Air Flow Probe

Description

The AV-FP range of economical airflow sensors measures differential (velocity) pressure in VAV units and other locations within main or branch ducts. Four lengths allow the sensor to be selected to yield accurate readings of terminal unit inlet diameters from 100mm to 500mm.
The sensor operates by measuring the velocity pressure using a differential pressure transmitter such as the PTH-3202.

Specification

Mounting:           Integral flange with gasket.
Connections:     ¼” nipples for ⅜” OD polyethene tubing.
Ambient:             0°C to 50°C

av-fp1002

The Series PAFS-1000 Averaging Flow Sensor is ideal for measuring differential pressure in the inlet section of variable-air-volume terminal units and fan terminal units. Units can also be used to sense differential pressure at other locations in the main or branch duct systems.
The “H” port senses total pressure, and the “L” port senses static pressure. The difference between these signals is the differential, or velocity pressure.
Models offer up to 10 sensing points and lengths ranging from 3-5/32″ to 23-29/32″ (8.02 to 60.72 cm), accommodating box sizes from 4″ to 30″ (10.16 to 76.20 cm).

INSTALLATION

The Series PAFS-1000 utilises 1/4″ ID, 3/8″ OD tubing. First, check that there are no sharp bends in the tubing at any connection. Bends and creases may leak over time as the tubing ages.

Connect the “H” Port to the high input on the differential pressure gauge. transmitter, or switch.
Connect the “L” Port to the low input on the differential pressure gauge. transmitter, or switch.

Approximate K factors for models:
PAFS-1002: 1.32
PAPS-1003: 1.39
PAFS-1004: 1.46
PAPS-1005: 1.46

It may be necessary to calibrate to ensure accurate measurement. You can do this by traversing the duct or fan to determine the PAPS-sensed delta P vs. the actual flow.

MOUNTING

1. Install the unit horizontally to assure accurate velocity readings for units ranging from 3-5/32″ to 9-29/32″. If using a unit longer than the PAPS-1005, which is 0- 29/32-, vertical mounting is recommended.
2. Determine the duct’s flow direction and install the Series PAPS-1000 based on the unit’s flow arrow imprint.
3. Cut a 7/8″ hole in the ducting to accept the unit.
4. Attach using two self-tapping screws inserted in the 3/16″ mounting holes.

Model Number of Sensing Points Sensor Length

PAPS-1002 3-5/32- (8.02 cm)
PAFS-1003 5-13/32″ (13.73 cm)
PAFS-1004 7-21/32″ (19.55 cm)
PAFS-1005 9-29/32″ (25.26 cm)

SPECIFICATIONS

Service: Air and compatible gases.
Wetted Materials: ABS/polycarbonate (1JL94-5V).
Temperature Limits: Operating: 40 to 120°F (4 to 49°C);
Storage: -40 to 140°F (-40 to 60°C).
Connection: 1/4″ (6 mm) ID, 3/8″ (10 mm) OD tubing.
Mounting Orientation: Integral flange with gasket.
Weight: 1 oz (28 g).

MAINTENANCE

Sensing orifices must be kept free of dust accumulation or debris. Occasional cleaning may be required.
Upon final installation of the Series PAPS-1000 Averaging Flow Sensor, no routine maintenance is required. Periodic checks of system calibration are recommended. The Series PAPS-1000 is not field serviceable and should be returned if repair is needed (field repair should not be attempted and may void warranty).

Be sure to include a brief description of the problem plus any relevant application notes.
Contact customer service to receive a return goods authorisation number before shipping.