in accordance with the design specification. Providing the system has beenContinue reading “Testing LEV systems when baseline data isn’t available”

P601 – Competence in LEV testing

I received the following query a few days ago: A large part of my working life during the last 14 years has been involved with the Thorough Examination and Test of Local Exhaust Ventilation (LEV) systems within the company I work for. I have now moved on within the same company to a health and safety position,Continue reading “P601 – Competence in LEV testing”

The joys of LEV testing – Part 1

I’ve been out on site this week with Deb, getting our hands dirty doing some ventilation testing. A number of the systems were quite large, with several hoods and branches. Most of the hoods couldn’t be reached when the process is operating due to safety considerations. This makes testing difficult. It’s only possible to measure face andContinue reading “The joys of LEV testing – Part 1”