Gentek 3950202, 3940200, 3950320, 3940421, 3940320, 3940402 Operation, Digital 1000 Calibration

Chapter 6: Maintaining Your Filtered Enclosure

Operation

The Guardian Digital Airflow Monitor consists of the airflow sensor, the Alarm Unit, and the 15 VDC power supply. For 115V operation the alarm unit is powered by plugging the power supply into the factory-prepared digital airflow monitor socket. For 230V operation, the Alarm Unit is powered by plugging the power supply into a building outlet. The alarm has “Enter,” “+,” and “-” buttons to program the monitor. There is also a green LED “SAFE,” yellow LED “CAUTION,” and red LED “LOW” with audible alarm for airflow conditions. The audible alarm can be permanently muted if desired. The Guardian Digital 1000 Airflow Monitor displays a face velocity value, provides an RS232 communications port to a PC or building computer system, can be configured for external input connections such as night setback or external alarm and provides up to three output relays that can be configured. For complete detailed information, please refer to the separate Labconco 1000 Alarm User’s Manual provided with the enclosure.

Digital 1000 Calibration

The filtered enclosure comes factory calibrated with the monitor alarm at 60 ± 10 fpm with the inflow velocity set at 90± 10 fpm. To change the calibration, review the Labconco 1000 Alarm User’s Manual that comes with the enclosure. To successfully calibrate, it will be necessary to change the face velocity by adjusting the airflow exhaust volume with the speed control. The exhaust volume can be adjusted with the speed control or by using an adjustable damper for outside exhaust. NOTE: For accurate calibration, the front panel needs to be in place for each low calibration and high calibration set points to simulate real usage.

Typical calibration conditions are set at face velocity air sample differences of a least 50 feet per minute. However, the airflow monitor is factory set and calibrated with a difference of at least 20 fpm and can be changed in the CAL CONFIG MENU by changing the “lower/higher air sample difference.” If changed, then also change the “sensor difference” in CAL CONFIG MENU from

10% to 3%. To change the red “Low” airflow alarm and yellow “CAUTION” adjust the values in CAL CONFIG MENU. Set “WARNING or CAUTION” air reset to 3 fpm. To complete the CAL CONFIGURATION, be sure to enter “Done.”

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