ACI A/PT-DLP : 7 in Aluminum Duct-Static Pitot Tube for DLP Series, 6.75 in Insertion Length, Barbed Tubing Fittings (6 places), 5-Year Warranty

The A/PT-DLP is a 7 in aluminum duct-static pitot tube with a 6.75 in insertion length, originally specified as the OEM-paired pitot tube for ACI's DLP Series differential pressure transmitter. Functionally it's the same kind of static / aspiration probe as the SPT series — the differences are the specific dimensions (7 in overall vs. the SPT-3.5 in or SPT-8 in lengths) and the OEM packaging. It works with any low-DP differential pressure transmitter that accepts 1/8 to 1/4 in tubing, not just ACI DLP units.

The probe tip orientation: static probes like the SPT mount with the tip parallel to the air stream (the tip opening points sideways relative to the flow); velocity / impact probes like the ACI VPT mount with the tip facing into the air stream (the tip opening points upstream into the flow). Static probes measure pressure only; velocity probes measure total pressure (static + dynamic), which is then used to compute air velocity / flow rate. Use the static probe for filter-status, fan-operation, or duct static monitoring; use the velocity probe for true air flow measurement.

It works with any low-DP differential pressure transmitter that accepts 1/8 to 1/4 in flexible tubing on the high- or low-pressure port. The 'DLP' suffix reflects its origin as the OEM-paired pitot tube for ACI's DLP Series transmitter, but there's no electronic interfacing — the probe is a passive pneumatic pickup. If you're not using a DLP transmitter, see SPT-3.5" or SPT-8.0" for alternative length options at similar price points.

Approximately 5 to 8 duct diameters downstream from elbows, obstructions, transitions, or other large changes in duct area — this places the probe where turbulence has settled out and the static pressure reading is most representative. Drill a 3/8 in hole in the duct, insert the probe through the hole until the flange is tight to the duct, drill pilot holes for the four #8 x 3/4 in TEK mounting screws (not included), and fasten the flange tightly to eliminate air leaks. Mount perpendicular to the duct with the probe tip parallel to the air stream.

The probe accepts 1/8 in through 1/4 in ID flexible plastic tubing. For long runs, 1/4 in tubing minimizes pressure drop in the line. ACI offers FDA-compliant medical-grade flexible PVC tubing kits in 10 ft, 20 ft, 50 ft, and 100 ft lengths. Keep the run as short as practical to minimize response time; avoid sharp bends and low points where condensation can collect.

Any low-DP differential pressure transmitter that accepts 1/8 to 1/4 in flexible tubing on the high- or low-pressure ports — including ACI's own DLP and MLP2 series, BAPI ZPM zone pressure multi-sensors, Dwyer Series 682 industrial pressure transmitters (when configured for duct static monitoring), Dwyer RSM / RSME / RSMC room status monitors, and most other manufacturers' low-DP air pressure transmitters. The probe is a passive pneumatic accessory; brand compatibility is determined by the tubing fitting size, not by electronic interfacing.