System Sensor Differential Pressure Testing Using Analog and Digital Manometers

White Paper 2012 Pressure Testing Analog and Digital Manometers Differential Pressure Testing Using Analog and Digital Manometers test assumes that your duct smoke detector is installed correctly and meets all requirements per the model s specific installation instructions You need the following parts to perform this test 1 Parts Manometer Dwyer Magnehelic Series 2000 OR Manometer Dwyer Seiries 475 MARK III Tubing inch Rubber Stoppers Verify that the manometer operating requirements are satisfied e g temperature max Analog 15 PSI Digital 150 in W C etc Verify and note current manometer reading and adjust if necessary With the duct smoke detector cover removed plug the manometer positive end for Digital or HIGH end for Analog into the sampling tube end 2 Digital and Analog Meters 3 Sampling Tube End 4 Analog and LOW 5 Digital and Negative Plug the manometer negative end for Digital or LOW end for Analog into the exhaust tube end Sensor Advanced Ideas Advanced Solutions 6 Exhaust Tube Placement Differential Pressure Testing Using Analog and Digital Manometers Measure differential pressure on the Digital meter and read the measurement on the Analog meter 7 Digital Meter 8 Analog Meter The D4120 is designed to operate over an extended airspeed of 100 to 4,000 FPM To verify sufficient sampling of ducted air turn the air handler on and use the to measure the differential pressure between the two sampling tubes The differential pressure should measure at least 0.01 inches of water and no than 1.11 inches of water Because most commercially available manometers cannot accurately measure very low pressure differentials applications with less 500 FPM of airspeed may require the use of a current sourcing pressure transmitter Dwyer Series 607 or the use of aerosol smoke per sections shown below Flow AirFlow Test Using Dwyer Series 607 Differential Pressure Transmitter the air speed of the duct using an anemometer Air speed must be at least 100 FPM Wire the Dwyer transmitter as shown in Figure 9 Connect leads of the meter to either side of the 1,000 resistor Allow unit to warm up for 15 seconds With both HIGH and LOW pressure ports open to air measure and record the voltage drop across the 1,000 resistor measurement 1 4.00 volts is typical Using flexible tubing and rubber connect the HIGH side of the transmitter to the sampling tube of the duct smoke detector housing and the LOW side of the transmitter to exhaust tube of the duct smoke detector housing Measure and record the voltage drop across the 1,000 resistor measurement 2 Subtract the recorded in measurement 1 from the voltage recorded in measurement 2 If the difference is greater than 0.15 volts there is enough airflow the duct smoke detector for proper operation 9 Dwyer Transmitter Wiring SAMPLING TUBE EXHAUST TUBE 607 0 TO 36VDC VOLT VOLT VOLT OHM 5 1 WATT RESISTOR METER MODEL 87 EQUIVALENT Entry using Aerosol Smoke test is intended for low flow systems 100 500 FPM If the air speed is greater than 500 FPM use a conventional manometer to measure pressure between the sampling tubes as described above Drill a inch hole 3 feet upstream from the duct smoke detector With the handler on measure the air velocity with an anemometer Air speed must be at least 100 FPM Spray aerosol smoke into the duct through the inch hole for five seconds Wait two minutes for the duct smoke detector to alarm If the duct smoke detector alarms air is flowing through the Remove the duct smoke detector cover and blow out the residual aerosol smoke from the chamber and reset the duct smoke detector Use tape to seal the aerosol smoke entry hole Aerosol smoke can be purchased from Home Safeguard Industries at homesafeguard com model 25S Smoke Detector Tester and Chekkit Smoke Detector Tester model and CHEK06 available from SDi When used properly the canned smoke agent will cause the smoke detector to go into alarm Refer to the manufacturer instructions for proper use of the canned smoke agent aerosol simulated smoke canned smoke agent formulas will vary by manufacturer Misuse or overuse to these products may have long term effects on the smoke detector Consult the canned smoke agent manufacturer published instructions for any further warnings or caution Sensor Advanced Ideas Advanced Solutions Differential Pressure Testing Using Analog and Digital Manometers check the following if the differential pressure measurements are outside the specified range 0.01 1.11 inches of water that the air velocity in the duct is within the specified range If necessary use a velocity meter anemometer to check the air velocity the duct the sampling tube is installed with the air inlet holes facing into the airflow To assist proper installation the tube connector is marked an arrow Make sure the sampling tube is mounted so that the arrow points into the airflow as shown in Figure 10 Note that the sampling and exhaust tube can be mounted in either housing connection as long as the exhaust tube is mounted downstream from the sampling 10 Sampling Tube Airflow TUBE ENDCAP MUST FACE AIRFLOW that the end cap is installed at the end of the sampling tube The sampling tube end cap included with the detector is critical to proper of the duct smoke detector The end cap is needed to create the proper airflow to the sensor of the duct smoke detector that the sampling tube extends to a minimum of duct width that the duct smoke detector unit is properly sealed to the duct more information please contact Sensor Ohio Avenue Charles Illinois 60174 1 800 sensor2 System Sensor Product specifications subject to change without notice 1 12