Hi Ken,
Sorry about the delay in getting back to you! Gazzaa is right about the old E70D Xenon detectors becase the sensitivity is unajustable they are not the right VESDA unit to use in a dirty environment with losts of air bourne debris. Also on a side note all of the Xenon detectors are now obsolete and we no longer support those types, we are offering an incentive for any xenon upgrades to our new detectors if people are interested.
Off the top of my head I cannot remember any circumstances where VESDA units have been used to protect areas that include cement works specifically. We have however had successful installations within a paper recycling facility which creates a huge amount of paper dust in the environment with out any problems. The detection sensitivity threshold will definately be set towards the lower end of the range. All I would suggest is to set the system for a autolearn period to establish what the general background dust levels. Fomr this you should be able to minimise false alarms but setting your alert, alarm and fire thresholds to suit the envirnment. Also remember that in these dirty environs the VESDA filters will need to be replaced at regular intervals to remain effective.
I hope this helps! Any questions just email me.
Kevin Shea
Xtralis Lts
KShea@xtralis.com