Labconco Fume Adsorbers 3955422 - Manual (Page 24)

Chapter 6: Maintaining Your Enclosure
Product Service 1-800-522-7658 20
Detection Tubes - Color change indicators can be used to measure the
concentration of the chemical at the exit side of the carbon filter or in the outlet
exhaust. A kit including syringe pump and flexible tubing can be purchased as an
accessory from Labconco (Catalog # 6924900). Labconco Customer Service
Representatives are supplied with detector tube catalog numbers, as well as
telephone numbers to direct you to where to purchase these items.
For Organic, Formaldehyde and Ammonia, chemical specific detector tubes should
be purchased when installing fresh filters. Each kit contains instructions on how
many strokes of the syringe are required to obtain the stated sensitivity. The
sampling syringe is connected to the filtered enclosure exhaust. There is a 5/16"
diameter hole on the upper right side for inserting the detector tube. Connect the
syringe to the detector tube while the system is running and pull the air through the
tube with the syringe. Each stroke of the syringe represents a 100-ml sample and
corresponds to the number of strokes necessary to give the indicated color changes.
Due to the wide variety of organics and varying TWA’s, it is recommended that
specific detector tubes be purchased directly from Sensidyne, Draeger or your
laboratory supply dealer. Alternate detector pumps can also be purchased from
your laboratory supply dealers. The vast majority of detector tubes available start
measuring at the TWA. When a user observes a color change in the tube, they
should replace the filter immediately. If no detector tube for your specific
chemical is available, other means of detection must be used.
Time - For applications that have very consistent inlet concentrations and
operating time, “Time” can be used to anticipate saturation or TWA levels based
on prior experience. However, this does not replace the need for sampling.
Consult Labconco technical specialist for an estimate of carbon filter life based on
chemical usage. Detector tubes, or analytical instrumentation should always be
used to determine concentrations in the carbon filter. It is recommended that the
carbon filters be checked with detector tubes or other means at intervals of 20% of
the total estimated filter life. The exception to the 20% recommendation is
formaldehyde and any carcinogen or suspected carcinogen. These more hazardous
chemicals must be checked at least every 10% of the total estimated time.
Analytical Instrumentation - This is the most accurate means of measuring
concentrations of any chemical. It is the method of choice when no detector tubes
are available or the tubes are not sensitive enough to measure at the TWA
concentration for the chemical. This method is also to be used to determine
saturation when the chemical concentration is below the measurement range of
detector tubes.
Carbon Filter Replacement Procedure – See Figure(s) A-2 and A-3 in Appendix
A for Carbon Filter Replacement.
Do NOT contact blower wheel while still in motion.
NE PAS être en contact avec la roué du ventilateur tant qu’il est
en marche.
!