Labconco Protector Work Stations 3930021 - Manual (Page 44)

Chapter 6: Maintaining Your Enclosure
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Guardian 500 Calibration Procedure
Each alarm module and enclosure/fume hood is unique and needs to be individually
calibrated in the field. The procedure for the adjustment is as follows:
1. Double check the installation to make sure that monitor and power supply are
properly installed.
2. Allow 10 minutes for the monitor to warm up once power has been connected.
3. Determine the low flow set point for your monitor. This is the value where the
monitor will first indicate a low flow condition. The red light will be on for this
value. Refer to your industrial hygiene officer for the proper low flow set point or
consult the table below.
4. Adjust your enclosure/fume hood airflow to the low flow set point as previously
determined. The exhaust flow can be lowered by adjusting the speed control on the
FilterMate or by using an adjustable damper on the exhaust blower. Typical alarm
conditions are set at face velocities of 10 to 20 feet per minute below the normal
operating conditions due to supply air and exhaust air fluctuations, as well as room
air cross drafts. See note 8 if the low airflow volume or sash opening cannot be
adjusted.
5. Using a properly calibrated thermoanemometer, determine the velocity through the
face of the enclosure by taking a detailed velocity traverse. Divide the face area
into equal increments. One reading per square foot of face area is normally
recommended for an accurate traverse. Compute the average velocity for this area.
Figure 6-4
Guardian 500 Details
Display
Guardian 500
Monitor