• Airflow measurement unit based on differential pressure created by measurement probe pipes 
• Classification of casing leakage EN 1751 class C
• Inlet and outlet spigots have integral rubber gaskets
• Airflow transmitter installation allows 50 mm insulation

Accessories

• Integrated electronic airflow control unit

The casing of the measurement unit shall be made of galvanised steel.
The measurement probe pipes shall be made of aluminium.
The measurement unit shall have integral gaskets.

• Dimensions and Weight
• Material
• Function
• Installation
• Measurement
• Specification
• Order Code

Halton MSD

Airflow measurement unit for circle ducts

• Airflow measurement unit based on differential pressure created by measurement probe pipes 
• Very accurate measurement, inaccuracy less than ± 10%
• Classification of casing leakage EN 1751 class C
• Inlet and outlet spigots have integral rubber gaskets
• Airflow transmitter installation allows 50 mm insulation
   

Accessories

• Integrated electronic airflow control unit
   

Dimensions and Weight ▲

Halton MSD
- without electronic airflow controller  (MU=NA)

Halton MSD
- with electronic airflow control unit, VRD3 (MU=B)

Weight (kg)

Material ▲

Function ▲

Airflow in a duct creates a pressure difference between the front and rear probes.

The corresponding airflow rate can be defined by measuring the pressure difference sensed by the two crossing sets of averaging probes.

Installation ▲

In order to ensure the accuracy of the airflow measurement the safety distances between the measurement unit and flow disturbances (e.g. bends, T-branches) have to be respected. The necessary safety distances before and after different disturbances are presented in figures below.

The figure below describes also the recommended axial orientation of measurement probes related to bends and T-branches.

Measurement ▲

Connect the measurement tubes to the manometer and read the pressure difference. The airflow rate is calculated using the formula below or by reading the airflow rate directly from the diagram:

Defining flow measurement with electronic control unit

With model Halton MSD, MU=B airflow can be defined using integrated airflow control unit (VRD3). The actual measured airflow rate (qv) can be defined by the controller feedback signal (U5) and air flow measurement unit's nominal airflow (qv_nom).
 

Nominal airflow rates of Halton MSD are presented in the table below:

Wiring

Key:
1 (-)      24 VAC/DC system neutral
2 (+)     24 VAC/DC live
5 (U5)   0...10 / 2…10 VDC actual volumetric flow (
            switchable with ZTH-VAV, 0…100 % Vnom)

Airflow control unit (VRD3)

• Degree of protection: IP40
• Nominal supply voltage: AC 24 V, 50 / 60 Hz / DC 24 V
• Nominal supply voltage range: AC 19.2…28.8V / DC 21.6…28.8 V
• Power consumption: 2 W / 3.5 VA

Specification ▲

The casing of the measurement unit shall be made of galvanised steel.
The measurement probe pipes shall be made of aluminium.

The measurement unit shall have integral gaskets.

Order Code ▲

MSD-D,MU-ZT
 

D   = Connection size
         100, 125, 160, 200, 250, 315, 400, 500
 

Other Options and Accessories

MU = Electronic control unit
          NA    Not assigned
          B       Electronic airflow control unit (VRD3)

ZT = Tailored product
         N        No
         Y        Yes
 

Code example

            MSD-160, MU=NA, ZT=N