The Cobra model duct leakage tester is a great all around tester. It can test 90 to 95% of the jobs you’ll encounter. If you don’t plan on testing at pressures greater than 9 in.wg., you can’t go wrong with the Cobra. Standard unit includes digital gauges and panel mounted variable speed controller, but you can opt for analog gauges and/or inlet damper instead.
Measure leakage from 9 to 680 cfm
115v/1ph operation
Variable speed controller
Quick-change orifice plates
Digital gauges (9v operation)
12-1/2 ft flex (5-inch diam.)
20 ft pressure tubing
Calibration certificates
15 amp circuit
No-flat tires
Upper locking swivel casters
Everything labeled for easy use!
Use the table below to determine the range of air leakage you can test with the Cobra using our standard orifice plates.
| Test Pressure (in.wg.) | Recommended Flow Range of Orifice Plate | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Optional Low-Flow Plate | 1 in Plate | 2 in Plate | 3 in Plate | 4 in Plate | ||||||
| Min Flow | Max Flow | Min Flow | Max Flow | Min Flow | Max Flow | Min Flow | Max Flow | Min Flow | Max Flow | |
| (cfm) | (cfm) | (cfm) | (cfm) | (cfm) | (cfm) | (cfm) | (cfm) | (cfm) | (cfm) | |
| 0.1 | 1 | 11 | 9 | 47 | 34 | 182 | 82 | 440 | 175 | 680 |
| 1 | 1 | 10 | 9 | 44 | 34 | 170 | 82 | 420 | 175 | 650 |
| 2 | 1 | 10 | 9 | 42 | 34 | 165 | 82 | 410 | 175 | 645 |
| 3 | 1 | 9 | 9 | 39 | 34 | 155 | 82 | 390 | 175 | 625 |
| 4 | 1 | 8 | 9 | 36 | 34 | 140 | 82 | 375 | 175 | 600 |
| 5 | 1 | 7 | 9 | 32 | 34 | 125 | 82 | 340 | 175 | 540 |
| 6 | 1 | 7 | 9 | 29 | 34 | 115 | 82 | 290 | 175 | 465 |
| 7 | 1 | 6 | 9 | 24 | 34 | 95 | 82 | 245 | 175 | 405 |
| 8 | 1 | 4 | 9 | 19 | 34 | 75 | 82 | 195 | 175 | 350 |
| 9 | 1 | 3 | 9 | 12 | 34 | 46 | 82 | 130 | 175 | 250 |
- Min Leakage is the recommended minimum flow rate based on a 0.4 in.wg. pressure drop across the orifice plate. For example, approximately 82 cfm through the 3-inch orifice plate results in a 0.4 in.wg. so 82 cfm is the recommended minimum leakage. Though it possible to use the orifice plates at pressure drops lower than 0.4 in.w.g, note that accuracy of the reading is decreased.
- Note that the data is based on laboratory tests with short lengths of hard pipe attached to the duct leakage tester. Actual field performance will likely result in reduced performance due to: (1) amount of flexible duct used; (2) number of bends in flexible duct; (3) size of duct system; (4) line voltage. To account for flexible duct and 90 degree bends, use our program that takes these in-line losses into account.
Use the table below to determine the range of air leakage you can test with the Cobra using our standard orifice plates.
| Test Pressure (Pa) | Recommended Flow Range of Orifice Plate | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Optional Low-Flow Plate | 25mm Plate | 50mm Plate | 75mm Plate | 100mm Plate | ||||||
| Min Flow | Max Flow | Min Flow | Max Flow | Min Flow | Max Flow | Min Flow | Max Flow | Min Flow | Max Flow | |
| (L/s) | (L/s) | (L/s) | (L/s) | (L/s) | (L/s) | (L/s) | (L/s) | (L/s) | (L/s) | |
| 25 | 0.5 | 5.2 | 4.2 | 22 | 16 | 86 | 39 | 208 | 83 | 321 |
| 250 | 0.5 | 4.7 | 4.2 | 21 | 16 | 80 | 39 | 198 | 83 | 307 |
| 500 | 0.5 | 4.7 | 4.2 | 20 | 16 | 78 | 39 | 193 | 83 | 304 |
| 750 | 0.5 | 4.2 | 4.2 | 18 | 16 | 73 | 39 | 184 | 83 | 295 |
| 1000 | 0.5 | 3.8 | 4.2 | 17 | 16 | 66 | 39 | 177 | 83 | 283 |
| 1250 | 0.5 | 3.3 | 4.2 | 15 | 16 | 59 | 39 | 160 | 83 | 255 |
| 1500 | 0.5 | 3.3 | 4.2 | 14 | 16 | 54 | 39 | 137 | 83 | 219 |
| 1750 | 0.5 | 2.8 | 4.2 | 11 | 16 | 45 | 39 | 116 | 83 | 191 |
| 2000 | 0.5 | 1.9 | 4.2 | 9.0 | 16 | 35 | 39 | 92 | 83 | 165 |
| 2250 | 0.5 | 1.4 | 4.2 | 5.7 | 16 | 22 | 39 | 61 | 83 | 118 |
- Min Leakage is the recommended minimum flow rate based on a 100 Pa pressure drop across the orifice plate. For example, approximately 39 L/s through the 75 mm orifice plate results in a 100 Pa so 39 L/s is the recommended minimum leakage. Though it possible to use the orifice plates at pressure drops lower than 100 Pa, note that accuracy of the reading is decreased.
- Note that the data is based on laboratory tests with short lengths of hard pipe attached to the duct leakage tester. Actual field performance will likely result in reduced performance due to: (1) amount of flexible duct used; (2) number of bends in flexible duct; (3) size of duct system; (4) line voltage. To account for flexible duct and 90 degree bends, use our program that takes these in-line losses into account.
Options
Analog gauges
Inlet damper operation
Low-flow orifice plate (1 to 10 cfm)
230v/1ph operation