Esco® Sentinel XL™ Fume Hood Monitor measures and monitors the "face velocity" inside a fume hood. The system will generate an alarm if the face velocity drops lower than the low alarm point or rises higher than the high alarm point. The factory default for the alarm points are 0.3m/s for low alarm point and 0.7m/s for high alarm point, but these alarm points can be set to different values.
The Esco® Sentinel XL™ Fume Hood Monitor System can also monitor the sash position. The monitor system will set off an alarm when the sash position is too high (window opening is too large). This feature is not required outside Europe and can be disabled if desired.
The audible alarm can be switched between enabled or disabled with the push of a button. An LED light indicates whether or not the alarm is currently muted. The audible alarm can be disabled either temporarily or permanently. When disabled temporarily, the audible alarm will be automatically enabled again if a safe condition has been reached. When disabled permanently, the audible alarm will never be automatically enabled. The audible alarm is always enabled after each power off or reset.
A night setback switch/relay input is also provided for disabling the audible alarm. It can be useful to prevent noisy alarm from sounding at night when the exhaust duct airflow rate is usually turned down.
In addition to audible alarm, there are also LED indicators on the control panel which show the safety condition of the fume hood. A green LED will be lit when the fume hood is safe to be used. If the fume hood is not in safe condition, a red LED is lit instead.
An LCD display shows the current face velocity (can be shown in metric or imperial units), and informs whether or not it is within the safety range. When the sash monitor is activated, the LCD also informs about the unsafe sash position. The LCD backlight blinks whenever the fume hood is in an unsafe state, calling for proper attention. For convenience, the LCD also displays the current time of day.
The Esco® Sentinel XL™ Fume Hood Monitor System is also equipped with a button for a self-test procedure. Pressing this button will initiate the self-test procedure to check the condition of the sub-systems inside the monitor system.
A menu system is employed for changing the system settings and accessing the face velocity sensor calibration procedure. For security, a password can be set to limit the access to the menu.
All of the features in this monitor system will provide the user with a higher level of confidence in his or her safety when using the fume hood.