Air Measuring Control Dampers

Greenheck airflow measuring products are available with either differential pressure based technology or thermal dispersion technology. AMS is accurate air flow measuring station with pressure transmitter proportional to air flow, while AMD is control air damper combined with airflow measuring station for monitoring and control of air flow. AMD-TD is control air damper with airflow measuring station based on thermal dispersion technology.


Air Measuring Product & Control
Make: Greenheck, USA
Model: AMS
The AMS is an accurate airflow measuring station and is furnished with a properly sized pressure transducer that outputs a signal proportional to cfm. The AMS is compatible with a field supplied controller or a factory supplied LON controller that uses a signal to position a damper (sold separately) to the airflow required.

Model AMS
Air measuring station
Model: AMD – Pressure Differential
The AMD series combines the function of an accurate airflow measuring station and a low leakage control damper into one compact assembly that both measures and regulates airflow volumes to a target set-point. The AMD series is compatible with a field supplied controller or a factory supplied LON controller. The four available models are:
• AMD-23 featuring a 3V blade control damper
• AMD-33 featuring a fabricated airfoil blade control damper
• AMD-42 featuring an extruded airfoil blade control damper and
• AMD-42V featuring a vertical extruded airfoil blade control damper.

Model AMD - Pressure Differential
Air measuring station with pressure differential
Model: AMD-TD – Thermal Dispersion
Vari-Green® airflow measurement probes and transmitters utilize thermal dispersion technology to accurately measure airflow down to 0 fpm. Each probe comes with one or more airflow measuring nodes that contain a pair of precision matched thermistors. In each node one thermistor measures the ambient air temperature and the other is heated to a preset temperature differential above ambient. The air velocity is measured at each node by using the known relationship between heat transfer and air velocity and by measuring the power consumption necessary to maintain the fixed temperature difference between the thermistors. The Vari-Green transmitter then averages the velocities at each node to determine the overall cfm going through the AMD. There are four models available:
•AMD-23-TD 3V style blades
•AMD-33-TD fabricated airfoil blades
•AMD-42-TD extruded aluminum blades
•AMD-42V-TD vertically oriented extruded aluminum blades

Model AMD-TD - Thermal Dispersion
Air measuring station with thermal dispersion