Multi-Method Gas Detection
Independence™ ductless fume hood provides four methods for filtration monitoring and gas detection. This feature is possible due to the powerful AirClean® Operating System.
The four methods are:
- PID gas analyzer
- Metal oxide array
- Acid array
- Colorimetric gas sampling tubes
The PID gas analyzer in connection with Independence™'s extensive chemical database and reference library allows for exact monitoring and readout of gas levels in PPM.
The metal oxide array is sensitive to a range of hydrocarbons and used only in "Set Comparator" mode. Metal oxide sensors used in conjunction with AirClean® OS can detect changes in filter condition and warn of filter failure.
The acid array monitors the airstream pH and is calibrated to alert the operator when levels of acid vapors meet the calibrated threshold limit.
Manual test with colorimetric gas sampling tubes provides the fourth means of filter validation and monitoring. Independence™ is designed to accommodate all major brands of colorimetric tubes. The sampling port is accessed from the front of Independence™.
Gas Detection Modes
There are two modes of operation for the PID gas analyzer, metal oxide array, and acid array sensor. These modes are "Set Measure" which is used exclusively with the PID analyzer and "Set Comparator" which is used with all three detectors found in Independence™.
Set Measure
The "Set Measure" is the first absolute zero reference measurement method found in a ductless fume hood. "Set Measure" creates a verifiable zero gas reference and an absolute reference gas measurement. This allows Independence™ to be the first ductless fume hood that truly can be field calibrated to give reliable gas measurements in PPM for either room air, Interfilter™ monitoring or hood exhaust air.
Set Comparator
"Set Comparator" is a method of detection pioneered by AirClean® Systems where a "clean air" measurement is taken during filter change and stored in memory. Subsequent measurements are compared to the "clean air" measurement. When the differential exceeds 50% TLV for the reference chemical, the user is alerted that filter change is imminent.
"Set Comparator" is a basic, proven method that requires no field calibration. However, it will not enable reporting in absolute PPM. Both "Set Measure" and "Set Comparator" gas detection methods can be used with the PID analyzer. "Set Comparator" can also be used with the metal oxide array sensor and acid array sensor.
