AVT, Air Velocity Sensors

The AVT Series is a Duct mounted Air Velocity Sensor for HVAC application, with or without LCD Display.

The air velocity transmitter AVT is intended for air velocity measurement inside the ventilation duct in HVAC systems.

Model AVT 251 has selectable ranges of 0-5 m/s, 0-10 m/s, 0-15 m/s or 0-20 m/s.

Model AVT 551 has selectable ranges of 0-1 m/s, 0-2 m/s, 0-3 m/s or 0-5 m/s.

Both AVT 251 and AVT 551 have two outputs, 4-20 mA and 0-10 Vdc for Air Velocity measurement.

Air velocity accuracy is ±5 % for 0-20 m/s.

Temperature accuracy is 0.5°C at min 1 m/s.

Power supply requred is 24 Vac/dc.

Air Velocity Response time is 1 second or 5 seconds, DIP switch selectable

The sensors is located near the tip of the probe to measure air velocity and temperature inside the duct.

Ratings: IP65 for the enclosure and IP10 for the probe.

The air velocity transmitter AVT has 1 screw and 2 snap lids in the cover of the enclosure.

The wiring connection is inside the plastic enclosure on a terminal block.

The enclosure is supplied with a plastic cable entry gland.

The probe is made of plastic.

The air velocity transmitter AVT is supplied with a duct mounting flange for fast and easy mounting with a neoprene gasket for good sealing into the duct.

Penetration depth of the probe can be adjusted with the duct mounting flange.

Note: We Stock Model AVT 251 MDR2B, others are approx 4 weeks delivery

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Optional features for air velocity transmitters AVT 251 MDR2B and AVT 551 MDR2B

• Modbus RS485 communication

• LCD Display

• 2 x relay outputs

• Buzzer

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On request:

• Output 2-10 Vdc, 0-5 Vdc and 1-5 Vdc

• Output number 2 (AO2) can be supplied as
Temperature output instead of Air Velocity output.

• Other combination AVT types are in the datasheet.

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Ordering examples

AVT 251
Air Velocity transmitter
Ranges 0-5 m/s, 0-10 m/s, 0-15 m/s or 0-20 m/s, DIP switches selectable
Output 1 (AO1) : 4-20 mA
Output 2 (AO2) : 0-10 Vdc

AVT 551
Air Velocity transmitter
Ranges 0-1 m/s, 0-2 m/s, 0-3 m/s or 0-5 m/s, DIP switches selectable
Output 1 (AO1) : 4-20 mA
Output 2 (AO2) : 0-10 Vdc

AVT 251 MDR2B – Stocked Model
Air Velocity transmitter
Ranges 0-5 m/s, 0-10 m/s, 0-15 m/s or 0-20 m/s, DIP switches selectable
Output 1 (AO1) : 4-20 mA
Output 2 (AO2) : 0-10 Vdc
Modbus RS485 communication
LCD Display
2 x Relay outputs
Buzzer

AVT 551 MDR2B
Air Velocity transmitter
Ranges 0-1 m/s, 0-2 m/s, 0-3 m/s or 0-5 m/s, DIP switches selectable
Output 1 (AO1) : 4-20 mA
Output 2 (AO2) : 0-10 Vdc
Modbus RS485 communication
LCD Display
2 x Relay outputs
Buzzer

Download AVT air velocity transmitter datasheet for other types.
Note: Other types require min of 25pcs per order.

Technical data

Electrical

Power Supply                                    24 Vac (± %5), 50-60 Hz 15-35 Vdc
Power Consumption                           < 2.5 W

Outputs

Current Output                                 4-20 mA, maximum 500 Ω
Voltage Output                                 0-10 Vdc, minimum 1.000 Ω, 0-5 Vdc, minimum 1.000 Ω
Relay Output                                    max. rating 1A @ 220 Vac

Accuracy

Air Velocity                                      ± 5 % for 0-20 m/s
Temperature                                    0.5°C at min 1 m/s

General Data

Sensing Element                               Hotwire PT1200
Media                                               Air or non-aggressive gasses
Operating Temperature                      -25 to +70°C
Storage Temperature                         -30 to +85°C

Ranges Air Velocity

AVT 2                                               0-5 m/s, 0-10 m/s, 0-15 m/s, 0-20 m/s
AVT 5                                               0-1 m/s, 0-2 m/s, 0-3 m/s, 0-5 m/s

Range Temperature                       -30 to +70°C and 0 to +100°C

Connections

X1-X2                                               Terminals Pluggable screw terminal
X3                                                    terminals Fixed screw terminal
Cable                                                maximum 1.5mm2
Cable Gland                                      M16

Protection

Enclosure                                         IP65
Probe                                               IP10

Standards

EMC Directive                                   EN 61326-1
CE Conformity                                  CE1708

Dimensions

Enclosure                                         98.0 x 81.5 x 45.5 mm
Probe diameter                                 13 mm, length 255 mm
Packing (carton) dimensions              100 x 90 x 330 mm
Weight Packed                                  270 grams