Method of backpressure testing manufactured parts

A method of backpressure testing manufactured parts, the method comprising:

• a) obtaining one or more reference parts and determining a reference backpressure measurement for each reference part indicative of the backpressure of that reference part when or if tested on a reference testing unit;
• b) calibrating one or more testing positions of a backpressure testing unit using the one or more reference parts;
• c) setting an upper backpressure limit and a lower backpressure limit for each of the one or more testing positions;
• and
• d) thereafter using the one or more testing positions to assess the backpressure of one or more manufactured parts;
• wherein, calibrating the one or more testing positions of the backpressure testing unit in step b) comprises:
• b) i) installing one of the reference parts in a or each testing position of the backpressure testing unit;
• b) ii) creating a flow through the or each testing position;
• b) iii) establishing a calibrated flow for the or each testing position by adjusting the flow through the or each testing position until a backpressure measurement of the reference part in the or each testing position corresponds to the reference backpressure measurement of the respective reference part;
• b) iv) thereafter using the calibrated flow for the or each testing position during step d);
• wherein, using the one or more testing positions to assess the backpressure of one or more manufactured parts in step d) comprises:
• d) i) installing a manufactured part in a or each testing position of the backpressure testing unit;
• d) ii) flowing the calibrated flow determined from step b) iii) through the or each testing position;
• d) iii) measuring a backpressure measurement of the or each manufactured part;
• d) iv) comparing the backpressure measurement of the or each manufactured part against the upper backpressure limit and the lower backpressure limit for the respective testing position and generating and outputting a test result indicative of whether the backpressure measurement is within an acceptable range compared to the upper backpressure limit and the lower backpressure limit.