Installation Instructions

OPERATION INSTRUCTIONS

Pressure Differential Measurements between

Sampling and Return Tubes Using the 8883

with Conventional/Addressable Air Duct Detectors

This procedure describes the proper method of verifying that the pressure differential between the

air duct inlet tube and outlet sampling tube is between .01 and 1.0 inches of water column.

1 Remove the air duct detector cover and the detector.

2. Ensure that the air duct housing and its sampling and return tubes are properly installed and oriented on the

air duct facility. See Step 9 below.

3. Remove the pressure differential gauge (Item A), the rubber tubing adapters (Item C), and the flexible

hoses (Item B) from the carrying case.

4. Connect one flexible hose to the high pressure port of the gauge and the other hose to the low pressure port

of the gauge.

5. Slide the metal connector of the rubber tubing adapter (Item C) into the other end of each flexible hose. Be

certain that the hose ends are completely seated at each end connection to ensure a proper seal.

6. Mount the gauge to a vertical magnetic surface as close to the air duct housing under test as possible. The

magnets on the back of the gauge will stabilize the meter.

Check that the indicating pointer is near the zero mark. If the pointer is less than one division away from the

zero mark, proceed to Step 7 below. If the pointer is more than one division away from the zero mark, the

meter will give an inaccurate indication, possibly because the mounting surface is not vertical. Correct this

condition before proceeding.

7. Attach the open stopper end of each assembled flexible hose to the air duct housing sample tube port.

NOTE: Connect the tubing from the high pressure port of the gauge to the sampling tube closest to the

electrical wiring compartment of the air duct housing, and connect the tubing from the low pres-

sure port of the gauge to the sampling tube away from the electrical wiring compartment of the air

duct housing.

8. With air flowing through the duct, the reading should be between .01 inch and 1.0 inches of water column.

The graduations of the meter represent .025 inch of water column at each graduation measured between 0

and 1.0 inch and .05 inch of water column measured between 1.0 inch and 1.5 inches.

If the meter reading is not between .01 inch and 1.0 inches of water column, any of three conditions (a, b, or c)

may exist:

a. The sampling tubes are not oriented correctly, or

b. The air velocity in the duct is below 400fpm, or

c. The air velocity in the duct is above 4000fpm.

The correct sampling tube orientation can be found in the appropriate air duct installation instructions. If the

sampling tubes are misoriented, correct the orientation and repeat the pressure measurement.

10. Remove flexible hose assembly and the equipment. Reassemble the air duct detector and cover. Securely

tighten the cover with fastening screws. Do not overtighten, as that may result in air leakage around the

edges of the cover.

P/N 315-085535FA-4

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OPERATION INSTRUCTIONS Pressure Differential Measurements between Sampling and Return Tubes Using the 8883 with Conventional/Addressable Air Duct Detectors This procedure describes the proper method of verifying that the pressure differential between the air duct inlet tube and outlet sampling tube is between .01 and 1.0 inches of water column. 1 Remove the air duct detector cover and the detector. 2.
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8 Fernwood Road Florham Park, New Jersey 07932 P/N 315-085535FA-4 Model 8883 Air Duct Pressure Differential Meter THIS KIT CONTAINS: ITEM A B C DESCRIPTION PRESSURE DIFFERENTIAL GAUGE RUBBER HOSE, 54 INCHES TUBE ADAPTER QTY 1 2 2 P/N 315-085535FA-4