No more guessing! An easy-to-use, easy-to-read gage to monitor filter media loading so that filter media may be changed when needed. The gage is installed between the blower and the filter, where a slight vacuum exists due to the air-flow resistance of the air filter. Air flowing into the gage, around the calibration screw, lifts a vane in proportion to the negative pressure in the blower compartment. As the air filter loads, the vacuum increases, raising the vane to indicate a filter change is necessary. The GeneralAire G99 Air Filter Gage may be calibrated in a negative pressure range from 0.1 to 0.4 inch w.c. When properly calibrated in this range a vacuum increase of 0.10 to 0.15 inch w.c. will indicate a filter change is necessary. Dial design is easy to read and interpret when filter needs to be changed. Easy to calibrate for new, clean media. Easy installation. Built-in filter screen removes dust from sampled ambient air to keep gage clean. May be mounted remotely up to 10 feet from monitoring location (with extension kit). Easy to disassemble/assemble for service.
OPERATION: Install a clean filter and run blower on highest speed. With a small screwdriver adjust the calibration screw, on the face of the gage, to put the pointer in the clear area in the center of the green "FILTER IS CLEAN" range.