Method for calibrating a differential pressure fluid flow measuring system

For a differential pressure flow measuring system comprising a primary flow sensor and a secondary electro-mechanical conversion apparatus for converting high and low fluid pressure signals from the primary flow sensor to an electronic signal output representative of fluid flow, a system calibration process, comprising the steps of;

• applying a plurality of known reference fluid flow rates to the primary flow sensor over the system's operative range of flow conditions,
• sensing the electrical output of the secondary electronic conversion apparatus for each of the said plurality of reference fluid flow rates;
• establishing a correction factor for each of the plurality of reference flow rates which will tend to characterize a desired relationship between the fluid flow rate and the electrical output of the measuring system, and
• storing the correction factors in non-volatile memory.

A system calibration process for differential pressure flow measurement in a system having fluid flowing in a confined conduit, and having a primary flow sensor and a secondary electro-mechanical conversion apparatus, including electronic memory, for converting high and low fluid pressure signals derived from the primary flow sensor to an electric signal representative of fluid flow, comprising the steps of;

• sensing the fluid impact pressure and the fluid static low pressure for a plurality of known reference fluid flows to establish a plurality of high and low pressure signals over a range of fluid flows,
• transducing the said high and low pressure signals into measured electrical differential pressure signals representative of the difference between the sensed high and low pressure for each of the plurality of reference flow rates,
• establishing a desired relationship between the reference flow rates and the electrical output of the secondary apparatus for each of the plurality of the reference flow rates,
• overwriting into the electronic memory the said established desired relationship of the secondary apparatus.

For a differential pressure flow measuring system comprising a primary flow sensor and a secondary electro-mechanical conversion apparatus for convening high and low fluid pressure signals from the primary flow sensor to an electronic signal output representative of fluid flow, a system calibration process, comprising the steps of;

• applying a plurality of known reference fluid flow rates to the primary flow sensor over the system's operative range of flow conditions,
• sensing the electrical output of the secondary electronic conversion apparatus for each of the said plurality of reference fluid flow rates;
• establishing a correction factor for each of the plurality of reference flow rates which will tend to linearize the relationship between fluid flow rate and the electrical output of the measuring system as a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the plurality of reference flow rates,
• storing the correction factors in non-volatile memory, and
• initially linearizing the secondary electro-mechanical apparatus against known pressure over the operating range of the apparatus to obtain data for linearizing the output of the said electro-mechanical apparatus.

For a differential pressure flow measuring system comprising a primary flow sensor and a secondary electro-mechanical conversion apparatus for converting high and low fluid pressure signals from the primary flow sensor to an electronic signal output representative of fluid flow, a system calibration process, comprising the steps of;

• applying a plurality of known reference fluid flow rates to the primary flow sensor over the system's operative range of flow conditions,
• sensing the electrical output of the secondary electronic conversion apparatus for each of the said plurality of reference fluid flow rates;
• establishing a correction factor for each of the plurality of reference flow rates which will tend to linearize the relationship between fluid flow rate and the electrical output of the measuring system as a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the plurality of reference flow rates,
• storing the correction factors in non-volatile memory,
• initially linearizing the secondary electro-mechanical apparatus against known pressure over the operating range of the apparatus to obtain data for linearizing the output of the said electro-mechanical apparatus, and
• modifying the initial linearization data for the secondary electro-mechanical apparatus with the determined correction factors.

A system calibration process for differential pressure flow measurement in a system having fluid flowing in a confined conduit, and having a primary flow sensor and a secondary electro-mechanical conversion apparatus, including electronic memory, for converting high and low fluid pressure signals derived from the primary flow sensor to an electric signal representative of fluid flow, comprising the steps of;

• sensing the fluid impact pressure and the fluid static low pressure for a plurality of known reference fluid flows to establish a plurality of high and low pressure signals over a range of fluid flows,
• transducing the said high and low pressure signals into measured electrical differential pressure signals representative of the difference between the sensed high and low pressure for each of the plurality of reference flow rates,
• establishing a desired relationship between the reference flow rates and the electrical output of the secondary apparatus for each of the plurality of the reference flow rates at a function of the deviation of each value of measured differential pressure from the nominal differential pressure corresponding to each of the plurality of reference flow rates,
• overwriting into the electronic memory the said established desired relationship of the secondary apparatus, and
• initially characterizing the secondary electro-mechanical apparatus against known pressures over the operating range of the apparatus to obtain data for characterizing the output of the said electro-mechanical apparatus.