Calibration apparatus for air flow controllers

Apparatus for calibrating a pneumatically controlled HVAC system of ducts, thermostats and dampers comprising:

• a first input fitting attachable to a first source of air;
• a first output fitting;
• a first air pressure regulator interconnecting said first air input fitting and said first output fitting arranged and of a character to deliver air at a regulated pressure to said first output fitting;
• a second output fitting;
• a second air pressure regulator interconnecting said first air input fitting and said second output fitting arranged and of a character to deliver air at a regulated pressure to said second output fitting;
• a second input fitting attachable to a second source of air;
• and
• a first pressure sensor adapted and of a character to indicate the pressure at said second input fitting.

Apparatus for calibrating a pneumatic air control device in a pneumatically controlled HVAC system of ducts, fans, thermostats, and dampers, comprising:

• a first pneumatic input signal fitting adapted to receive a constant pressure pneumatic input signal;
• a first variable regulator in communication with said first pneumatic input signal fitting for generating a first pneumatic output signal;
• a first gauge to register said first pneumatic output signal;
• a second variable regulator in communication with said first pneumatic input signal fitting for generating a second pneumatic output signal;
• a second gauge to register said second pneumatic output signal;
• a second pneumatic input signal fitting adapted to receive a second pneumatic input signal generated by said control device in response to said first and second output signals;
• and
• a third gauge in communication with said second input signal fitting to register said second input signal.

A method of calibrating a pneumatically controlled HVAC system of ducts, thermostats and dampers, wherein a pneumatic controller which is operable in response to a first pneumatic signal from a thermostat in the system and to a second pneumatic signal from an air flow rate sensor in one of said ducts to transmit air from a source of relatively high pressure air to a damper actuator for a damper in said system, which comprises:

• transmitting air at a first predetermined pressure from said air source to said controller in place of said first pneumatic signal;
• transmitting air at a second preselected pressure from said air source to said controller in place of said second pneumatic signal;
• and
• detecting the pressure of air to be transmitted from said controller to said damper actuator in response to said first and second preselected signals.